001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.activemq.transport.xstream; 018 019import java.io.IOException; 020import java.io.Reader; 021import com.thoughtworks.xstream.XStream; 022import org.apache.activemq.command.ConsumerInfo; 023 024import com.thoughtworks.xstream.converters.Converter; 025import com.thoughtworks.xstream.converters.ConverterLookup; 026import com.thoughtworks.xstream.converters.MarshallingContext; 027import com.thoughtworks.xstream.converters.UnmarshallingContext; 028import com.thoughtworks.xstream.io.HierarchicalStreamReader; 029import com.thoughtworks.xstream.io.HierarchicalStreamWriter; 030import org.apache.activemq.command.MarshallAware; 031import org.apache.activemq.command.MessageDispatch; 032import org.apache.activemq.command.TransientInitializer; 033import org.apache.activemq.transport.stomp.XStreamSupport; 034import org.apache.activemq.transport.util.TextWireFormat; 035import org.apache.activemq.util.ByteSequence; 036import org.apache.activemq.wireformat.WireFormat; 037 038/** 039 * A {@link WireFormat} implementation which uses the <a 040 * href="http://xstream.codehaus.org/>XStream</a> library to marshall commands 041 * onto the wire 042 * 043 * 044 */ 045public class XStreamWireFormat extends TextWireFormat { 046 private XStream xStream; 047 private int version; 048 049 @Override 050 public int getVersion() { 051 return version; 052 } 053 054 @Override 055 public void setVersion(int version) { 056 this.version = version; 057 } 058 059 public WireFormat copy() { 060 return new XStreamWireFormat(); 061 } 062 063 @Override 064 public Object unmarshalText(String text) { 065 return getXStream().fromXML(text); 066 } 067 068 @Override 069 public Object unmarshalText(Reader reader) { 070 Object val = getXStream().fromXML(reader); 071 if (val instanceof TransientInitializer) { 072 ((TransientInitializer)val).initTransients(); 073 } 074 return val; 075 } 076 077 @Override 078 public String marshalText(Object command) throws IOException { 079 if (command instanceof MarshallAware) { 080 ((MarshallAware)command).beforeMarshall(this); 081 } else if(command instanceof MessageDispatch) { 082 MessageDispatch dispatch = (MessageDispatch) command; 083 if (dispatch != null && dispatch.getMessage() != null) { 084 dispatch.getMessage().beforeMarshall(this); 085 } 086 } 087 088 return getXStream().toXML(command); 089 } 090 091 /** 092 * Can this wireformat process packets of this version 093 * 094 * @param version the version number to test 095 * @return true if can accept the version 096 */ 097 public boolean canProcessWireFormatVersion(int version) { 098 return true; 099 } 100 101 /** 102 * @return the current version of this wire format 103 */ 104 public int getCurrentWireFormatVersion() { 105 return 1; 106 } 107 108 // Properties 109 // ------------------------------------------------------------------------- 110 public XStream getXStream() { 111 if (xStream == null) { 112 xStream = createXStream(); 113 // make it work in OSGi env 114 xStream.setClassLoader(getClass().getClassLoader()); 115 } 116 return xStream; 117 } 118 119 public void setXStream(XStream xStream) { 120 this.xStream = xStream; 121 } 122 123 // Implementation methods 124 // ------------------------------------------------------------------------- 125 protected XStream createXStream() { 126 final XStream xstream = XStreamSupport.createXStream(); 127 xstream.ignoreUnknownElements(); 128 xstream.registerConverter(new Converter() { 129 final Converter delegate = xstream.getConverterLookup().lookupConverterForType(ByteSequence.class); 130 @Override 131 public void marshal(Object o, HierarchicalStreamWriter hierarchicalStreamWriter, MarshallingContext marshallingContext) { 132 ByteSequence byteSequence = (ByteSequence)o; 133 byteSequence.compact(); 134 delegate.marshal(byteSequence, hierarchicalStreamWriter, marshallingContext); 135 } 136 137 @Override 138 public Object unmarshal(HierarchicalStreamReader hierarchicalStreamReader, UnmarshallingContext unmarshallingContext) { 139 return delegate.unmarshal(hierarchicalStreamReader, unmarshallingContext); 140 } 141 142 @Override 143 public boolean canConvert(Class aClass) { 144 return aClass == ByteSequence.class; 145 } 146 }); 147 return xstream; 148 } 149 150}