NoClassDefFoundError and Netty
- by Dmytro Leonenko
Hi.
First to say I'm n00b in Java. I can understand most concepts but in my situation I want somebody to help me. I'm using JBoss Netty to handle simple http request and using MemCachedClient check existence of client ip in memcached.
import org.jboss.netty.channel.ChannelHandler;
import static org.jboss.netty.handler.codec.http.HttpHeaders.*;
import static org.jboss.netty.handler.codec.http.HttpHeaders.Names.*;
import static org.jboss.netty.handler.codec.http.HttpResponseStatus.*;
import static org.jboss.netty.handler.codec.http.HttpVersion.*;
import com.danga.MemCached.*;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.handler.codec.http.Cookie;
import org.jboss.netty.handler.codec.http.CookieDecoder;
import org.jboss.netty.handler.codec.http.CookieEncoder;
import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
import org.jboss.netty.handler.codec.http.HttpChunk;
import org.jboss.netty.handler.codec.http.HttpChunkTrailer;
import org.jboss.netty.handler.codec.http.HttpRequest;
import org.jboss.netty.handler.codec.http.HttpResponse;
import org.jboss.netty.handler.codec.http.HttpResponseStatus;
import org.jboss.netty.handler.codec.http.QueryStringDecoder;
import org.jboss.netty.util.CharsetUtil;
/**
* @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
* @author Andy Taylor ([email protected])
* @author <a href="http://gleamynode.net/">Trustin Lee</a>
*
* @version $Rev: 2368 $, $Date: 2010-10-18 17:19:03 +0900 (Mon, 18 Oct 2010) $
*/
@SuppressWarnings({"ALL"})
public class HttpRequestHandler extends SimpleChannelUpstreamHandler {
private HttpRequest request;
private boolean readingChunks;
/** Buffer that stores the response content */
private final StringBuilder buf = new StringBuilder();
protected MemCachedClient mcc = new MemCachedClient();
private static SockIOPool poolInstance = null;
static {
// server list and weights
String[] servers =
{
"lcalhost:11211"
};
//Integer[] weights = { 3, 3, 2 };
Integer[] weights = {1};
// grab an instance of our connection pool
SockIOPool pool = SockIOPool.getInstance();
// set the servers and the weights
pool.setServers(servers);
pool.setWeights(weights);
// set some basic pool settings
// 5 initial, 5 min, and 250 max conns
// and set the max idle time for a conn
// to 6 hours
pool.setInitConn(5);
pool.setMinConn(5);
pool.setMaxConn(250);
pool.setMaxIdle(21600000); //1000 * 60 * 60 * 6
// set the sleep for the maint thread
// it will wake up every x seconds and
// maintain the pool size
pool.setMaintSleep(30);
// set some TCP settings
// disable nagle
// set the read timeout to 3 secs
// and don't set a connect timeout
pool.setNagle(false);
pool.setSocketTO(3000);
pool.setSocketConnectTO(0);
// initialize the connection pool
pool.initialize();
// lets set some compression on for the client
// compress anything larger than 64k
//mcc.setCompressEnable(true);
//mcc.setCompressThreshold(64 * 1024);
}
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
HttpRequest request = this.request = (HttpRequest) e.getMessage();
if(mcc.get(request.getHeader("X-Real-Ip")) != null)
{
HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
response.setHeader("X-Accel-Redirect", request.getUri());
ctx.getChannel().write(response).addListener(ChannelFutureListener.CLOSE);
}
else {
sendError(ctx, NOT_FOUND);
}
}
private void writeResponse(MessageEvent e) {
// Decide whether to close the connection or not.
boolean keepAlive = isKeepAlive(request);
// Build the response object.
HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
response.setContent(ChannelBuffers.copiedBuffer(buf.toString(), CharsetUtil.UTF_8));
response.setHeader(CONTENT_TYPE, "text/plain; charset=UTF-8");
if (keepAlive) {
// Add 'Content-Length' header only for a keep-alive connection.
response.setHeader(CONTENT_LENGTH, response.getContent().readableBytes());
}
// Encode the cookie.
String cookieString = request.getHeader(COOKIE);
if (cookieString != null) {
CookieDecoder cookieDecoder = new CookieDecoder();
Set<Cookie> cookies = cookieDecoder.decode(cookieString);
if(!cookies.isEmpty()) {
// Reset the cookies if necessary.
CookieEncoder cookieEncoder = new CookieEncoder(true);
for (Cookie cookie : cookies) {
cookieEncoder.addCookie(cookie);
}
response.addHeader(SET_COOKIE, cookieEncoder.encode());
}
}
// Write the response.
ChannelFuture future = e.getChannel().write(response);
// Close the non-keep-alive connection after the write operation is done.
if (!keepAlive) {
future.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
throws Exception {
e.getCause().printStackTrace();
e.getChannel().close();
}
private void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) {
HttpResponse response = new DefaultHttpResponse(HTTP_1_1, status);
response.setHeader(CONTENT_TYPE, "text/plain; charset=UTF-8");
response.setContent(ChannelBuffers.copiedBuffer(
"Failure: " + status.toString() + "\r\n",
CharsetUtil.UTF_8));
// Close the connection as soon as the error message is sent.
ctx.getChannel().write(response).addListener(ChannelFutureListener.CLOSE);
}
}
When I try to send request like http://127.0.0.1:8090/1/2/3
I'm getting
java.lang.NoClassDefFoundError: com/danga/MemCached/MemCachedClient
at httpClientValidator.server.HttpRequestHandler.<clinit>(HttpRequestHandler.java:66)
I believe it's not related to classpath. May be it's related to context in which mcc doesn't exist.
Any help appreciated
EDIT:
Original code http://docs.jboss.org/netty/3.2/xref/org/jboss/netty/example/http/snoop/package-summary.html
I've modified some parts to fit my needs.
