/*
* Copyright 2009 JBoss, a divison Red Hat, Inc
*
* Licensed 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.jboss.errai.bus.server;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import org.jboss.errai.bus.client.CommandMessage;
import org.jboss.errai.bus.client.Message;
import org.jboss.errai.bus.client.MessageBus;
import org.jboss.errai.bus.server.service.ErraiService;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Reader;
import java.nio.CharBuffer;
import java.util.Iterator;
import java.util.List;
import static org.jboss.errai.bus.server.io.MessageUtil.createCommandMessage;
/**
* The default ErraiServletImpl which provides the HTTP-protocol gateway between the server bus and the client buses.
*/
@Singleton
public class ErraiServletImpl extends HttpServlet {
private ErraiService service;
@Inject
public ErraiServletImpl(ErraiService service) {
this.service = service;
}
@Override
protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse)
throws ServletException, IOException {
pollForMessages(httpServletRequest, httpServletResponse, true);
}
@Override
protected void doPost(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse)
throws ServletException, IOException {
Reader reader = httpServletRequest.getReader();
StringBuilder sb = new StringBuilder(httpServletRequest.getContentLength());
HttpSession session = httpServletRequest.getSession();
CharBuffer buffer = CharBuffer.allocate(10);
int read;
while ((read = reader.read(buffer)) > 0) {
buffer.rewind();
for (; read > 0; read--) {
sb.append(buffer.get());
}
buffer.rewind();
}
if (session.getAttribute(MessageBus.WS_SESSION_ID) == null) {
session.setAttribute(MessageBus.WS_SESSION_ID, httpServletRequest.getSession().getId());
}
for (CommandMessage msg : createCommandMessage(httpServletRequest.getSession(), sb.toString())) {
service.store(msg);
}
pollForMessages(httpServletRequest, httpServletResponse, false);
}
private void pollForMessages(HttpServletRequest httpServletRequest,
HttpServletResponse httpServletResponse, boolean wait) throws IOException {
try {
List<Message> messages = service.getBus().nextMessage(
httpServletRequest.getSession().getAttribute(MessageBus.WS_SESSION_ID), wait).getMessages();
httpServletResponse.setHeader("Cache-Control", "no-cache");
httpServletResponse.addHeader("Payload-Size", String.valueOf(messages.size()));
httpServletResponse.setContentType("application/io");
OutputStream stream = httpServletResponse.getOutputStream();
Iterator<Message> iter = messages.iterator();
Message m;
stream.write('[');
while (iter.hasNext()) {
writeToOutputStream(stream, iter.next());
if (iter.hasNext()) {
stream.write(',');
}
}
stream.write(']');
stream.close();
}
catch (final Throwable t) {
httpServletResponse.setHeader("Cache-Control", "no-cache");
httpServletResponse.addHeader("Payload-Size", "1");
httpServletResponse.setContentType("application/io");
OutputStream stream = httpServletResponse.getOutputStream();
stream.write('[');
writeToOutputStream(stream, new Message() {
public String getSubject() {
return "ClientBusErrors";
}
public Object getMessage() {
StringBuilder b = new StringBuilder("{ErrorMessage:\"").append(t.getMessage()).append("\",AdditionalDetails:\"");
for (StackTraceElement e : t.getStackTrace()) {
b.append(e.toString()).append("<br/>");
}
return b.append("\"}").toString();
}
});
stream.write(']');
}
}
public static void writeToOutputStream(OutputStream stream, Message m) throws IOException {
stream.write('{');
stream.write('"');
for (byte b : (m.getSubject()).getBytes()) {
stream.write(b);
}
stream.write('"');
stream.write(':');
if (m.getMessage() == null) {
stream.write('n');
stream.write('u');
stream.write('l');
stream.write('l');
} else {
for (byte b : ((String) m.getMessage()).getBytes()) {
stream.write(b);
}
}
stream.write('}');
}
}