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package org.hsqldb.types;

import java.io.Serializable;

import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.InOutUtil;

Represents of an instance of an OTHER field value. 

Prior to 1.7.0 there were problems storing Objects of normal column types
in columns of the type OTHER. In 1.7.0 changes were made to allow this,
but as all the conversion took place inside the engine, it introduced a
requirement for all classes for objects stored in OTHER columns to be
available on the runtime class path of the engine. 

In 1.7.2, the introduction of real prepared statement support allows us
revert to the pre 1.7.0 behaviour without the artificial limitations. 

The classes for stored objects need not be available to open and operate
the database in general. The classes need to be available only if a
conversion from one of these objects to another type is performed inside
the engine while operating the database.
The current limitation is that in SQL statements, values of type String
(CHARACTER and related SQL types) cannot be stored in columns of type
OTHER. This limitation does not exist for String values assigned to
PreparedStatement variables.
Author:
Fred Toussi (fredt@users dot sourceforge.net)
Version:
2.3.4
Since:
1.7.2/**
 * Represents of an instance of an OTHER field value. <p>
 *
 * Prior to 1.7.0 there were problems storing Objects of normal column types
 * in columns of the type OTHER. In 1.7.0 changes were made to allow this,
 * but as all the conversion took place inside the engine, it introduced a
 * requirement for all classes for objects stored in OTHER columns to be
 * available on the runtime class path of the engine. <p>
 *
 * In 1.7.2, the introduction of real prepared statement support allows us
 * revert to the pre 1.7.0 behaviour without the artificial limitations. <p>
 *
 * The classes for stored objects need not be available to open and operate
 * the database in general. The classes need to be available only if a
 * conversion from one of these objects to another type is performed inside
 * the engine while operating the database.
 *
 * The current limitation is that in SQL statements, values of type String
 * (CHARACTER and related SQL types) cannot be stored in columns of type
 * OTHER. This limitation does not exist for String values assigned to
 * PreparedStatement variables.
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.3.4
 * @since 1.7.2
 */
public class JavaObjectData {

    private byte[] data;

    JavaObjectData() {}

    
Constructor used inside the engine when an already serialized
Object is read from a file (.log, .script, .data or text table source).
/**
     * Constructor used inside the engine when an already serialized
     * Object is read from a file (.log, .script, .data or text table source).
     */
    public JavaObjectData(byte[] data) {
        this.data = data;
    }

    
Constructor used inside the engine to convert an Object into an
object of type OTHER.
Used also with JDBC setParameter().
If parameter serialize is true, the Object is serialized for storage.
/**
     * Constructor used inside the engine to convert an Object into an
     * object of type OTHER.
     * Used also with JDBC setParameter().
     * If parameter serialize is true, the Object is serialized for storage.
     */
    public JavaObjectData(Serializable o) {

        try {
            data = InOutUtil.serialize(o);
        } catch (Exception e) {
            throw Error.error(ErrorCode.X_22521, e.toString());
        }
    }

    public byte[] getBytes() {
        return data;
    }

    public int getBytesLength() {
        return data.length;
    }

    
This method is called from classes implementing the JDBC
interfaces. Inside the engine it is used for conversion from a value of
type OTHER to another type. It will throw if the OTHER is an instance
of a class that is not available.
/**
     * This method is called from classes implementing the JDBC
     * interfaces. Inside the engine it is used for conversion from a value of
     * type OTHER to another type. It will throw if the OTHER is an instance
     * of a class that is not available.
     */
    public Object getObject() {

        try {
            return InOutUtil.deserialize(data);
        } catch (Exception e) {
            throw Error.error(ErrorCode.X_22521, e.toString());
        }
    }

    
Returns String representation of this object.
Returns:
a String representation of this object./**
     * Returns String representation of this object.
     *
     * @return a String representation of this object.
     */
    public String toString() {
        return super.toString();
    }

    public boolean equals(Object other) {
        return other instanceof JavaObjectData;
    }

    public int hashCode() {
        return 1;
    }
}