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Postgres FD Implementation
Commit d96c29ab authored by Dave Cramer's avatar Dave Cramer
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Applied Anders patch to move the startup code out of Connection into StartupPacket 

* Introduces a new class, StartupPacket.
* Moves a lot of constants from Connection to StartupPacket.
* Makes two instance variables in Connection into locals.
parent 8e9b215f
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src/interfaces/jdbc/org/postgresql/Connection.java
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package org.postgresql;
import java.io.*;
import java.net.*;
import java.sql.*;
import java.util.*;
import org.postgresql.Field;
import org.postgresql.fastpath.*;
import org.postgresql.largeobject.*;
import org.postgresql.util.*;
import org.postgresql.core.*;
/*
* $Id: Connection.java,v 1.43 2002/03/09 17:08:39 davec Exp $
*
* This abstract class is used by org.postgresql.Driver to open either the JDBC1 or
* JDBC2 versions of the Connection class.
*
*/
public abstract class Connection
{
// This is the network stream associated with this connection
public PG_Stream pg_stream;
private String PG_HOST;
private int PG_PORT;
private String PG_USER;
private String PG_PASSWORD;
private String PG_DATABASE;
private boolean PG_STATUS;
private String compatible;
/*
* The encoding to use for this connection.
*/
private Encoding encoding = Encoding.defaultEncoding();
private String dbVersionNumber;
public boolean CONNECTION_OK = true;
public boolean CONNECTION_BAD = false;
public boolean autoCommit = true;
public boolean readOnly = false;
public Driver this_driver;
private String this_url;
private String cursor = null; // The positioned update cursor name
// These are new for v6.3, they determine the current protocol versions
// supported by this version of the driver. They are defined in
// src/include/libpq/pqcomm.h
protected static final int PG_PROTOCOL_LATEST_MAJOR = 2;
protected static final int PG_PROTOCOL_LATEST_MINOR = 0;
private static final int SM_DATABASE = 64;
private static final int SM_USER = 32;
private static final int SM_OPTIONS = 64;
private static final int SM_UNUSED = 64;
private static final int SM_TTY = 64;
private static final int AUTH_REQ_OK = 0;
private static final int AUTH_REQ_KRB4 = 1;
private static final int AUTH_REQ_KRB5 = 2;
private static final int AUTH_REQ_PASSWORD = 3;
private static final int AUTH_REQ_CRYPT = 4;
private static final int AUTH_REQ_MD5 = 5;
// New for 6.3, salt value for crypt authorisation
private String salt;
// These are used to cache oids, PGTypes and SQLTypes
private static Hashtable sqlTypeCache = new Hashtable(); // oid -> SQLType
private static Hashtable pgTypeCache = new Hashtable(); // oid -> PGType
private static Hashtable typeOidCache = new Hashtable(); //PGType -> oid
// Now handle notices as warnings, so things like "show" now work
public SQLWarning firstWarning = null;
/*
* Cache of the current isolation level
*/
private int isolationLevel = java.sql.Connection.TRANSACTION_READ_COMMITTED;
// The PID an cancellation key we get from the backend process
public int pid;
public int ckey;
/*
* This is called by Class.forName() from within org.postgresql.Driver
*/
public Connection()
{}
public void cancelQuery() throws SQLException
{
PG_Stream cancelStream = null;
try {
cancelStream = new PG_Stream(PG_HOST, PG_PORT);
} catch (ConnectException cex) {
// Added by Peter Mount <peter@retep.org.uk>
// ConnectException is thrown when the connection cannot be made.
// we trap this an return a more meaningful message for the end user
throw new PSQLException ("postgresql.con.refused");
} catch (IOException e) {
throw new PSQLException ("postgresql.con.failed",e);
}
// Now we need to construct and send a cancel packet
try {
cancelStream.SendInteger(16, 4);
cancelStream.SendInteger(80877102, 4);
cancelStream.SendInteger(pid, 4);
cancelStream.SendInteger(ckey, 4);
cancelStream.flush();
}
catch(IOException e) {
throw new PSQLException("postgresql.con.failed",e);
}
finally {
try {
if(cancelStream != null)
cancelStream.close();
}
catch(IOException e) {} // Ignore
}
}
/*
* This method actually opens the connection. It is called by Driver.
*
* @param host the hostname of the database back end
* @param port the port number of the postmaster process
* @param info a Properties[] thing of the user and password
* @param database the database to connect to
* @param u the URL of the connection
* @param d the Driver instantation of the connection
* @return a valid connection profile
* @exception SQLException if a database access error occurs
*/
protected void openConnection(String host, int port, Properties info, String database, String url, Driver d) throws SQLException
{
firstWarning = null;
// Throw an exception if the user or password properties are missing
// This occasionally occurs when the client uses the properties version
// of getConnection(), and is a common question on the email lists
if (info.getProperty("user") == null)
throw new PSQLException("postgresql.con.user");
this_driver = d;
this_url = url;
PG_DATABASE = database;
PG_USER = info.getProperty("user");
PG_PASSWORD = info.getProperty("password", "");
PG_PORT = port;
PG_HOST = host;
PG_STATUS = CONNECTION_BAD;
if (info.getProperty("compatible") == null)
{
compatible = d.getMajorVersion() + "." + d.getMinorVersion();
}
else
{
compatible = info.getProperty("compatible");
}
// Now make the initial connection
try
{
pg_stream = new PG_Stream(host, port);
}
catch (ConnectException cex)
{
// Added by Peter Mount <peter@retep.org.uk>
// ConnectException is thrown when the connection cannot be made.
// we trap this an return a more meaningful message for the end user
throw new PSQLException ("postgresql.con.refused");
}
catch (IOException e)
{
throw new PSQLException ("postgresql.con.failed", e);
}
// Now we need to construct and send a startup packet
try
{
// Ver 6.3 code
pg_stream.SendInteger(4 + 4 + SM_DATABASE + SM_USER + SM_OPTIONS + SM_UNUSED + SM_TTY, 4);
pg_stream.SendInteger(PG_PROTOCOL_LATEST_MAJOR, 2);
pg_stream.SendInteger(PG_PROTOCOL_LATEST_MINOR, 2);
pg_stream.Send(database.getBytes(), SM_DATABASE);
// This last send includes the unused fields
pg_stream.Send(PG_USER.getBytes(), SM_USER + SM_OPTIONS + SM_UNUSED + SM_TTY);
// now flush the startup packets to the backend
pg_stream.flush();
// Now get the response from the backend, either an error message
// or an authentication request
int areq = -1; // must have a value here
do
{
int beresp = pg_stream.ReceiveChar();
switch (beresp)
{
case 'E':
// An error occured, so pass the error message to the
// user.
//
// The most common one to be thrown here is:
// "User authentication failed"
//
throw new PSQLException("postgresql.con.misc", pg_stream.ReceiveString(encoding));
case 'R':
// Get the type of request
areq = pg_stream.ReceiveIntegerR(4);
// Get the crypt password salt if there is one
if (areq == AUTH_REQ_CRYPT)
{
byte[] rst = new byte[2];
rst[0] = (byte)pg_stream.ReceiveChar();
rst[1] = (byte)pg_stream.ReceiveChar();
salt = new String(rst, 0, 2);
DriverManager.println("Crypt salt=" + salt);
}
// Or get the md5 password salt if there is one
if (areq == AUTH_REQ_MD5)
{
byte[] rst = new byte[4];
rst[0] = (byte)pg_stream.ReceiveChar();
rst[1] = (byte)pg_stream.ReceiveChar();
rst[2] = (byte)pg_stream.ReceiveChar();
rst[3] = (byte)pg_stream.ReceiveChar();
salt = new String(rst, 0, 4);
DriverManager.println("MD5 salt=" + salt);
}
// now send the auth packet
switch (areq)
{
case AUTH_REQ_OK:
break;
case AUTH_REQ_KRB4:
DriverManager.println("postgresql: KRB4");
throw new PSQLException("postgresql.con.kerb4");
case AUTH_REQ_KRB5:
DriverManager.println("postgresql: KRB5");
throw new PSQLException("postgresql.con.kerb5");
case AUTH_REQ_PASSWORD:
DriverManager.println("postgresql: PASSWORD");
pg_stream.SendInteger(5 + PG_PASSWORD.length(), 4);
pg_stream.Send(PG_PASSWORD.getBytes());
pg_stream.SendInteger(0, 1);
pg_stream.flush();
break;
case AUTH_REQ_CRYPT:
DriverManager.println("postgresql: CRYPT");
String crypted = UnixCrypt.crypt(salt, PG_PASSWORD);
pg_stream.SendInteger(5 + crypted.length(), 4);
pg_stream.Send(crypted.getBytes());
pg_stream.SendInteger(0, 1);
pg_stream.flush();
break;
case AUTH_REQ_MD5:
DriverManager.println("postgresql: MD5");
byte[] digest = MD5Digest.encode(PG_USER, PG_PASSWORD, salt);
pg_stream.SendInteger(5 + digest.length, 4);
pg_stream.Send(digest);
pg_stream.SendInteger(0, 1);
pg_stream.flush();
break;
default:
throw new PSQLException("postgresql.con.auth", new Integer(areq));
}
break;
default:
throw new PSQLException("postgresql.con.authfail");
}
}
while (areq != AUTH_REQ_OK);
}
catch (IOException e)
{
throw new PSQLException("postgresql.con.failed", e);
}
// As of protocol version 2.0, we should now receive the cancellation key and the pid
int beresp = pg_stream.ReceiveChar();
switch (beresp)
{
case 'K':
pid = pg_stream.ReceiveIntegerR(4);
ckey = pg_stream.ReceiveIntegerR(4);
break;
case 'E':
throw new PSQLException("postgresql.con.backend", pg_stream.ReceiveString(encoding));
case 'N':
addWarning(pg_stream.ReceiveString(encoding));
break;
default:
throw new PSQLException("postgresql.con.setup");
}
// Expect ReadyForQuery packet
beresp = pg_stream.ReceiveChar();
switch (beresp)
{
case 'Z':
break;
case 'E':
throw new PSQLException("postgresql.con.backend", pg_stream.ReceiveString(encoding));
default:
throw new PSQLException("postgresql.con.setup");
}
// "pg_encoding_to_char(1)" will return 'EUC_JP' for a backend compiled with multibyte,
// otherwise it's hardcoded to 'SQL_ASCII'.
// If the backend doesn't know about multibyte we can't assume anything about the encoding
// used, so we denote this with 'UNKNOWN'.
//Note: begining with 7.2 we should be using pg_client_encoding() which
//is new in 7.2. However it isn't easy to conditionally call this new
//function, since we don't yet have the information as to what server
//version we are talking to. Thus we will continue to call
//getdatabaseencoding() until we drop support for 7.1 and older versions
//or until someone comes up with a conditional way to run one or
//the other function depending on server version that doesn't require
//two round trips to the server per connection
final String encodingQuery =
"case when pg_encoding_to_char(1) = 'SQL_ASCII' then 'UNKNOWN' else getdatabaseencoding() end";
// Set datestyle and fetch db encoding in a single call, to avoid making
// more than one round trip to the backend during connection startup.
java.sql.ResultSet resultSet =
ExecSQL("set datestyle to 'ISO'; select version(), " + encodingQuery + ";");
if (! resultSet.next())
{
throw new PSQLException("postgresql.con.failed", "failed getting backend encoding");
}
String version = resultSet.getString(1);
dbVersionNumber = extractVersionNumber(version);
String dbEncoding = resultSet.getString(2);
encoding = Encoding.getEncoding(dbEncoding, info.getProperty("charSet"));
// Initialise object handling
initObjectTypes();
// Mark the connection as ok, and cleanup
PG_STATUS = CONNECTION_OK;
}
// These methods used to be in the main Connection implementation. As they
// are common to all implementations (JDBC1 or 2), they are placed here.
// This should make it easy to maintain the two specifications.
/*
* This adds a warning to the warning chain.
* @param msg message to add
*/
public void addWarning(String msg)
{
DriverManager.println(msg);
// Add the warning to the chain
if (firstWarning != null)
firstWarning.setNextWarning(new SQLWarning(msg));
else
firstWarning = new SQLWarning(msg);
// Now check for some specific messages
// This is obsolete in 6.5, but I've left it in here so if we need to use this
// technique again, we'll know where to place it.
//
// This is generated by the SQL "show datestyle"
//if (msg.startsWith("NOTICE:") && msg.indexOf("DateStyle")>0) {
//// 13 is the length off "DateStyle is "
//msg = msg.substring(msg.indexOf("DateStyle is ")+13);
//
//for(int i=0;i<dateStyles.length;i+=2)
//if (msg.startsWith(dateStyles[i]))
//currentDateStyle=i+1; // this is the index of the format
//}
}
/*
* Send a query to the backend. Returns one of the ResultSet
* objects.
*
* <B>Note:</B> there does not seem to be any method currently
* in existance to return the update count.
*
* @param sql the SQL statement to be executed
* @return a ResultSet holding the results
* @exception SQLException if a database error occurs
*/
public java.sql.ResultSet ExecSQL(String sql) throws SQLException
{
return ExecSQL(sql, null);
}
/*
* Send a query to the backend. Returns one of the ResultSet
* objects.
*
* <B>Note:</B> there does not seem to be any method currently
* in existance to return the update count.
*
* @param sql the SQL statement to be executed
* @param stat The Statement associated with this query (may be null)
* @return a ResultSet holding the results
* @exception SQLException if a database error occurs
*/
public java.sql.ResultSet ExecSQL(String sql, java.sql.Statement stat) throws SQLException
{
return new QueryExecutor(sql, stat, pg_stream, this).execute();
}
/*
* In SQL, a result table can be retrieved through a cursor that
* is named. The current row of a result can be updated or deleted
* using a positioned update/delete statement that references the
* cursor name.
*
* We support one cursor per connection.
*
* setCursorName sets the cursor name.
*
* @param cursor the cursor name
* @exception SQLException if a database access error occurs
*/
public void setCursorName(String cursor) throws SQLException
{
this.cursor = cursor;
}
/*
* getCursorName gets the cursor name.
*
* @return the current cursor name
* @exception SQLException if a database access error occurs
*/
public String getCursorName() throws SQLException
{
return cursor;
}
/*
* We are required to bring back certain information by
* the DatabaseMetaData class. These functions do that.
*
* Method getURL() brings back the URL (good job we saved it)
*
* @return the url
* @exception SQLException just in case...
*/
public String getURL() throws SQLException
{
return this_url;
}
/*
* Method getUserName() brings back the User Name (again, we
* saved it)
*
* @return the user name
* @exception SQLException just in case...
*/
int lastMessage = 0;
public String getUserName() throws SQLException
{
return PG_USER;
}
/*
* Get the character encoding to use for this connection.
*/
public Encoding getEncoding() throws SQLException
{
return encoding;
}
/*
* This returns the Fastpath API for the current connection.
*
* <p><b>NOTE:</b> This is not part of JDBC, but allows access to
* functions on the org.postgresql backend itself.
*
* <p>It is primarily used by the LargeObject API
*
* <p>The best way to use this is as follows:
*
* <p><pre>
* import org.postgresql.fastpath.*;
* ...
* Fastpath fp = ((org.postgresql.Connection)myconn).getFastpathAPI();
* </pre>
*
* <p>where myconn is an open Connection to org.postgresql.
*
* @return Fastpath object allowing access to functions on the org.postgresql
* backend.
* @exception SQLException by Fastpath when initialising for first time
*/
public Fastpath getFastpathAPI() throws SQLException
{
if (fastpath == null)
fastpath = new Fastpath(this, pg_stream);
return fastpath;
}
// This holds a reference to the Fastpath API if already open
private Fastpath fastpath = null;
/*
* This returns the LargeObject API for the current connection.
*
* <p><b>NOTE:</b> This is not part of JDBC, but allows access to
* functions on the org.postgresql backend itself.
*
* <p>The best way to use this is as follows:
*
* <p><pre>
* import org.postgresql.largeobject.*;
* ...
* LargeObjectManager lo = ((org.postgresql.Connection)myconn).getLargeObjectAPI();
* </pre>
*
* <p>where myconn is an open Connection to org.postgresql.
*
* @return LargeObject object that implements the API
* @exception SQLException by LargeObject when initialising for first time
*/
public LargeObjectManager getLargeObjectAPI() throws SQLException
{
if (largeobject == null)
largeobject = new LargeObjectManager(this);
return largeobject;
}
// This holds a reference to the LargeObject API if already open
private LargeObjectManager largeobject = null;
/*
* This method is used internally to return an object based around
* org.postgresql's more unique data types.
*
* <p>It uses an internal Hashtable to get the handling class. If the
* type is not supported, then an instance of org.postgresql.util.PGobject
* is returned.
*
* You can use the getValue() or setValue() methods to handle the returned
* object. Custom objects can have their own methods.
*
* In 6.4, this is extended to use the org.postgresql.util.Serialize class to
* allow the Serialization of Java Objects into the database without using
* Blobs. Refer to that class for details on how this new feature works.
*
* @return PGobject for this type, and set to value
* @exception SQLException if value is not correct for this type
* @see org.postgresql.util.Serialize
*/
public Object getObject(String type, String value) throws SQLException
{
try
{
Object o = objectTypes.get(type);
// If o is null, then the type is unknown, so check to see if type
// is an actual table name. If it does, see if a Class is known that
// can handle it
if (o == null)
{
Serialize ser = new Serialize(this, type);
objectTypes.put(type, ser);
return ser.fetch(Integer.parseInt(value));
}
// If o is not null, and it is a String, then its a class name that
// extends PGobject.
//
// This is used to implement the org.postgresql unique types (like lseg,
// point, etc).
if (o instanceof String)
{
// 6.3 style extending PG_Object
PGobject obj = null;
obj = (PGobject)(Class.forName((String)o).newInstance());
obj.setType(type);
obj.setValue(value);
return (Object)obj;
}
else
{
// If it's an object, it should be an instance of our Serialize class
// If so, then call it's fetch method.
if (o instanceof Serialize)
return ((Serialize)o).fetch(Integer.parseInt(value));
}
}
catch (SQLException sx)
{
// rethrow the exception. Done because we capture any others next
sx.fillInStackTrace();
throw sx;
}
catch (Exception ex)
{
throw new PSQLException("postgresql.con.creobj", type, ex);
}
// should never be reached
return null;
}
/*
* This stores an object into the database. This method was
* deprecated in 7.2 bacause an OID can be larger than the java signed
* int returned by this method.
* @deprecated Replaced by storeObject() in 7.2
*/
public int putObject(Object o) throws SQLException
{
return (int) storeObject(o);
}
/*
* This stores an object into the database.
* @param o Object to store
* @return OID of the new rectord
* @exception SQLException if value is not correct for this type
* @see org.postgresql.util.Serialize
* @since 7.2
*/
public long storeObject(Object o) throws SQLException
{
try
{
String type = o.getClass().getName();
Object x = objectTypes.get(type);
// If x is null, then the type is unknown, so check to see if type
// is an actual table name. If it does, see if a Class is known that
// can handle it
if (x == null)
{
Serialize ser = new Serialize(this, type);
objectTypes.put(type, ser);
return ser.storeObject(o);
}
// If it's an object, it should be an instance of our Serialize class
// If so, then call it's fetch method.
if (x instanceof Serialize)
return ((Serialize)x).storeObject(o);
// Thow an exception because the type is unknown
throw new PSQLException("postgresql.con.strobj");
}
catch (SQLException sx)
{
// rethrow the exception. Done because we capture any others next
sx.fillInStackTrace();
throw sx;
}
catch (Exception ex)
{
throw new PSQLException("postgresql.con.strobjex", ex);
}
}
/*
* This allows client code to add a handler for one of org.postgresql's
* more unique data types.
*
* <p><b>NOTE:</b> This is not part of JDBC, but an extension.
*
* <p>The best way to use this is as follows:
*
* <p><pre>
* ...
* ((org.postgresql.Connection)myconn).addDataType("mytype","my.class.name");
* ...
* </pre>
*
* <p>where myconn is an open Connection to org.postgresql.
*
* <p>The handling class must extend org.postgresql.util.PGobject
*
* @see org.postgresql.util.PGobject
*/
public void addDataType(String type, String name)
{
objectTypes.put(type, name);
}
// This holds the available types
private Hashtable objectTypes = new Hashtable();
// This array contains the types that are supported as standard.
//
// The first entry is the types name on the database, the second
// the full class name of the handling class.
//
private static final String defaultObjectTypes[][] = {
{"box", "org.postgresql.geometric.PGbox"},
{"circle", "org.postgresql.geometric.PGcircle"},
{"line", "org.postgresql.geometric.PGline"},
{"lseg", "org.postgresql.geometric.PGlseg"},
{"path", "org.postgresql.geometric.PGpath"},
{"point", "org.postgresql.geometric.PGpoint"},
{"polygon", "org.postgresql.geometric.PGpolygon"},
{"money", "org.postgresql.util.PGmoney"}
};
// This initialises the objectTypes hashtable
private void initObjectTypes()
{
for (int i = 0;i < defaultObjectTypes.length;i++)
objectTypes.put(defaultObjectTypes[i][0], defaultObjectTypes[i][1]);
}
// These are required by other common classes
public abstract java.sql.Statement createStatement() throws SQLException;
/*
* This returns a resultset. It must be overridden, so that the correct
* version (from jdbc1 or jdbc2) are returned.
*/
public abstract java.sql.ResultSet getResultSet(org.postgresql.Connection conn, java.sql.Statement stat, Field[] fields, Vector tuples, String status, int updateCount, long insertOID, boolean binaryCursor) throws SQLException;
/*
* In some cases, it is desirable to immediately release a Connection's
* database and JDBC resources instead of waiting for them to be
* automatically released (cant think why off the top of my head)
*
* <B>Note:</B> A Connection is automatically closed when it is
* garbage collected. Certain fatal errors also result in a closed
* connection.
*
* @exception SQLException if a database access error occurs
*/
public void close() throws SQLException
{
if (pg_stream != null)
{
try
{
pg_stream.SendChar('X');
pg_stream.flush();
pg_stream.close();
}
catch (IOException e)
{}
pg_stream = null;
}
}
/*
* A driver may convert the JDBC sql grammar into its system's
* native SQL grammar prior to sending it; nativeSQL returns the
* native form of the statement that the driver would have sent.
*
* @param sql a SQL statement that may contain one or more '?'
* parameter placeholders
* @return the native form of this statement
* @exception SQLException if a database access error occurs
*/
public String nativeSQL(String sql) throws SQLException
{
return sql;
}
/*
* The first warning reported by calls on this Connection is
* returned.
*
* <B>Note:</B> Sebsequent warnings will be changed to this
* SQLWarning
*
* @return the first SQLWarning or null
* @exception SQLException if a database access error occurs
*/
public SQLWarning getWarnings() throws SQLException
{
return firstWarning;
}
/*
* After this call, getWarnings returns null until a new warning
* is reported for this connection.
*
* @exception SQLException if a database access error occurs
*/
public void clearWarnings() throws SQLException
{
firstWarning = null;
}
/*
* You can put a connection in read-only mode as a hunt to enable
* database optimizations
*
* <B>Note:</B> setReadOnly cannot be called while in the middle
* of a transaction
*
* @param readOnly - true enables read-only mode; false disables it
* @exception SQLException if a database access error occurs
*/
public void setReadOnly(boolean readOnly) throws SQLException
{
this.readOnly = readOnly;
}
/*
* Tests to see if the connection is in Read Only Mode. Note that
* we cannot really put the database in read only mode, but we pretend
* we can by returning the value of the readOnly flag
*
* @return true if the connection is read only
* @exception SQLException if a database access error occurs
*/
public boolean isReadOnly() throws SQLException
{
return readOnly;
}
/*
* If a connection is in auto-commit mode, than all its SQL
* statements will be executed and committed as individual
* transactions. Otherwise, its SQL statements are grouped
* into transactions that are terminated by either commit()
* or rollback(). By default, new connections are in auto-
* commit mode. The commit occurs when the statement completes
* or the next execute occurs, whichever comes first. In the
* case of statements returning a ResultSet, the statement
* completes when the last row of the ResultSet has been retrieved
* or the ResultSet has been closed. In advanced cases, a single
* statement may return multiple results as well as output parameter
* values. Here the commit occurs when all results and output param
* values have been retrieved.
*
* @param autoCommit - true enables auto-commit; false disables it
* @exception SQLException if a database access error occurs
*/
public void setAutoCommit(boolean autoCommit) throws SQLException
{
if (this.autoCommit == autoCommit)
return;
if (autoCommit)
ExecSQL("end");
else
{
if (haveMinimumServerVersion("7.1"))
{
ExecSQL("begin;" + getIsolationLevelSQL());
}
else
{
ExecSQL("begin");
ExecSQL(getIsolationLevelSQL());
}
}
this.autoCommit = autoCommit;
}
/*
* gets the current auto-commit state
*
* @return Current state of the auto-commit mode
* @exception SQLException (why?)
* @see setAutoCommit
*/
public boolean getAutoCommit() throws SQLException
{
return this.autoCommit;
}
/*
* The method commit() makes all changes made since the previous
* commit/rollback permanent and releases any database locks currently
* held by the Connection. This method should only be used when
* auto-commit has been disabled. (If autoCommit == true, then we
* just return anyhow)
*
* @exception SQLException if a database access error occurs
* @see setAutoCommit
*/
public void commit() throws SQLException
{
if (autoCommit)
return;
if (haveMinimumServerVersion("7.1"))
{
ExecSQL("commit;begin;" + getIsolationLevelSQL());
}
else
{
ExecSQL("commit");
ExecSQL("begin");
ExecSQL(getIsolationLevelSQL());
}
}
/*
* The method rollback() drops all changes made since the previous
* commit/rollback and releases any database locks currently held by
* the Connection.
*
* @exception SQLException if a database access error occurs
* @see commit
*/
public void rollback() throws SQLException
{
if (autoCommit)
return;
if (haveMinimumServerVersion("7.1"))
{
ExecSQL("rollback; begin;" + getIsolationLevelSQL());
}
else
{
ExecSQL("rollback");
ExecSQL("begin");
ExecSQL(getIsolationLevelSQL());
}
}
/*
* Get this Connection's current transaction isolation mode.
*
* @return the current TRANSACTION_* mode value
* @exception SQLException if a database access error occurs
*/
public int getTransactionIsolation() throws SQLException
{
clearWarnings();
ExecSQL("show xactisolevel");
SQLWarning warning = getWarnings();
if (warning != null)
{
String message = warning.getMessage();
clearWarnings();
if (message.indexOf("READ COMMITTED") != -1)
return java.sql.Connection.TRANSACTION_READ_COMMITTED;
else if (message.indexOf("READ UNCOMMITTED") != -1)
return java.sql.Connection.TRANSACTION_READ_UNCOMMITTED;
else if (message.indexOf("REPEATABLE READ") != -1)
return java.sql.Connection.TRANSACTION_REPEATABLE_READ;
else if (message.indexOf("SERIALIZABLE") != -1)
return java.sql.Connection.TRANSACTION_SERIALIZABLE;
}
return java.sql.Connection.TRANSACTION_READ_COMMITTED;
}
/*
* You can call this method to try to change the transaction
* isolation level using one of the TRANSACTION_* values.
*
* <B>Note:</B> setTransactionIsolation cannot be called while
* in the middle of a transaction
*
* @param level one of the TRANSACTION_* isolation values with
* the exception of TRANSACTION_NONE; some databases may
* not support other values
* @exception SQLException if a database access error occurs
* @see java.sql.DatabaseMetaData#supportsTransactionIsolationLevel
*/
public void setTransactionIsolation(int level) throws SQLException
{
//In 7.1 and later versions of the server it is possible using
//the "set session" command to set this once for all future txns
//however in 7.0 and prior versions it is necessary to set it in
//each transaction, thus adding complexity below.
//When we decide to drop support for servers older than 7.1
//this can be simplified
isolationLevel = level;
String isolationLevelSQL;
if (!haveMinimumServerVersion("7.1"))
{
isolationLevelSQL = getIsolationLevelSQL();
}
else
{
isolationLevelSQL = "SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL ";
switch (isolationLevel)
{
case java.sql.Connection.TRANSACTION_READ_COMMITTED:
isolationLevelSQL += "READ COMMITTED";
break;
case java.sql.Connection.TRANSACTION_SERIALIZABLE:
isolationLevelSQL += "SERIALIZABLE";
break;
default:
throw new PSQLException("postgresql.con.isolevel",
new Integer(isolationLevel));
}
}
ExecSQL(isolationLevelSQL);
}
/*
* Helper method used by setTransactionIsolation(), commit(), rollback()
* and setAutoCommit(). This returns the SQL string needed to
* set the isolation level for a transaction. In 7.1 and later it
* is possible to set a default isolation level that applies to all
* future transactions, this method is only necesary for 7.0 and older
* servers, and should be removed when support for these older
* servers are dropped
*/
protected String getIsolationLevelSQL() throws SQLException
{
//7.1 and higher servers have a default specified so
//no additional SQL is required to set the isolation level
if (haveMinimumServerVersion("7.1"))
{
return "";
}
StringBuffer sb = new StringBuffer("SET TRANSACTION ISOLATION LEVEL");
switch (isolationLevel)
{
case java.sql.Connection.TRANSACTION_READ_COMMITTED:
sb.append(" READ COMMITTED");
break;
case java.sql.Connection.TRANSACTION_SERIALIZABLE:
sb.append(" SERIALIZABLE");
break;
default:
throw new PSQLException("postgresql.con.isolevel", new Integer(isolationLevel));
}
return sb.toString();
}
/*
* A sub-space of this Connection's database may be selected by
* setting a catalog name. If the driver does not support catalogs,
* it will silently ignore this request
*
* @exception SQLException if a database access error occurs
*/
public void setCatalog(String catalog) throws SQLException
{
//no-op
}
/*
* Return the connections current catalog name, or null if no
* catalog name is set, or we dont support catalogs.
*
* @return the current catalog name or null
* @exception SQLException if a database access error occurs
*/
public String getCatalog() throws SQLException
{
return PG_DATABASE;
}
/*
* Overides finalize(). If called, it closes the connection.
*
* This was done at the request of Rachel Greenham
* <rachel@enlarion.demon.co.uk> who hit a problem where multiple
* clients didn't close the connection, and once a fortnight enough
* clients were open to kill the org.postgres server.
*/
public void finalize() throws Throwable
{
close();
}
private static String extractVersionNumber(String fullVersionString)
{
StringTokenizer versionParts = new StringTokenizer(fullVersionString);
versionParts.nextToken(); /* "PostgreSQL" */
return versionParts.nextToken(); /* "X.Y.Z" */
}
/*
* Get server version number
*/
public String getDBVersionNumber()
{
return dbVersionNumber;
}
public boolean haveMinimumServerVersion(String ver) throws SQLException
{
return (getDBVersionNumber().compareTo(ver) >= 0);
}
/*
* This method returns true if the compatible level set in the connection
* (which can be passed into the connection or specified in the URL)
* is at least the value passed to this method. This is used to toggle
* between different functionality as it changes across different releases
* of the jdbc driver code. The values here are versions of the jdbc client
* and not server versions. For example in 7.1 get/setBytes worked on
* LargeObject values, in 7.2 these methods were changed to work on bytea
* values. This change in functionality could be disabled by setting the
* "compatible" level to be 7.1, in which case the driver will revert to
* the 7.1 functionality.
*/
public boolean haveMinimumCompatibleVersion(String ver) throws SQLException
{
return (compatible.compareTo(ver) >= 0);
}
/*
* This returns the java.sql.Types type for a PG type oid
*
* @param oid PostgreSQL type oid
* @return the java.sql.Types type
* @exception SQLException if a database access error occurs
*/
public int getSQLType(int oid) throws SQLException
{
Integer sqlType = (Integer)sqlTypeCache.get(new Integer(oid));
// it's not in the cache, so perform a query, and add the result to the cache
if (sqlType == null)
{
ResultSet result = (org.postgresql.ResultSet)ExecSQL("select typname from pg_type where oid = " + oid);
if (result.getColumnCount() != 1 || result.getTupleCount() != 1)
throw new PSQLException("postgresql.unexpected");
result.next();
String pgType = result.getString(1);
Integer iOid = new Integer(oid);
sqlType = new Integer(getSQLType(result.getString(1)));
sqlTypeCache.put(iOid, sqlType);
pgTypeCache.put(iOid, pgType);
result.close();
}
return sqlType.intValue();
}
/*
* This returns the java.sql.Types type for a PG type
*
* @param pgTypeName PostgreSQL type name
* @return the java.sql.Types type
*/
public abstract int getSQLType(String pgTypeName);
/*
* This returns the oid for a given PG data type
* @param typeName PostgreSQL type name
* @return PostgreSQL oid value for a field of this type
*/
public int getOID(String typeName) throws SQLException
{
int oid = -1;
if (typeName != null)
{
Integer oidValue = (Integer) typeOidCache.get(typeName);
if (oidValue != null)
{
oid = oidValue.intValue();
}
else
{
// it's not in the cache, so perform a query, and add the result to the cache
ResultSet result = (org.postgresql.ResultSet)ExecSQL("select oid from pg_type where typname='"
+ typeName + "'");
if (result.getColumnCount() != 1 || result.getTupleCount() != 1)
throw new PSQLException("postgresql.unexpected");
result.next();
oid = Integer.parseInt(result.getString(1));
typeOidCache.put(typeName, new Integer(oid));
result.close();
}
}
return oid;
}
/*
* We also need to get the PG type name as returned by the back end.
*
* @return the String representation of the type of this field
* @exception SQLException if a database access error occurs
*/
public String getPGType(int oid) throws SQLException
{
String pgType = (String) pgTypeCache.get(new Integer(oid));
if (pgType == null)
{
getSQLType(oid);
pgType = (String) pgTypeCache.get(new Integer(oid));
}
return pgType;
}
}
package org.postgresql;
import java.io.*;
import java.net.*;
import java.sql.*;
import java.util.*;
import org.postgresql.Field;
import org.postgresql.fastpath.*;
import org.postgresql.largeobject.*;
import org.postgresql.util.*;
import org.postgresql.core.*;
/*
* $Id: Connection.java,v 1.44 2002/03/21 02:39:06 davec Exp $
*
* This abstract class is used by org.postgresql.Driver to open either the JDBC1 or
* JDBC2 versions of the Connection class.
*
*/
public abstract class Connection
{
// This is the network stream associated with this connection
public PG_Stream pg_stream;
private String PG_HOST;
private int PG_PORT;
private String PG_USER;
private String PG_DATABASE;
private boolean PG_STATUS;
private String compatible;
/*
* The encoding to use for this connection.
*/
private Encoding encoding = Encoding.defaultEncoding();
private String dbVersionNumber;
public boolean CONNECTION_OK = true;
public boolean CONNECTION_BAD = false;
public boolean autoCommit = true;
public boolean readOnly = false;
public Driver this_driver;
private String this_url;
private String cursor = null; // The positioned update cursor name
// These are new for v6.3, they determine the current protocol versions
// supported by this version of the driver. They are defined in
// src/include/libpq/pqcomm.h
protected static final int PG_PROTOCOL_LATEST_MAJOR = 2;
protected static final int PG_PROTOCOL_LATEST_MINOR = 0;
private static final int AUTH_REQ_OK = 0;
private static final int AUTH_REQ_KRB4 = 1;
private static final int AUTH_REQ_KRB5 = 2;
private static final int AUTH_REQ_PASSWORD = 3;
private static final int AUTH_REQ_CRYPT = 4;
private static final int AUTH_REQ_MD5 = 5;
public final static int PGASYNC_IDLE = 0; /* nothing's happening, dude */
public final static int PGASYNC_BUSY = 1; /* query in progress */
public final static int PGASYNC_READY = 2; /* result ready for PQgetResult */
// These are used to cache oids, PGTypes and SQLTypes
private static Hashtable sqlTypeCache = new Hashtable(); // oid -> SQLType
private static Hashtable pgTypeCache = new Hashtable(); // oid -> PGType
private static Hashtable typeOidCache = new Hashtable(); //PGType -> oid
// Now handle notices as warnings, so things like "show" now work
public SQLWarning firstWarning = null;
/*
* Cache of the current isolation level
*/
private int isolationLevel = java.sql.Connection.TRANSACTION_READ_COMMITTED;
// The PID an cancellation key we get from the backend process
public int pid;
public int ckey;
public int asyncStatus = PGASYNC_READY;
/*
* This is called by Class.forName() from within org.postgresql.Driver
*/
public Connection()
{}
public void cancelQuery() throws SQLException
{
PG_Stream cancelStream = null;
try {
cancelStream = new PG_Stream(PG_HOST, PG_PORT);
} catch (ConnectException cex) {
// Added by Peter Mount <peter@retep.org.uk>
// ConnectException is thrown when the connection cannot be made.
// we trap this an return a more meaningful message for the end user
throw new PSQLException ("postgresql.con.refused");
} catch (IOException e) {
throw new PSQLException ("postgresql.con.failed",e);
}
// Now we need to construct and send a cancel packet
try {
cancelStream.SendInteger(16, 4);
cancelStream.SendInteger(80877102, 4);
cancelStream.SendInteger(pid, 4);
cancelStream.SendInteger(ckey, 4);
cancelStream.flush();
}
catch(IOException e) {
throw new PSQLException("postgresql.con.failed",e);
}
finally {
try {
if(cancelStream != null)
cancelStream.close();
}
catch(IOException e) {} // Ignore
}
}
/*
* This method actually opens the connection. It is called by Driver.
*
* @param host the hostname of the database back end
* @param port the port number of the postmaster process
* @param info a Properties[] thing of the user and password
* @param database the database to connect to
* @param u the URL of the connection
* @param d the Driver instantation of the connection
* @return a valid connection profile
* @exception SQLException if a database access error occurs
*/
protected void openConnection(String host, int port, Properties info, String database, String url, Driver d) throws SQLException
{
firstWarning = null;
// Throw an exception if the user or password properties are missing
// This occasionally occurs when the client uses the properties version
// of getConnection(), and is a common question on the email lists
if (info.getProperty("user") == null)
throw new PSQLException("postgresql.con.user");
this_driver = d;
this_url = url;
PG_DATABASE = database;
PG_USER = info.getProperty("user");
String password = info.getProperty("password", "");
PG_PORT = port;
PG_HOST = host;
PG_STATUS = CONNECTION_BAD;
if (info.getProperty("compatible") == null)
{
compatible = d.getMajorVersion() + "." + d.getMinorVersion();
}
else
{
compatible = info.getProperty("compatible");
}
// Now make the initial connection
try
{
pg_stream = new PG_Stream(host, port);
}
catch (ConnectException cex)
{
// Added by Peter Mount <peter@retep.org.uk>
// ConnectException is thrown when the connection cannot be made.
// we trap this an return a more meaningful message for the end user
throw new PSQLException ("postgresql.con.refused");
}
catch (IOException e)
{
throw new PSQLException ("postgresql.con.failed", e);
}
// Now we need to construct and send a startup packet
try
{
new StartupPacket(PG_PROTOCOL_LATEST_MAJOR,
PG_PROTOCOL_LATEST_MINOR,
PG_USER,
database).writeTo(pg_stream);
// now flush the startup packets to the backend
pg_stream.flush();
// Now get the response from the backend, either an error message
// or an authentication request
int areq = -1; // must have a value here
do
{
int beresp = pg_stream.ReceiveChar();
String salt = null;
switch (beresp)
{
case 'E':
// An error occured, so pass the error message to the
// user.
//
// The most common one to be thrown here is:
// "User authentication failed"
//
throw new PSQLException("postgresql.con.misc", pg_stream.ReceiveString(encoding));
case 'R':
// Get the type of request
areq = pg_stream.ReceiveIntegerR(4);
// Get the crypt password salt if there is one
if (areq == AUTH_REQ_CRYPT)
{
byte[] rst = new byte[2];
rst[0] = (byte)pg_stream.ReceiveChar();
rst[1] = (byte)pg_stream.ReceiveChar();
salt = new String(rst, 0, 2);
DriverManager.println("Crypt salt=" + salt);
}
// Or get the md5 password salt if there is one
if (areq == AUTH_REQ_MD5)
{
byte[] rst = new byte[4];
rst[0] = (byte)pg_stream.ReceiveChar();
rst[1] = (byte)pg_stream.ReceiveChar();
rst[2] = (byte)pg_stream.ReceiveChar();
rst[3] = (byte)pg_stream.ReceiveChar();
salt = new String(rst, 0, 4);
DriverManager.println("MD5 salt=" + salt);
}
// now send the auth packet
switch (areq)
{
case AUTH_REQ_OK:
break;
case AUTH_REQ_KRB4:
DriverManager.println("postgresql: KRB4");
throw new PSQLException("postgresql.con.kerb4");
case AUTH_REQ_KRB5:
DriverManager.println("postgresql: KRB5");
throw new PSQLException("postgresql.con.kerb5");
case AUTH_REQ_PASSWORD:
DriverManager.println("postgresql: PASSWORD");
pg_stream.SendInteger(5 + password.length(), 4);
pg_stream.Send(password.getBytes());
pg_stream.SendInteger(0, 1);
pg_stream.flush();
break;
case AUTH_REQ_CRYPT:
DriverManager.println("postgresql: CRYPT");
String crypted = UnixCrypt.crypt(salt, password);
pg_stream.SendInteger(5 + crypted.length(), 4);
pg_stream.Send(crypted.getBytes());
pg_stream.SendInteger(0, 1);
pg_stream.flush();
break;
case AUTH_REQ_MD5:
DriverManager.println("postgresql: MD5");
byte[] digest = MD5Digest.encode(PG_USER, password, salt);
pg_stream.SendInteger(5 + digest.length, 4);
pg_stream.Send(digest);
pg_stream.SendInteger(0, 1);
pg_stream.flush();
break;
default:
throw new PSQLException("postgresql.con.auth", new Integer(areq));
}
break;
default:
throw new PSQLException("postgresql.con.authfail");
}
}
while (areq != AUTH_REQ_OK);
}
catch (IOException e)
{
throw new PSQLException("postgresql.con.failed", e);
}
// As of protocol version 2.0, we should now receive the cancellation key and the pid
int beresp = pg_stream.ReceiveChar();
switch (beresp)
{
case 'K':
pid = pg_stream.ReceiveIntegerR(4);
ckey = pg_stream.ReceiveIntegerR(4);
break;
case 'E':
throw new PSQLException("postgresql.con.backend", pg_stream.ReceiveString(encoding));
case 'N':
addWarning(pg_stream.ReceiveString(encoding));
break;
default:
throw new PSQLException("postgresql.con.setup");
}
// Expect ReadyForQuery packet
beresp = pg_stream.ReceiveChar();
switch (beresp)
{
case 'Z':
break;
case 'E':
throw new PSQLException("postgresql.con.backend", pg_stream.ReceiveString(encoding));
default:
throw new PSQLException("postgresql.con.setup");
}
// "pg_encoding_to_char(1)" will return 'EUC_JP' for a backend compiled with multibyte,
// otherwise it's hardcoded to 'SQL_ASCII'.
// If the backend doesn't know about multibyte we can't assume anything about the encoding
// used, so we denote this with 'UNKNOWN'.
//Note: begining with 7.2 we should be using pg_client_encoding() which
//is new in 7.2. However it isn't easy to conditionally call this new
//function, since we don't yet have the information as to what server
//version we are talking to. Thus we will continue to call
//getdatabaseencoding() until we drop support for 7.1 and older versions
//or until someone comes up with a conditional way to run one or
//the other function depending on server version that doesn't require
//two round trips to the server per connection
final String encodingQuery =
"case when pg_encoding_to_char(1) = 'SQL_ASCII' then 'UNKNOWN' else getdatabaseencoding() end";
// Set datestyle and fetch db encoding in a single call, to avoid making
// more than one round trip to the backend during connection startup.
java.sql.ResultSet resultSet =
ExecSQL("set datestyle to 'ISO'; select version(), " + encodingQuery + ";");
if (! resultSet.next())
{
throw new PSQLException("postgresql.con.failed", "failed getting backend encoding");
}
String version = resultSet.getString(1);
dbVersionNumber = extractVersionNumber(version);
String dbEncoding = resultSet.getString(2);
encoding = Encoding.getEncoding(dbEncoding, info.getProperty("charSet"));
// Initialise object handling
initObjectTypes();
// Mark the connection as ok, and cleanup
PG_STATUS = CONNECTION_OK;
}
// These methods used to be in the main Connection implementation. As they
// are common to all implementations (JDBC1 or 2), they are placed here.
// This should make it easy to maintain the two specifications.
/*
* This adds a warning to the warning chain.
* @param msg message to add
*/
public void addWarning(String msg)
{
DriverManager.println(msg);
// Add the warning to the chain
if (firstWarning != null)
firstWarning.setNextWarning(new SQLWarning(msg));
else
firstWarning = new SQLWarning(msg);
// Now check for some specific messages
// This is obsolete in 6.5, but I've left it in here so if we need to use this
// technique again, we'll know where to place it.
//
// This is generated by the SQL "show datestyle"
//if (msg.startsWith("NOTICE:") && msg.indexOf("DateStyle")>0) {
//// 13 is the length off "DateStyle is "
//msg = msg.substring(msg.indexOf("DateStyle is ")+13);
//
//for(int i=0;i<dateStyles.length;i+=2)
//if (msg.startsWith(dateStyles[i]))
//currentDateStyle=i+1; // this is the index of the format
//}
}
/*
* Send a query to the backend. Returns one of the ResultSet
* objects.
*
* <B>Note:</B> there does not seem to be any method currently
* in existance to return the update count.
*
* @param sql the SQL statement to be executed
* @return a ResultSet holding the results
* @exception SQLException if a database error occurs
*/
public java.sql.ResultSet ExecSQL(String sql) throws SQLException
{
return ExecSQL(sql, null);
}
/*
* Send a query to the backend. Returns one of the ResultSet
* objects.
*
* <B>Note:</B> there does not seem to be any method currently
* in existance to return the update count.
*
* @param sql the SQL statement to be executed
* @param stat The Statement associated with this query (may be null)
* @return a ResultSet holding the results
* @exception SQLException if a database error occurs
*/
public java.sql.ResultSet ExecSQL(String sql, java.sql.Statement stat) throws SQLException
{
return new QueryExecutor2(sql, stat, pg_stream, this).execute();
}
/*
* In SQL, a result table can be retrieved through a cursor that
* is named. The current row of a result can be updated or deleted
* using a positioned update/delete statement that references the
* cursor name.
*
* We support one cursor per connection.
*
* setCursorName sets the cursor name.
*
* @param cursor the cursor name
* @exception SQLException if a database access error occurs
*/
public void setCursorName(String cursor) throws SQLException
{
this.cursor = cursor;
}
/*
* getCursorName gets the cursor name.
*
* @return the current cursor name
* @exception SQLException if a database access error occurs
*/
public String getCursorName() throws SQLException
{
return cursor;
}
/*
* We are required to bring back certain information by
* the DatabaseMetaData class. These functions do that.
*
* Method getURL() brings back the URL (good job we saved it)
*
* @return the url
* @exception SQLException just in case...
*/
public String getURL() throws SQLException
{
return this_url;
}
/*
* Method getUserName() brings back the User Name (again, we
* saved it)
*
* @return the user name
* @exception SQLException just in case...
*/
int lastMessage = 0;
public String getUserName() throws SQLException
{
return PG_USER;
}
/*
* Get the character encoding to use for this connection.
*/
public Encoding getEncoding() throws SQLException
{
return encoding;
}
/*
* This returns the Fastpath API for the current connection.
*
* <p><b>NOTE:</b> This is not part of JDBC, but allows access to
* functions on the org.postgresql backend itself.
*
* <p>It is primarily used by the LargeObject API
*
* <p>The best way to use this is as follows:
*
* <p><pre>
* import org.postgresql.fastpath.*;
* ...
* Fastpath fp = ((org.postgresql.Connection)myconn).getFastpathAPI();
* </pre>
*
* <p>where myconn is an open Connection to org.postgresql.
*
* @return Fastpath object allowing access to functions on the org.postgresql
* backend.
* @exception SQLException by Fastpath when initialising for first time
*/
public Fastpath getFastpathAPI() throws SQLException
{
if (fastpath == null)
fastpath = new Fastpath(this, pg_stream);
return fastpath;
}
// This holds a reference to the Fastpath API if already open
private Fastpath fastpath = null;
/*
* This returns the LargeObject API for the current connection.
*
* <p><b>NOTE:</b> This is not part of JDBC, but allows access to
* functions on the org.postgresql backend itself.
*
* <p>The best way to use this is as follows:
*
* <p><pre>
* import org.postgresql.largeobject.*;
* ...
* LargeObjectManager lo = ((org.postgresql.Connection)myconn).getLargeObjectAPI();
* </pre>
*
* <p>where myconn is an open Connection to org.postgresql.
*
* @return LargeObject object that implements the API
* @exception SQLException by LargeObject when initialising for first time
*/
public LargeObjectManager getLargeObjectAPI() throws SQLException
{
if (largeobject == null)
largeobject = new LargeObjectManager(this);
return largeobject;
}
// This holds a reference to the LargeObject API if already open
private LargeObjectManager largeobject = null;
/*
* This method is used internally to return an object based around
* org.postgresql's more unique data types.
*
* <p>It uses an internal Hashtable to get the handling class. If the
* type is not supported, then an instance of org.postgresql.util.PGobject
* is returned.
*
* You can use the getValue() or setValue() methods to handle the returned
* object. Custom objects can have their own methods.
*
* In 6.4, this is extended to use the org.postgresql.util.Serialize class to
* allow the Serialization of Java Objects into the database without using
* Blobs. Refer to that class for details on how this new feature works.
*
* @return PGobject for this type, and set to value
* @exception SQLException if value is not correct for this type
* @see org.postgresql.util.Serialize
*/
public Object getObject(String type, String value) throws SQLException
{
try
{
Object o = objectTypes.get(type);
// If o is null, then the type is unknown, so check to see if type
// is an actual table name. If it does, see if a Class is known that
// can handle it
if (o == null)
{
Serialize ser = new Serialize(this, type);
objectTypes.put(type, ser);
return ser.fetch(Integer.parseInt(value));
}
// If o is not null, and it is a String, then its a class name that
// extends PGobject.
//
// This is used to implement the org.postgresql unique types (like lseg,
// point, etc).
if (o instanceof String)
{
// 6.3 style extending PG_Object
PGobject obj = null;
obj = (PGobject)(Class.forName((String)o).newInstance());
obj.setType(type);
obj.setValue(value);
return (Object)obj;
}
else
{
// If it's an object, it should be an instance of our Serialize class
// If so, then call it's fetch method.
if (o instanceof Serialize)
return ((Serialize)o).fetch(Integer.parseInt(value));
}
}
catch (SQLException sx)
{
// rethrow the exception. Done because we capture any others next
sx.fillInStackTrace();
throw sx;
}
catch (Exception ex)
{
throw new PSQLException("postgresql.con.creobj", type, ex);
}
// should never be reached
return null;
}
/*
* This stores an object into the database. This method was
* deprecated in 7.2 bacause an OID can be larger than the java signed
* int returned by this method.
* @deprecated Replaced by storeObject() in 7.2
*/
public int putObject(Object o) throws SQLException
{
return (int) storeObject(o);
}
/*
* This stores an object into the database.
* @param o Object to store
* @return OID of the new rectord
* @exception SQLException if value is not correct for this type
* @see org.postgresql.util.Serialize
* @since 7.2
*/
public long storeObject(Object o) throws SQLException
{
try
{
String type = o.getClass().getName();
Object x = objectTypes.get(type);
// If x is null, then the type is unknown, so check to see if type
// is an actual table name. If it does, see if a Class is known that
// can handle it
if (x == null)
{
Serialize ser = new Serialize(this, type);
objectTypes.put(type, ser);
return ser.storeObject(o);
}
// If it's an object, it should be an instance of our Serialize class
// If so, then call it's fetch method.
if (x instanceof Serialize)
return ((Serialize)x).storeObject(o);
// Thow an exception because the type is unknown
throw new PSQLException("postgresql.con.strobj");
}
catch (SQLException sx)
{
// rethrow the exception. Done because we capture any others next
sx.fillInStackTrace();
throw sx;
}
catch (Exception ex)
{
throw new PSQLException("postgresql.con.strobjex", ex);
}
}
/*
* This allows client code to add a handler for one of org.postgresql's
* more unique data types.
*
* <p><b>NOTE:</b> This is not part of JDBC, but an extension.
*
* <p>The best way to use this is as follows:
*
* <p><pre>
* ...
* ((org.postgresql.Connection)myconn).addDataType("mytype","my.class.name");
* ...
* </pre>
*
* <p>where myconn is an open Connection to org.postgresql.
*
* <p>The handling class must extend org.postgresql.util.PGobject
*
* @see org.postgresql.util.PGobject
*/
public void addDataType(String type, String name)
{
objectTypes.put(type, name);
}
// This holds the available types
private Hashtable objectTypes = new Hashtable();
// This array contains the types that are supported as standard.
//
// The first entry is the types name on the database, the second
// the full class name of the handling class.
//
private static final String defaultObjectTypes[][] = {
{"box", "org.postgresql.geometric.PGbox"},
{"circle", "org.postgresql.geometric.PGcircle"},
{"line", "org.postgresql.geometric.PGline"},
{"lseg", "org.postgresql.geometric.PGlseg"},
{"path", "org.postgresql.geometric.PGpath"},
{"point", "org.postgresql.geometric.PGpoint"},
{"polygon", "org.postgresql.geometric.PGpolygon"},
{"money", "org.postgresql.util.PGmoney"}
};
// This initialises the objectTypes hashtable
private void initObjectTypes()
{
for (int i = 0;i < defaultObjectTypes.length;i++)
objectTypes.put(defaultObjectTypes[i][0], defaultObjectTypes[i][1]);
}
// These are required by other common classes
public abstract java.sql.Statement createStatement() throws SQLException;
/*
* This returns a resultset. It must be overridden, so that the correct
* version (from jdbc1 or jdbc2) are returned.
*/
public abstract java.sql.ResultSet getResultSet(org.postgresql.Connection conn, java.sql.Statement stat, Field[] fields, Vector tuples, String status, int updateCount, long insertOID, boolean binaryCursor) throws SQLException;
/*
* In some cases, it is desirable to immediately release a Connection's
* database and JDBC resources instead of waiting for them to be
* automatically released (cant think why off the top of my head)
*
* <B>Note:</B> A Connection is automatically closed when it is
* garbage collected. Certain fatal errors also result in a closed
* connection.
*
* @exception SQLException if a database access error occurs
*/
public void close() throws SQLException
{
if (pg_stream != null)
{
try
{
pg_stream.SendChar('X');
pg_stream.flush();
pg_stream.close();
}
catch (IOException e)
{}
pg_stream = null;
}
}
/*
* A driver may convert the JDBC sql grammar into its system's
* native SQL grammar prior to sending it; nativeSQL returns the
* native form of the statement that the driver would have sent.
*
* @param sql a SQL statement that may contain one or more '?'
* parameter placeholders
* @return the native form of this statement
* @exception SQLException if a database access error occurs
*/
public String nativeSQL(String sql) throws SQLException
{
return sql;
}
/*
* The first warning reported by calls on this Connection is
* returned.
*
* <B>Note:</B> Sebsequent warnings will be changed to this
* SQLWarning
*
* @return the first SQLWarning or null
* @exception SQLException if a database access error occurs
*/
public SQLWarning getWarnings() throws SQLException
{
return firstWarning;
}
/*
* After this call, getWarnings returns null until a new warning
* is reported for this connection.
*
* @exception SQLException if a database access error occurs
*/
public void clearWarnings() throws SQLException
{
firstWarning = null;
}
/*
* You can put a connection in read-only mode as a hunt to enable
* database optimizations
*
* <B>Note:</B> setReadOnly cannot be called while in the middle
* of a transaction
*
* @param readOnly - true enables read-only mode; false disables it
* @exception SQLException if a database access error occurs
*/
public void setReadOnly(boolean readOnly) throws SQLException
{
this.readOnly = readOnly;
}
/*
* Tests to see if the connection is in Read Only Mode. Note that
* we cannot really put the database in read only mode, but we pretend
* we can by returning the value of the readOnly flag
*
* @return true if the connection is read only
* @exception SQLException if a database access error occurs
*/
public boolean isReadOnly() throws SQLException
{
return readOnly;
}
/*
* If a connection is in auto-commit mode, than all its SQL
* statements will be executed and committed as individual
* transactions. Otherwise, its SQL statements are grouped
* into transactions that are terminated by either commit()
* or rollback(). By default, new connections are in auto-
* commit mode. The commit occurs when the statement completes
* or the next execute occurs, whichever comes first. In the
* case of statements returning a ResultSet, the statement
* completes when the last row of the ResultSet has been retrieved
* or the ResultSet has been closed. In advanced cases, a single
* statement may return multiple results as well as output parameter
* values. Here the commit occurs when all results and output param
* values have been retrieved.
*
* @param autoCommit - true enables auto-commit; false disables it
* @exception SQLException if a database access error occurs
*/
public void setAutoCommit(boolean autoCommit) throws SQLException
{
if (this.autoCommit == autoCommit)
return;
if (autoCommit)
ExecSQL("end");
else
{
if (haveMinimumServerVersion("7.1"))
{
ExecSQL("begin;" + getIsolationLevelSQL());
}
else
{
ExecSQL("begin");
ExecSQL(getIsolationLevelSQL());
}
}
this.autoCommit = autoCommit;
}
/*
* gets the current auto-commit state
*
* @return Current state of the auto-commit mode
* @exception SQLException (why?)
* @see setAutoCommit
*/
public boolean getAutoCommit() throws SQLException
{
return this.autoCommit;
}
/*
* The method commit() makes all changes made since the previous
* commit/rollback permanent and releases any database locks currently
* held by the Connection. This method should only be used when
* auto-commit has been disabled. (If autoCommit == true, then we
* just return anyhow)
*
* @exception SQLException if a database access error occurs
* @see setAutoCommit
*/
public void commit() throws SQLException
{
if (autoCommit)
return;
if (haveMinimumServerVersion("7.1"))
{
ExecSQL("commit;begin;" + getIsolationLevelSQL());
}
else
{
ExecSQL("commit");
ExecSQL("begin");
ExecSQL(getIsolationLevelSQL());
}
}
/*
* The method rollback() drops all changes made since the previous
* commit/rollback and releases any database locks currently held by
* the Connection.
*
* @exception SQLException if a database access error occurs
* @see commit
*/
public void rollback() throws SQLException
{
if (autoCommit)
return;
if (haveMinimumServerVersion("7.1"))
{
ExecSQL("rollback; begin;" + getIsolationLevelSQL());
}
else
{
ExecSQL("rollback");
ExecSQL("begin");
ExecSQL(getIsolationLevelSQL());
}
}
/*
* Get this Connection's current transaction isolation mode.
*
* @return the current TRANSACTION_* mode value
* @exception SQLException if a database access error occurs
*/
public int getTransactionIsolation() throws SQLException
{
clearWarnings();
ExecSQL("show xactisolevel");
SQLWarning warning = getWarnings();
if (warning != null)
{
String message = warning.getMessage();
clearWarnings();
if (message.indexOf("READ COMMITTED") != -1)
return java.sql.Connection.TRANSACTION_READ_COMMITTED;
else if (message.indexOf("READ UNCOMMITTED") != -1)
return java.sql.Connection.TRANSACTION_READ_UNCOMMITTED;
else if (message.indexOf("REPEATABLE READ") != -1)
return java.sql.Connection.TRANSACTION_REPEATABLE_READ;
else if (message.indexOf("SERIALIZABLE") != -1)
return java.sql.Connection.TRANSACTION_SERIALIZABLE;
}
return java.sql.Connection.TRANSACTION_READ_COMMITTED;
}
/*
* You can call this method to try to change the transaction
* isolation level using one of the TRANSACTION_* values.
*
* <B>Note:</B> setTransactionIsolation cannot be called while
* in the middle of a transaction
*
* @param level one of the TRANSACTION_* isolation values with
* the exception of TRANSACTION_NONE; some databases may
* not support other values
* @exception SQLException if a database access error occurs
* @see java.sql.DatabaseMetaData#supportsTransactionIsolationLevel
*/
public void setTransactionIsolation(int level) throws SQLException
{
//In 7.1 and later versions of the server it is possible using
//the "set session" command to set this once for all future txns
//however in 7.0 and prior versions it is necessary to set it in
//each transaction, thus adding complexity below.
//When we decide to drop support for servers older than 7.1
//this can be simplified
isolationLevel = level;
String isolationLevelSQL;
if (!haveMinimumServerVersion("7.1"))
{
isolationLevelSQL = getIsolationLevelSQL();
}
else
{
isolationLevelSQL = "SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL ";
switch (isolationLevel)
{
case java.sql.Connection.TRANSACTION_READ_COMMITTED:
isolationLevelSQL += "READ COMMITTED";
break;
case java.sql.Connection.TRANSACTION_SERIALIZABLE:
isolationLevelSQL += "SERIALIZABLE";
break;
default:
throw new PSQLException("postgresql.con.isolevel",
new Integer(isolationLevel));
}
}
ExecSQL(isolationLevelSQL);
}
/*
* Helper method used by setTransactionIsolation(), commit(), rollback()
* and setAutoCommit(). This returns the SQL string needed to
* set the isolation level for a transaction. In 7.1 and later it
* is possible to set a default isolation level that applies to all
* future transactions, this method is only necesary for 7.0 and older
* servers, and should be removed when support for these older
* servers are dropped
*/
protected String getIsolationLevelSQL() throws SQLException
{
//7.1 and higher servers have a default specified so
//no additional SQL is required to set the isolation level
if (haveMinimumServerVersion("7.1"))
{
return "";
}
StringBuffer sb = new StringBuffer("SET TRANSACTION ISOLATION LEVEL");
switch (isolationLevel)
{
case java.sql.Connection.TRANSACTION_READ_COMMITTED:
sb.append(" READ COMMITTED");
break;
case java.sql.Connection.TRANSACTION_SERIALIZABLE:
sb.append(" SERIALIZABLE");
break;
default:
throw new PSQLException("postgresql.con.isolevel", new Integer(isolationLevel));
}
return sb.toString();
}
/*
* A sub-space of this Connection's database may be selected by
* setting a catalog name. If the driver does not support catalogs,
* it will silently ignore this request
*
* @exception SQLException if a database access error occurs
*/
public void setCatalog(String catalog) throws SQLException
{
//no-op
}
/*
* Return the connections current catalog name, or null if no
* catalog name is set, or we dont support catalogs.
*
* @return the current catalog name or null
* @exception SQLException if a database access error occurs
*/
public String getCatalog() throws SQLException
{
return PG_DATABASE;
}
/*
* Overides finalize(). If called, it closes the connection.
*
* This was done at the request of Rachel Greenham
* <rachel@enlarion.demon.co.uk> who hit a problem where multiple
* clients didn't close the connection, and once a fortnight enough
* clients were open to kill the org.postgres server.
*/
public void finalize() throws Throwable
{
close();
}
private static String extractVersionNumber(String fullVersionString)
{
StringTokenizer versionParts = new StringTokenizer(fullVersionString);
versionParts.nextToken(); /* "PostgreSQL" */
return versionParts.nextToken(); /* "X.Y.Z" */
}
/*
* Get server version number
*/
public String getDBVersionNumber()
{
return dbVersionNumber;
}
public boolean haveMinimumServerVersion(String ver) throws SQLException
{
return (getDBVersionNumber().compareTo(ver) >= 0);
}
/*
* This method returns true if the compatible level set in the connection
* (which can be passed into the connection or specified in the URL)
* is at least the value passed to this method. This is used to toggle
* between different functionality as it changes across different releases
* of the jdbc driver code. The values here are versions of the jdbc client
* and not server versions. For example in 7.1 get/setBytes worked on
* LargeObject values, in 7.2 these methods were changed to work on bytea
* values. This change in functionality could be disabled by setting the
* "compatible" level to be 7.1, in which case the driver will revert to
* the 7.1 functionality.
*/
public boolean haveMinimumCompatibleVersion(String ver) throws SQLException
{
return (compatible.compareTo(ver) >= 0);
}
/*
* This returns the java.sql.Types type for a PG type oid
*
* @param oid PostgreSQL type oid
* @return the java.sql.Types type
* @exception SQLException if a database access error occurs
*/
public int getSQLType(int oid) throws SQLException
{
Integer sqlType = (Integer)sqlTypeCache.get(new Integer(oid));
// it's not in the cache, so perform a query, and add the result to the cache
if (sqlType == null)
{
ResultSet result = (org.postgresql.ResultSet)ExecSQL("select typname from pg_type where oid = " + oid);
if (result.getColumnCount() != 1 || result.getTupleCount() != 1)
throw new PSQLException("postgresql.unexpected");
result.next();
String pgType = result.getString(1);
Integer iOid = new Integer(oid);
sqlType = new Integer(getSQLType(result.getString(1)));
sqlTypeCache.put(iOid, sqlType);
pgTypeCache.put(iOid, pgType);
result.close();
}
return sqlType.intValue();
}
/*
* This returns the java.sql.Types type for a PG type
*
* @param pgTypeName PostgreSQL type name
* @return the java.sql.Types type
*/
public abstract int getSQLType(String pgTypeName);
/*
* This returns the oid for a given PG data type
* @param typeName PostgreSQL type name
* @return PostgreSQL oid value for a field of this type
*/
public int getOID(String typeName) throws SQLException
{
int oid = -1;
if (typeName != null)
{
Integer oidValue = (Integer) typeOidCache.get(typeName);
if (oidValue != null)
{
oid = oidValue.intValue();
}
else
{
// it's not in the cache, so perform a query, and add the result to the cache
ResultSet result = (org.postgresql.ResultSet)ExecSQL("select oid from pg_type where typname='"
+ typeName + "'");
if (result.getColumnCount() != 1 || result.getTupleCount() != 1)
throw new PSQLException("postgresql.unexpected");
result.next();
oid = Integer.parseInt(result.getString(1));
typeOidCache.put(typeName, new Integer(oid));
result.close();
}
}
return oid;
}
/*
* We also need to get the PG type name as returned by the back end.
*
* @return the String representation of the type of this field
* @exception SQLException if a database access error occurs
*/
public String getPGType(int oid) throws SQLException
{
String pgType = (String) pgTypeCache.get(new Integer(oid));
if (pgType == null)
{
getSQLType(oid);
pgType = (String) pgTypeCache.get(new Integer(oid));
}
return pgType;
}
}
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