I'm trying to write an Http Server using Apache Mina.
According to Mina's architecture, there should be 2 filters for this task, one for Http Request Passing and another for processing the request and generating the response. So using the Mina example codes, I came up with the following code, that has an acceptor, logging filter, Http filter, and a filter for processing request.
Initiation of the server runs correctly, but the request does not come to DummyHttpSever filter. I tried to debug, but could not find the issue. What is going wrong here?
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.mina.filter.logging.LoggingFilter;
import org.apache.mina.api.AbstractIoFilter;
import org.apache.mina.api.IoSession;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filterchain.ReadFilterChainController;
import org.apache.mina.http.DateUtil;
import org.apache.mina.http.HttpDecoderState;
import org.apache.mina.http.HttpServerDecoder;
import org.apache.mina.http.HttpServerEncoder;
import org.apache.mina.http.api.DefaultHttpResponse;
import org.apache.mina.http.api.HttpContentChunk;
import org.apache.mina.http.api.HttpEndOfContent;
import org.apache.mina.http.api.HttpMethod;
import org.apache.mina.http.api.HttpPdu;
import org.apache.mina.http.api.HttpRequest;
import org.apache.mina.http.api.HttpStatus;
import org.apache.mina.http.api.HttpVersion;
import org.apache.mina.transport.nio.NioTcpServer;
public class HttpTest {
public static void main(String[] args) throws Exception {
NioTcpServer httpServer = new NioTcpServer();
httpServer.setReuseAddress(true);
httpServer.setFilters(new ProtocolCodecFilter<HttpPdu, ByteBuffer, Void, HttpDecoderState>(new HttpServerEncoder(),
new HttpServerDecoder()), new LoggingFilter("DECODED"), new DummyHttpSever());
httpServer.getSessionConfig().setTcpNoDelay(true);
httpServer.bind(new InetSocketAddress(8080));
// run for 20 seconds
Thread.sleep(2000000000);
httpServer.unbind();
}
private static class DummyHttpSever extends AbstractIoFilter {
private HttpRequest incomingRequest;
private List<ByteBuffer> body;
@Override
public void messageReceived(IoSession session, Object message, ReadFilterChainController controller) {
if (message instanceof HttpRequest) {
System.out.println("This shit is working");
incomingRequest = (HttpRequest) message;
body = new ArrayList<ByteBuffer>();
// check if this request is going to be followed by and HTTP body or not
if (incomingRequest.getMethod() != HttpMethod.POST && incomingRequest.getMethod() != HttpMethod.PUT) {
sendResponse(session, incomingRequest);
} else {
}
} else if (message instanceof ByteBuffer) {
body.add((ByteBuffer) message);
} else if (message instanceof HttpEndOfContent) {
// we received all the post content, send the crap back
sendResponse(session, incomingRequest);
}
}
public void sendResponse(IoSession session, HttpRequest request) {
Map<String, String> headers = new HashMap<String, String>();
headers.put("Server", "Apache MINA Dummy test server/0.0.");
headers.put("Date", DateUtil.getCurrentAsString());
headers.put("Connection", "Close");
String strContent = "Hello ! we reply to request !";
ByteBuffer content = ByteBuffer.wrap(strContent.getBytes());
// compute content len
headers.put("Content-Length", String.valueOf(content.remaining()));
session.write(new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpStatus.SUCCESS_OK, headers));
session.write(new HttpContentChunk(content));
session.write(new HttpEndOfContent());
session.close(false);
}
}
}
Also, following are dependencies I am using.
<dependency>
<groupId>org.apache.mina</groupId>
<artifactId>mina-core</artifactId>
<version>2.0.7</version>
</dependency>
<dependency>
<groupId>org.apache.mina</groupId>
<artifactId>mina-http</artifactId>
<version>2.0.7</version>
</dependency>
<dependency>
<groupId>org.apache.mina</groupId>
<artifactId>mina-coap</artifactId>
<version>2.0.7</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>LATEST</version>
</dependency>
This is a simple Http web server, which you can modify according to your need. This example is a modification to the example lightweight component of Apache Mina examples.
Main.java
import java.net.InetSocketAddress;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.asyncweb.common.codec.HttpCodecFactory;
import org.apache.asyncweb.examples.lightweight.HttpProtocolHandler;
import org.apache.mina.transport.socket.SocketAcceptor;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;
public class Main {
public static void main(String[] args) throws Exception {
SocketAcceptor acceptor = new NioSocketAcceptor();
acceptor.getFilterChain().addLast("codec",
new ProtocolCodecFilter(new HttpCodecFactory()));
acceptor.setReuseAddress(true);
acceptor.getSessionConfig().setReuseAddress(true);
acceptor.getSessionConfig().setReceiveBufferSize(1024);
acceptor.getSessionConfig().setSendBufferSize(1024);
acceptor.getSessionConfig().setTcpNoDelay(true);
acceptor.getSessionConfig().setSoLinger(-1);
acceptor.setBacklog(10240);
acceptor.setHandler(new HttpProtocolHandler());
acceptor.bind(new InetSocketAddress(9012));
}
}
HttpProtocalHandler.java
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.future.IoFutureListener;
import org.apache.mina.core.service.IoHandler;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.core.future.WriteFuture;
import org.apache.asyncweb.common.HttpRequest;
import org.apache.asyncweb.common.HttpResponseStatus;
import org.apache.asyncweb.common.MutableHttpResponse;
import org.apache.asyncweb.common.DefaultHttpResponse;
import org.apache.asyncweb.common.HttpHeaderConstants;
public class HttpProtocolHandler implements IoHandler {
private static final int CONTENT_PADDING = 0; // 101
private final Map<Integer, IoBuffer> buffers = new ConcurrentHashMap<Integer, IoBuffer>();
private final Timer timer;
public HttpProtocolHandler() {
timer = new Timer(true);
}
public void exceptionCaught(IoSession session, Throwable cause)
throws Exception {
if (!(cause instanceof IOException)) {
cause.printStackTrace();
}
session.close();
}
public Dictionary extractParameters(Map hashParameters){
Dictionary parameters = new Hashtable();
Iterator it = hashParameters.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pair = (Map.Entry)it.next();
parameters.put(pair.getKey(), ((ArrayList) pair.getValue()).get(0) );
// it.remove(); // avoids a ConcurrentModificationException
}
return parameters;
}
public void messageReceived(IoSession session, Object message)
throws Exception {
HttpRequest req = (HttpRequest) message;
String path = req.getRequestUri().getPath(); //path: /echo
String end_point = path;
Dictionary parameters = this.extractParameters(req.getParameters());
String response = "";
/* switch (end_point) {
case "/io":
response= new IOHandler().handleRequest(parameters);
break;
case "/cpu":
response= new CPUHandler().handleRequest(parameters);
break;
case "/db":
response= new DBHandler().handleRequest(parameters);
break;
case "/memory":
response= new MemoryHandler().handleRequest(parameters);
break;
default:
response = "No end point found";
} */
response = "No end point found";
MutableHttpResponse res;
// if (path.startsWith("/size/")) {
// doDataResponse(session, req);
// } else if (path.startsWith("/delay/")) {
// doAsynchronousDelayedResponse(session, req);
// } else if (path.startsWith("/adelay/")) {
// doAsynchronousDelayedResponse(session, req);
// } else {
res = new DefaultHttpResponse();
IoBuffer bb = IoBuffer.allocate(1024);
bb.setAutoExpand(true);
bb.putString(response.toString(), Charset.forName("UTF-8").newEncoder());
bb.flip();
res.setContent(bb);
// res.setHeader("Pragma", "no-cache");
// res.setHeader("Cache-Control", "no-cache");
res.setStatus(HttpResponseStatus.OK);
WriteFuture future = session.write(res);
if (!HttpHeaderConstants.VALUE_KEEP_ALIVE.equalsIgnoreCase(
res.getHeader( HttpHeaderConstants.KEY_CONNECTION))) {
future.addListener(IoFutureListener.CLOSE);
}
}
private void writeResponse(IoSession session, HttpRequest req,
MutableHttpResponse res) {
res.normalize(req);
WriteFuture future = session.write(res);
if (!HttpHeaderConstants.VALUE_KEEP_ALIVE.equalsIgnoreCase(
res.getHeader( HttpHeaderConstants.KEY_CONNECTION))) {
future.addListener(IoFutureListener.CLOSE);
}
}
private void doDataResponse(IoSession session, HttpRequest req) {
String path = req.getRequestUri().getPath();
int size = Integer.parseInt(path.substring(path.lastIndexOf('/') + 1))
+ CONTENT_PADDING;
MutableHttpResponse res = new DefaultHttpResponse();
res.setStatus(HttpResponseStatus.OK);
res.setHeader("ETag", "W/\"" + size + "-1164091960000\"");
res.setHeader("Last-Modified", "Tue, 31 Nov 2006 06:52:40 GMT");
IoBuffer buf = buffers.get(size);
if (buf == null) {
buf = IoBuffer.allocate(size);
buffers.put(size, buf);
}
res.setContent(buf.duplicate());
writeResponse(session, req, res);
}
private void doAsynchronousDelayedResponse(final IoSession session,
final HttpRequest req) {
String path = req.getRequestUri().getPath();
int delay = Integer.parseInt(path.substring(path.lastIndexOf('/') + 1));
final MutableHttpResponse res = new DefaultHttpResponse();
res.setStatus(HttpResponseStatus.OK);
res.setHeader("ETag", "W/\"0-1164091960000\"");
res.setHeader("Last-Modified", "Tue, 31 Nov 2006 06:52:40 GMT");
timer.schedule(new TimerTask() {
@Override
public void run() {
writeResponse(session, req, res);
}
}, delay);
}
public void messageSent(IoSession session, Object message) throws Exception {
}
public void sessionClosed(IoSession session) throws Exception {
}
public void sessionCreated(IoSession session) throws Exception {
}
public void sessionIdle(IoSession session, IdleStatus status)
throws Exception {
session.close();
}
public void sessionOpened(IoSession session) throws Exception {
session.getConfig().setIdleTime(IdleStatus.BOTH_IDLE, 30);
}
}