package postgresql.util;

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

/**
 * 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 postgresql.Connection. These handlers
 * must extend this class.
 */
public class PGobject implements Serializable,Cloneable
{
  protected String	type;
  protected String	value;
  
  /**
   * This is called by 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 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 postgresql
   */
  public String toString()
  {
    return getValue();
  }
}
