PojoMessageHandlerWholeBase.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tomcat.websocket.pojo;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import javax.naming.NamingException;
import jakarta.websocket.DecodeException;
import jakarta.websocket.Decoder;
import jakarta.websocket.MessageHandler;
import jakarta.websocket.Session;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.InstanceManager;
import org.apache.tomcat.util.res.StringManager;
import org.apache.tomcat.websocket.WsSession;
/**
* Common implementation code for the POJO whole message handlers. All the real work is done in this class and in the
* superclass.
*
* @param <T> The type of message to handle
*/
public abstract class PojoMessageHandlerWholeBase<T> extends PojoMessageHandlerBase<T>
implements MessageHandler.Whole<T> {
private final Log log = LogFactory.getLog(PojoMessageHandlerWholeBase.class); // must not be static
private static final StringManager sm = StringManager.getManager(PojoMessageHandlerWholeBase.class);
protected final List<Decoder> decoders = new ArrayList<>();
public PojoMessageHandlerWholeBase(Object pojo, Method method, Session session, Object[] params, int indexPayload,
boolean convert, int indexSession, long maxMessageSize) {
super(pojo, method, session, params, indexPayload, convert, indexSession, maxMessageSize);
}
protected Decoder createDecoderInstance(Class<? extends Decoder> clazz)
throws ReflectiveOperationException, NamingException {
InstanceManager instanceManager = ((WsSession) session).getInstanceManager();
if (instanceManager == null) {
return clazz.getConstructor().newInstance();
} else {
return (Decoder) instanceManager.newInstance(clazz);
}
}
@Override
public final void onMessage(T message) {
if (params.length == 1 && params[0] instanceof DecodeException) {
((WsSession) session).getLocal().onError(session, (DecodeException) params[0]);
return;
}
// Can this message be decoded?
Object payload;
try {
payload = decode(message);
} catch (DecodeException de) {
((WsSession) session).getLocal().onError(session, de);
return;
}
if (payload == null) {
// Not decoded. Convert if required.
if (convert) {
payload = convert(message);
} else {
payload = message;
}
}
Object[] parameters = params.clone();
if (indexSession != -1) {
parameters[indexSession] = session;
}
parameters[indexPayload] = payload;
Object result = null;
try {
result = method.invoke(pojo, parameters);
} catch (InvocationTargetException e) {
handlePojoMethodInvocationTargetException(e);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
processResult(result);
}
protected void onClose() {
InstanceManager instanceManager = ((WsSession) session).getInstanceManager();
for (Decoder decoder : decoders) {
decoder.destroy();
if (instanceManager != null) {
try {
instanceManager.destroyInstance(decoder);
} catch (IllegalAccessException | InvocationTargetException e) {
log.warn(sm.getString("pojoMessageHandlerWholeBase.decodeDestoryFailed", decoder.getClass()), e);
}
}
}
}
protected Object convert(T message) {
return message;
}
protected abstract Object decode(T message) throws DecodeException;
}