Tomcat example source code file (AjpProtocol.java)

This example Tomcat source code file (AjpProtocol.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

actionhook, ajpconnectionhandler, ajpprocessor, ajpprocessor, ajpprotocol, atomiclong, exception, exception, hashtable, management, net, network, objectname, objectname, requestinfo, string, string, threading, threads, util

The Tomcat AjpProtocol.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.coyote.ajp;

import java.net.InetAddress;
import java.net.Socket;
import java.net.URLEncoder;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.ObjectName;

import org.apache.coyote.ActionCode;
import org.apache.coyote.ActionHook;
import org.apache.coyote.Adapter;
import org.apache.coyote.ProtocolHandler;
import org.apache.coyote.RequestGroupInfo;
import org.apache.coyote.RequestInfo;
import org.apache.tomcat.util.modeler.Registry;
import org.apache.tomcat.util.net.JIoEndpoint;
import org.apache.tomcat.util.net.JIoEndpoint.Handler;
import org.apache.tomcat.util.res.StringManager;


/**
 * Abstract the protocol implementation, including threading, etc.
 * Processor is single threaded and specific to stream-based protocols,
 * will not fit Jk protocols like JNI.
 *
 * @author Remy Maucherat
 * @author Costin Manolache
 */
public class AjpProtocol 
    implements ProtocolHandler, MBeanRegistration {
    
    
    protected static org.apache.juli.logging.Log log =
        org.apache.juli.logging.LogFactory.getLog(AjpProtocol.class);

    /**
     * The string manager for this package.
     */
    protected static StringManager sm =
        StringManager.getManager(Constants.Package);


    // ------------------------------------------------------------ Constructor


    public AjpProtocol() {
        cHandler = new AjpConnectionHandler(this);
        setSoLinger(Constants.DEFAULT_CONNECTION_LINGER);
        setSoTimeout(Constants.DEFAULT_CONNECTION_TIMEOUT);
        //setServerSoTimeout(Constants.DEFAULT_SERVER_SOCKET_TIMEOUT);
        setTcpNoDelay(Constants.DEFAULT_TCP_NO_DELAY);
    }

    
    // ----------------------------------------------------- Instance Variables


    protected ObjectName tpOname;
    
    
    protected ObjectName rgOname;


    /**
     * Associated java.io endpoint.
     */
    protected JIoEndpoint endpoint = new JIoEndpoint();


    /**
     * Configuration attributes.
     */
    protected Hashtable attributes = new Hashtable();


    /**
     * Adapter which will process the requests recieved by this endpoint.
     */
    private Adapter adapter;
    
    
    /**
     * Connection handler for AJP.
     */
    private AjpConnectionHandler cHandler;


    // --------------------------------------------------------- Public Methods


    /** 
     * Pass config info
     */
    public void setAttribute(String name, Object value) {
        if (log.isTraceEnabled()) {
            log.trace(sm.getString("ajpprotocol.setattribute", name, value));
        }
        attributes.put(name, value);
    }

    public Object getAttribute(String key) {
        if (log.isTraceEnabled()) {
            log.trace(sm.getString("ajpprotocol.getattribute", key));
        }
        return attributes.get(key);
    }


    public Iterator getAttributeNames() {
        return attributes.keySet().iterator();
    }


    /**
     * The adapter, used to call the connector
     */
    public void setAdapter(Adapter adapter) {
        this.adapter = adapter;
    }


    public Adapter getAdapter() {
        return adapter;
    }


    /** Start the protocol
     */
    public void init() throws Exception {
        endpoint.setName(getName());
        endpoint.setHandler(cHandler);

        try {
            endpoint.init();
        } catch (Exception ex) {
            log.error(sm.getString("ajpprotocol.endpoint.initerror"), ex);
            throw ex;
        }
        if (log.isInfoEnabled()) {
            log.info(sm.getString("ajpprotocol.init", getName()));
        }
    }


    public void start() throws Exception {
        if (this.domain != null ) {
            try {
                tpOname = new ObjectName
                    (domain + ":" + "type=ThreadPool,name=" + getName());
                Registry.getRegistry(null, null)
                    .registerComponent(endpoint, tpOname, null );
            } catch (Exception e) {
                log.error("Can't register threadpool" );
            }
            rgOname = new ObjectName
                (domain + ":type=GlobalRequestProcessor,name=" + getName());
            Registry.getRegistry(null, null).registerComponent
                (cHandler.global, rgOname, null);
        }

        try {
            endpoint.start();
        } catch (Exception ex) {
            log.error(sm.getString("ajpprotocol.endpoint.starterror"), ex);
            throw ex;
        }
        if (log.isInfoEnabled())
            log.info(sm.getString("ajpprotocol.start", getName()));
    }

    public void pause() throws Exception {
        try {
            endpoint.pause();
        } catch (Exception ex) {
            log.error(sm.getString("ajpprotocol.endpoint.pauseerror"), ex);
            throw ex;
        }
        if (log.isInfoEnabled())
            log.info(sm.getString("ajpprotocol.pause", getName()));
    }

    public void resume() throws Exception {
        try {
            endpoint.resume();
        } catch (Exception ex) {
            log.error(sm.getString("ajpprotocol.endpoint.resumeerror"), ex);
            throw ex;
        }
        if (log.isInfoEnabled())
            log.info(sm.getString("ajpprotocol.resume", getName()));
    }

    public void destroy() throws Exception {
        if (log.isInfoEnabled())
            log.info(sm.getString("ajpprotocol.stop", getName()));
        endpoint.destroy();
        if (tpOname!=null)
            Registry.getRegistry(null, null).unregisterComponent(tpOname);
        if (rgOname != null)
            Registry.getRegistry(null, null).unregisterComponent(rgOname);
    }

    // *
    public String getName() {
        String encodedAddr = "";
        if (getAddress() != null) {
            encodedAddr = "" + getAddress();
            if (encodedAddr.startsWith("/"))
                encodedAddr = encodedAddr.substring(1);
            encodedAddr = URLEncoder.encode(encodedAddr) + "-";
        }
        return ("ajp-" + encodedAddr + endpoint.getPort());
    }

    /**
     * Processor cache.
     */
    protected int processorCache = -1;
    public int getProcessorCache() { return this.processorCache; }
    public void setProcessorCache(int processorCache) { this.processorCache = processorCache; }

    public Executor getExecutor() { return endpoint.getExecutor(); }
    public void setExecutor(Executor executor) { endpoint.setExecutor(executor); }
    
    public int getMaxThreads() { return endpoint.getMaxThreads(); }
    public void setMaxThreads(int maxThreads) { endpoint.setMaxThreads(maxThreads); }

    public int getThreadPriority() { return endpoint.getThreadPriority(); }
    public void setThreadPriority(int threadPriority) { endpoint.setThreadPriority(threadPriority); }

    public int getBacklog() { return endpoint.getBacklog(); }
    public void setBacklog(int backlog) { endpoint.setBacklog(backlog); }

    public int getPort() { return endpoint.getPort(); }
    public void setPort(int port) { endpoint.setPort(port); }

    public InetAddress getAddress() { return endpoint.getAddress(); }
    public void setAddress(InetAddress ia) { endpoint.setAddress(ia); }

    public boolean getTcpNoDelay() { return endpoint.getTcpNoDelay(); }
    public void setTcpNoDelay(boolean tcpNoDelay) { endpoint.setTcpNoDelay(tcpNoDelay); }

    public int getSoLinger() { return endpoint.getSoLinger(); }
    public void setSoLinger(int soLinger) { endpoint.setSoLinger(soLinger); }

    public int getSoTimeout() { return endpoint.getSoTimeout(); }
    public void setSoTimeout(int soTimeout) { endpoint.setSoTimeout(soTimeout); }

    /**
     * Should authentication be done in the native webserver layer, 
     * or in the Servlet container ?
     */
    protected boolean tomcatAuthentication = true;
    public boolean getTomcatAuthentication() { return tomcatAuthentication; }
    public void setTomcatAuthentication(boolean tomcatAuthentication) { this.tomcatAuthentication = tomcatAuthentication; }

    /**
     * Required secret.
     */
    protected String requiredSecret = null;
    public void setRequiredSecret(String requiredSecret) { this.requiredSecret = requiredSecret; }
    
    /**
     * AJP packet size.
     */
    protected int packetSize = Constants.MAX_PACKET_SIZE;
    public int getPacketSize() { return packetSize; }
    public void setPacketSize(int packetSize) { this.packetSize = packetSize; }

    
    /**
     * The number of seconds Tomcat will wait for a subsequent request
     * before closing the connection.
     */
    protected int keepAliveTimeout = -1;
    public int getKeepAliveTimeout() { return keepAliveTimeout; }
    public void setKeepAliveTimeout(int timeout) { keepAliveTimeout = timeout; }


    // --------------------------------------  AjpConnectionHandler Inner Class


    protected static class AjpConnectionHandler implements Handler {

        protected AjpProtocol proto;
        protected AtomicLong registerCount = new AtomicLong(0);
        protected RequestGroupInfo global = new RequestGroupInfo();

        protected ConcurrentLinkedQueue<AjpProcessor> recycledProcessors = 
            new ConcurrentLinkedQueue<AjpProcessor>() {
            protected AtomicInteger size = new AtomicInteger(0);
            public boolean offer(AjpProcessor processor) {
                boolean offer = (proto.processorCache == -1) ? true : (size.get() < proto.processorCache);
                //avoid over growing our cache or add after we have stopped
                boolean result = false;
                if ( offer ) {
                    result = super.offer(processor);
                    if ( result ) {
                        size.incrementAndGet();
                    }
                }
                if (!result) unregister(processor);
                return result;
            }
            
            public AjpProcessor poll() {
                AjpProcessor result = super.poll();
                if ( result != null ) {
                    size.decrementAndGet();
                }
                return result;
            }
            
            public void clear() {
                AjpProcessor next = poll();
                while ( next != null ) {
                    unregister(next);
                    next = poll();
                }
                super.clear();
                size.set(0);
            }
        };

        public AjpConnectionHandler(AjpProtocol proto) {
            this.proto = proto;
        }

        public boolean process(Socket socket) {
            AjpProcessor processor = recycledProcessors.poll();
            try {

                if (processor == null) {
                    processor = createProcessor();
                }

                if (processor instanceof ActionHook) {
                    ((ActionHook) processor).action(ActionCode.ACTION_START, null);
                }

                processor.process(socket);
                return false;

            } catch(java.net.SocketException e) {
                // SocketExceptions are normal
                AjpProtocol.log.debug
                    (sm.getString
                     ("ajpprotocol.proto.socketexception.debug"), e);
            } catch (java.io.IOException e) {
                // IOExceptions are normal
                AjpProtocol.log.debug
                    (sm.getString
                     ("ajpprotocol.proto.ioexception.debug"), e);
            }
            // Future developers: if you discover any other
            // rare-but-nonfatal exceptions, catch them here, and log as
            // above.
            catch (Throwable e) {
                // any other exception or error is odd. Here we log it
                // with "ERROR" level, so it will show up even on
                // less-than-verbose logs.
                AjpProtocol.log.error
                    (sm.getString("ajpprotocol.proto.error"), e);
            } finally {
                if (processor instanceof ActionHook) {
                    ((ActionHook) processor).action(ActionCode.ACTION_STOP, null);
                }
                recycledProcessors.offer(processor);
            }
            return false;
        }

        protected AjpProcessor createProcessor() {
            AjpProcessor processor = new AjpProcessor(proto.packetSize, proto.endpoint);
            processor.setAdapter(proto.adapter);
            processor.setTomcatAuthentication(proto.tomcatAuthentication);
            processor.setRequiredSecret(proto.requiredSecret);
            processor.setKeepAliveTimeout(proto.keepAliveTimeout);
            register(processor);
            return processor;
        }
        
        protected void register(AjpProcessor processor) {
            if (proto.getDomain() != null) {
                synchronized (this) {
                    try {
                        long count = registerCount.incrementAndGet();
                        RequestInfo rp = processor.getRequest().getRequestProcessor();
                        rp.setGlobalProcessor(global);
                        ObjectName rpName = new ObjectName
                            (proto.getDomain() + ":type=RequestProcessor,worker="
                                + proto.getName() + ",name=AjpRequest" + count);
                        if (log.isDebugEnabled()) {
                            log.debug("Register " + rpName);
                        }
                        Registry.getRegistry(null, null).registerComponent(rp, rpName, null);
                        rp.setRpName(rpName);
                    } catch (Exception e) {
                        log.warn("Error registering request");
                    }
                }
            }
        }

        protected void unregister(AjpProcessor processor) {
            if (proto.getDomain() != null) {
                synchronized (this) {
                    try {
                        RequestInfo rp = processor.getRequest().getRequestProcessor();
                        rp.setGlobalProcessor(null);
                        ObjectName rpName = rp.getRpName();
                        if (log.isDebugEnabled()) {
                            log.debug("Unregister " + rpName);
                        }
                        Registry.getRegistry(null, null).unregisterComponent(rpName);
                        rp.setRpName(null);
                    } catch (Exception e) {
                        log.warn("Error unregistering request", e);
                    }
                }
            }
        }

    }


    // -------------------- Various implementation classes --------------------


    protected String domain;
    protected ObjectName oname;
    protected MBeanServer mserver;

    public ObjectName getObjectName() {
        return oname;
    }

    public String getDomain() {
        return domain;
    }

    public ObjectName preRegister(MBeanServer server,
                                  ObjectName name) throws Exception {
        oname=name;
        mserver=server;
        domain=name.getDomain();
        return name;
    }

    public void postRegister(Boolean registrationDone) {
    }

    public void preDeregister() throws Exception {
    }

    public void postDeregister() {
    }
    
 
}