package org.postgresql.util;

import java.io.*;
import java.lang.*;
import java.sql.*;
import java.util.*;

/**
 * org.postgresql.PG_Object is a class used to describe unknown types
 * An unknown type is any type that is unknown by JDBC Standards
 *
 * <p>As of PostgreSQL 6.3, this allows user code to add their own
 * handlers via a call to org.postgresql.Connection. These handlers
 * must extend this class.
 */
public class PGobject implements Serializable, Cloneable
{
	protected String	type;
	protected String	value;

	/**
	 * This is called by org.postgresql.Connection.getObject() to create the
	 * object.
	 */
	public PGobject()
	{}

	/**
	 * This method sets the type of this object.
	 *
	 * <p>It should not be extended by subclasses, hence its final
	 *
	 * @param type a string describing the type of the object
	 */
	public final void setType(String type)
	{
		this.type = type;
	}

	/**
	 * This method sets the value of this object. It must be overidden.
	 *
	 * @param value a string representation of the value of the object
	 * @exception SQLException thrown if value is invalid for this type
	 */
	public void setValue(String value) throws SQLException
	{
		this.value = value;
	}

	/**
	 * As this cannot change during the life of the object, it's final.
	 * @return the type name of this object
	 */
	public final String getType()
	{
		return type;
	}

	/**
	 * This must be overidden, to return the value of the object, in the
	 * form required by org.postgresql.
	 * @return the value of this object
	 */
	public String getValue()
	{
		return value;
	}

	/**
	 * This must be overidden to allow comparisons of objects
	 * @param obj Object to compare with
	 * @return true if the two boxes are identical
	 */
	public boolean equals(Object obj)
	{
		if (obj instanceof PGobject)
			return ((PGobject)obj).getValue().equals(getValue());
		return false;
	}

	/**
	 * This must be overidden to allow the object to be cloned
	 */
	public Object clone()
	{
		PGobject obj = new PGobject();
		obj.type = type;
		obj.value = value;
		return obj;
	}

	/**
	 * This is defined here, so user code need not overide it.
	 * @return the value of this object, in the syntax expected by org.postgresql
	 */
	public String toString()
	{
		return getValue();
	}
}
