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Tomcat example source code file (ChannelUn.java)

This example Tomcat source code file (ChannelUn.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

apracceptor, aprconnection, error, exception, file, io, ioexception, ioexception, management, msg, msgcontext, msgcontext, net, network, objectname, objectname, string, string

The Tomcat ChannelUn.java source code

/*
 *  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.jk.common;

import java.net.URLEncoder;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.management.ObjectName;

import org.apache.jk.core.JkHandler;
import org.apache.jk.core.Msg;
import org.apache.jk.core.MsgContext;
import org.apache.jk.core.JkChannel;
import org.apache.jk.core.WorkerEnv;
import org.apache.coyote.Request;
import org.apache.coyote.RequestGroupInfo;
import org.apache.coyote.RequestInfo;
import org.apache.tomcat.util.modeler.Registry;
import org.apache.tomcat.util.threads.ThreadPool;
import org.apache.tomcat.util.threads.ThreadPoolRunnable;


/** Pass messages using unix domain sockets.
 *
 * @author Costin Manolache
 */
public class ChannelUn extends JniHandler implements JkChannel {
    static final int CH_OPEN=4;
    static final int CH_CLOSE=5;
    static final int CH_READ=6;
    static final int CH_WRITE=7;

    String file;
    ThreadPool tp = ThreadPool.createThreadPool(true);

    /* ==================== Tcp socket options ==================== */

    public ThreadPool getThreadPool() {
        return tp;
    }
    
    public void setFile( String f ) {
        file=f;
    }
    
    public String getFile() {
        return file;
    }
    
    /* ==================== ==================== */
    int socketNote=1;
    int isNote=2;
    int osNote=3;
    
    int localId=0;
    
    public void init() throws IOException {
        if( file==null ) {
            log.debug("No file, disabling unix channel");
            return;
            //throw new IOException( "No file for the unix socket channel");
        }
        if( wEnv!=null && wEnv.getLocalId() != 0 ) {
            localId=wEnv.getLocalId();
        }

        if( localId != 0 ) {
            file=file+ localId;
        }
        File socketFile=new File( file );
        if( !socketFile.isAbsolute() ) {
            String home=wEnv.getJkHome();
            if( home==null ) {
                log.debug("No jkhome");
            } else {
                File homef=new File( home );
                socketFile=new File( homef, file );
                log.debug( "Making the file absolute " +socketFile);
            }
        }
        
        if( ! socketFile.exists() ) {
            try {
                FileOutputStream fos=new FileOutputStream(socketFile);
                fos.write( 1 );
                fos.close();
            } catch( Throwable t ) {
                log.error("Attempting to create the file failed, disabling channel" 
                        + socketFile);
                return;
            }
        }
        // The socket file cannot be removed ...
        if (!socketFile.delete()) {
            log.error( "Can't remove socket file " + socketFile);
            return;
        }
        

        super.initNative( "channel.un:" + file );

        if( apr==null || ! apr.isLoaded() ) {
            log.debug("Apr is not available, disabling unix channel ");
            apr=null;
            return;
        }
        
        // Set properties and call init.
        setNativeAttribute( "file", file );
        // unixListenSocket=apr.unSocketListen( file, 10 );

        setNativeAttribute( "listen", "10" );
        // setNativeAttribute( "debug", "10" );

        // Initialize the thread pool and execution chain
        if( next==null && wEnv!=null ) {
            if( nextName!=null ) 
                setNext( wEnv.getHandler( nextName ) );
            if( next==null )
                next=wEnv.getHandler( "dispatch" );
            if( next==null )
                next=wEnv.getHandler( "request" );
        }

        super.initJkComponent();
        JMXRequestNote =wEnv.getNoteId( WorkerEnv.ENDPOINT_NOTE, "requestNote");        
        // Run a thread that will accept connections.
        if( this.domain != null ) {
            try {
                tpOName=new ObjectName(domain + ":type=ThreadPool,name=" + 
				       getChannelName());

                Registry.getRegistry(null, null)
		    .registerComponent(tp, tpOName, null);

		rgOName = new ObjectName
		    (domain+":type=GlobalRequestProcessor,name=" + getChannelName());
		Registry.getRegistry(null, null)
		    .registerComponent(global, rgOName, null);
            } catch (Exception e) {
                log.error("Can't register threadpool" );
            }
        }
        tp.start();
        AprAcceptor acceptAjp=new AprAcceptor(  this );
        tp.runIt( acceptAjp);
        log.info("JK: listening on unix socket: " + file );
        
    }

    ObjectName tpOName;
    ObjectName rgOName;
    RequestGroupInfo global=new RequestGroupInfo();
    int count = 0;
    int JMXRequestNote;

    public void start() throws IOException {
    }

    public void destroy() throws IOException {
        if( apr==null ) return;
        try {
            if( tp != null )
                tp.shutdown();
            
            //apr.unSocketClose( unixListenSocket,3);
            super.destroyJkComponent();

            if(tpOName != null) {
		Registry.getRegistry(null, null).unregisterComponent(tpOName);
	    }
	    if(rgOName != null) {
		Registry.getRegistry(null, null).unregisterComponent(rgOName);
	    }
        } catch(Exception e) {
            log.error("Error in destroy",e);
        }
    }

    public void registerRequest(Request req, MsgContext ep, int count) {
	if(this.domain != null) {
	    try {

		RequestInfo rp=req.getRequestProcessor();
		rp.setGlobalProcessor(global);
		ObjectName roname = new ObjectName
		    (getDomain() + ":type=RequestProcessor,worker="+
		     getChannelName()+",name=JkRequest" +count);
		ep.setNote(JMXRequestNote, roname);
                        
		Registry.getRegistry(null, null).registerComponent( rp, roname, null);
	    } catch( Exception ex ) {
		log.warn("Error registering request");
	    }
	}
    }


    /** Open a connection - since we're listening that will block in
        accept
    */
    public int open(MsgContext ep) throws IOException {
        // Will associate a jk_endpoint with ep and call open() on it.
        // jk_channel_un will accept a connection and set the socket info
        // in the endpoint. MsgContext will represent an active connection.
        return super.nativeDispatch( ep.getMsg(0), ep, CH_OPEN, 1 );
    }
    
    public void close(MsgContext ep) throws IOException {
        super.nativeDispatch( ep.getMsg(0), ep, CH_CLOSE, 1 );
    }

    public int send( Msg msg, MsgContext ep)
        throws IOException
    {
        return super.nativeDispatch( msg, ep, CH_WRITE, 0 );
    }

    public int receive( Msg msg, MsgContext ep )
        throws IOException
    {
        int rc=super.nativeDispatch( msg, ep, CH_READ, 1 );

        if( rc!=0 ) {
            log.error("receive error:   " + rc, new Throwable());
            return -1;
        }
        
        msg.processHeader();
        
        if (log.isDebugEnabled())
             log.debug("receive:  total read = " + msg.getLen());

	return msg.getLen();
    }

    public int flush( Msg msg, MsgContext ep) throws IOException {
	return OK;
    }

    public boolean isSameAddress( MsgContext ep ) {
	return false; // Not supporting shutdown on this channel.
    }

    boolean running=true;
    
    /** Accept incoming connections, dispatch to the thread pool
     */
    void acceptConnections() {
        if( apr==null ) return;

        if( log.isDebugEnabled() )
            log.debug("Accepting ajp connections on " + file);
        
        while( running ) {
            try {
                MsgContext ep=this.createMsgContext();

                // blocking - opening a server connection.
                int status=this.open(ep);
                if( status != 0 && status != 2 ) {
                    log.error( "Error acceptin connection on " + file );
                    break;
                }

                //    if( log.isDebugEnabled() )
                //     log.debug("Accepted ajp connections ");
        
                AprConnection ajpConn= new AprConnection(this, ep);
                tp.runIt( ajpConn );
            } catch( Exception ex ) {
                ex.printStackTrace();
            }
        }
    }

    /** Process a single ajp connection.
     */
    void processConnection(MsgContext ep) {
        if( log.isDebugEnabled() )
            log.debug( "New ajp connection ");
        try {
            MsgAjp recv=new MsgAjp();
            while( running ) {
                int res=this.receive( recv, ep );
                if( res<0 ) {
                    // EOS
                    break;
                }
                ep.setType(0);
                log.debug( "Process msg ");
                int status=next.invoke( recv, ep );
            }
            if( log.isDebugEnabled() )
                log.debug( "Closing un channel");
            try{
                Request req = (Request)ep.getRequest();
                if( req != null ) {
                    ObjectName roname = (ObjectName)ep.getNote(JMXRequestNote);
                    if( roname != null ) {
                        Registry.getRegistry(null, null).unregisterComponent(roname);
                    }
                    req.getRequestProcessor().setGlobalProcessor(null);
                }
            } catch( Exception ee) {
                log.error( "Error, releasing connection",ee);
            }
            this.close( ep );
        } catch( Exception ex ) {
            ex.printStackTrace();
        }
    }

    public int invoke( Msg msg, MsgContext ep ) throws IOException {
        int type=ep.getType();

        switch( type ) {
        case JkHandler.HANDLE_RECEIVE_PACKET:
            return receive( msg, ep );
        case JkHandler.HANDLE_SEND_PACKET:
            return send( msg, ep );
        case JkHandler.HANDLE_FLUSH:
            return flush( msg, ep );
        }

        // return next.invoke( msg, ep );
        return OK;
    }

    public String getChannelName() {
        String encodedAddr = "";
        String address = file;
        if (address != null) {
            encodedAddr = "" + address;
            if (encodedAddr.startsWith("/"))
                encodedAddr = encodedAddr.substring(1);
            encodedAddr = URLEncoder.encode(encodedAddr) ;
        }
        return ("jk-" + encodedAddr);
    }

    private static org.apache.juli.logging.Log log=
        org.apache.juli.logging.LogFactory.getLog( ChannelUn.class );
}

class AprAcceptor implements ThreadPoolRunnable {
    ChannelUn wajp;
    
    AprAcceptor(ChannelUn wajp ) {
        this.wajp=wajp;
    }

    public Object[] getInitData() {
        return null;
    }

    public void runIt(Object thD[]) {
        wajp.acceptConnections();
    }
}

class AprConnection implements ThreadPoolRunnable {
    ChannelUn wajp;
    MsgContext ep;

    AprConnection(ChannelUn wajp, MsgContext ep) {
        this.wajp=wajp;
        this.ep=ep;
    }


    public Object[] getInitData() {
        return null;
    }
    
    public void runIt(Object perTh[]) {
        wajp.processConnection(ep);
    }
}

Other Tomcat examples (source code examples)

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