mapmessageimpl.java

来自「OpenJMS是一个开源的Java Message Service API 1.」· Java 代码 · 共 616 行 · 第 1/2 页

/**
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
 *    statements and notices.  Redistributions must also contain a
 *    copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the
 *    above copyright notice, this list of conditions and the
 *    following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of Exoffice Technologies.  For written permission,
 *    please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "Exolab"
 *    nor may "Exolab" appear in their names without prior written
 *    permission of Exoffice Technologies. Exolab is a registered
 *    trademark of Exoffice Technologies.
 *
 * 5. Due credit should be given to the Exolab Project
 *    (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 2000-2003 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: MapMessageImpl.java,v 1.1 2004/11/26 01:50:43 tanderson Exp $
 *
 * Date         Author  Changes
 * 02/26/2000   jimm    Created
 */

package org.exolab.jms.message;

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;

import javax.jms.JMSException;
import javax.jms.MapMessage;
import javax.jms.MessageFormatException;
import javax.jms.MessageNotWriteableException;


/**
 * This class implements the {@link javax.jms.MapMessage} interface.
 * <p>
 * A MapMessage is used to send a set of name-value pairs where names are
 * Strings and values are Java primitive types. The entries can be accessed
 * sequentially or randomly by name. The order of the entries is undefined.
 * It inherits from <code>Message</code> and adds a map message body.
 * <p>
 * The primitive types can be read or written explicitly using methods
 * for each type. They may also be read or written generically as objects.
 * For instance, a call to <code>MapMessage.setInt("foo", 6)</code> is
 * equivalent to <code>MapMessage.setObject("foo", new Integer(6))</code>.
 * Both forms are provided because the explicit form is convenient for
 * static programming and the object form is needed when types are not known
 * at compile time.
 * <p>
 * When a client receives a MapMessage, it is in read-only mode. If a
 * client attempts to write to the message at this point, a
 * MessageNotWriteableException is thrown. If {@link #clearBody} is
 * called, the message can now be both read from and written to.
 * <p>
 * Map messages support the following conversion table. The marked cases
 * must be supported. The unmarked cases must throw a JMSException. The
 * String to primitive conversions may throw a runtime exception if the
 * primitives <code>valueOf()</code> method does not accept it as a valid
 * String representation of the primitive.
 * <p>
 * A value written as the row type can be read as the column type.
 *
 * <pre>
 * |        | boolean byte short char int long float double String byte[]
 * |----------------------------------------------------------------------
 * |boolean |    X                                            X
 * |byte    |          X     X         X   X                  X
 * |short   |                X         X   X                  X
 * |char    |                     X                           X
 * |int     |                          X   X                  X
 * |long    |                              X                  X
 * |float   |                                    X     X      X
 * |double  |                                          X      X
 * |String  |    X     X     X         X   X     X     X      X
 * |byte[]  |                                                        X
 * |----------------------------------------------------------------------
 * </pre>
 *
 * <p>
 * Attempting to read a null value as a Java primitive type must be treated
 * as calling the primitive's corresponding <code>valueOf(String)</code>
 * conversion method with a null value. Since char does not support a
 * String conversion, attempting to read a null value as a char must
 * throw NullPointerException.
 *
 * @version     $Revision: 1.1 $ $Date: 2004/11/26 01:50:43 $
 * @author      <a href="mailto:[e-mail]">Jim Mourikis</a>
 * @see         javax.jms.MapMessage
 */
public class MapMessageImpl extends MessageImpl implements MapMessage {

    /**
     * Object version no. for serialization
     */
    static final long serialVersionUID = 2;

    /**
     * The initial size of the map
     */
    private static final int INITIAL_SIZE = 20;

    /**
     * The container for all message data
     */
    private HashMap _map = new HashMap(INITIAL_SIZE);

    /**
     * Construct a new MapMessage
     *
     * @throws JMSException if the message type can't be set
     */
    public MapMessageImpl() throws JMSException {
        setJMSType("MapMessage");
    }

    /**
     * Clone an instance of this object
     *
     * @return a copy of this object
     * @throws CloneNotSupportedException if object or attributes aren't
     * cloneable
     */
    public final Object clone() throws CloneNotSupportedException {
        MapMessageImpl result = (MapMessageImpl) super.clone();
        result._map = (HashMap) _map.clone();
        return result;
    }

    /**
     * Serialize out this message's data
     *
     * @param out the stream to serialize out to
     * @throws IOException if any I/O exceptions occurr
     */
    public final void writeExternal(ObjectOutput out) throws IOException {
        super.writeExternal(out);
        out.writeLong(serialVersionUID);
        out.writeObject(_map);
    }

    /**
     * Serialize in this message's data
     *
     * @param in the stream to serialize in from
     * @throws ClassNotFoundException if the class for an object being
     * restored cannot be found.
     * @throws IOException if any I/O exceptions occur
     */
    public final void readExternal(ObjectInput in)
        throws ClassNotFoundException, IOException {
        super.readExternal(in);
        long version = in.readLong();
        if (version == serialVersionUID) {
            _map = (HashMap) in.readObject();
        } else {
            throw new IOException("Incorrect version enountered: " + version +
                ". This version = " + serialVersionUID);
        }
    }

    /**
     * Return the boolean value with the given name
     *
     * @param name the name of the boolean
     * @return the boolean value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final boolean getBoolean(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getBoolean(_map.get(name));
    }

    /**
     * Return the byte value with the given name
     *
     * @param name the name of the byte
     * @return the byte value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final byte getByte(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getByte(_map.get(name));
    }

    /**
     * Return the short value with the given name
     *
     * @param name the name of the short
     * @return the short value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final short getShort(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getShort(_map.get(name));
    }

    /**
     * Return the Unicode character value with the given name
     *
     * @param name the name of the Unicode character
     * @return the Unicode character value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final char getChar(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getChar(_map.get(name));
    }

    /**
     * Return the integer value with the given name
     *
     * @param name the name of the integer
     * @return the integer value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final int getInt(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getInt(_map.get(name));
    }

    /**
     * Return the long value with the given name
     *
     * @param name the name of the long
     * @return the long value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final long getLong(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getLong(_map.get(name));
    }

    /**
     * Return the float value with the given name
     *
     * @param name the name of the float
     * @return the float value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final float getFloat(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getFloat(_map.get(name));
    }

    /**
     * Return the double value with the given name
     *
     * @param name the name of the double
     * @return the double value with the given name
     * @throws JMSException if JMS fails to read the message due to some
     * internal JMS error
     * @throws MessageFormatException if this type conversion is invalid
     */
    public final double getDouble(String name)
        throws JMSException, MessageFormatException {
        return FormatConverter.getDouble(_map.get(name));
    }

    /**
     * Return the String value with the given name
     *
     * @param name the name of the String
     * @return the String value with the given name. If there is no item
     * by this name, a null value is returned.