farmwardeployer.java

精通tomcat书籍原代码,希望大家共同学习

/*
 * Copyright 1999,2004-2005 The Apache Software Foundation.
 *
 * 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.apache.catalina.ha.deploy;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import javax.management.MBeanServer;
import javax.management.ObjectName;

import org.apache.catalina.Context;
import org.apache.catalina.Engine;
import org.apache.catalina.Host;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.ha.CatalinaCluster;
import org.apache.catalina.ha.ClusterDeployer;
import org.apache.catalina.ha.ClusterListener;
import org.apache.catalina.ha.ClusterMessage;
import org.apache.catalina.tribes.Member;
import org.apache.commons.modeler.Registry;

/**
 * <p>
 * A farm war deployer is a class that is able to deploy/undeploy web
 * applications in WAR form within the cluster.
 * </p>
 * Any host can act as the admin, and will have three directories
 * <ul>
 * <li>deployDir - the directory where we watch for changes</li>
 * <li>applicationDir - the directory where we install applications</li>
 * <li>tempDir - a temporaryDirectory to store binary data when downloading a
 * war from the cluster</li>
 * </ul>
 * Currently we only support deployment of WAR files since they are easier to
 * send across the wire.
 * 
 * @author Filip Hanik
 * @author Peter Rossbach
 * @version $Revision: 390639 $
 */
public class FarmWarDeployer extends ClusterListener implements ClusterDeployer, FileChangeListener {
    /*--Static Variables----------------------------------------*/
    public static org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory
            .getLog(FarmWarDeployer.class);
    /**
     * The descriptive information about this implementation.
     */
    private static final String info = "FarmWarDeployer/1.2";

    /*--Instance Variables--------------------------------------*/
    protected CatalinaCluster cluster = null;

    protected boolean started = false; //default 5 seconds

    protected HashMap fileFactories = new HashMap();

    protected String deployDir;

    protected String tempDir;

    protected String watchDir;

    protected boolean watchEnabled = false;

    protected WarWatcher watcher = null;

    /**
     * Iteration count for background processing.
     */
    private int count = 0;

    /**
     * Frequency of the Farm watchDir check. Cluster wide deployment will be
     * done once for the specified amount of backgrondProcess calls (ie, the
     * lower the amount, the most often the checks will occur).
     */
    protected int processDeployFrequency = 2;

    /**
     * Path where context descriptors should be deployed.
     */
    protected File configBase = null;

    /**
     * The associated host.
     */
    protected Host host = null;

    /**
     * The host appBase.
     */
    protected File appBase = null;

    /**
     * MBean server.
     */
    protected MBeanServer mBeanServer = null;

    /**
     * The associated deployer ObjectName.
     */
    protected ObjectName oname = null;

    /*--Constructor---------------------------------------------*/
    public FarmWarDeployer() {
    }

    /**
     * Return descriptive information about this deployer implementation and the
     * corresponding version number, in the format
     * <code>&lt;description&gt;/&lt;version&gt;</code>.
     */
    public String getInfo() {

        return (info);

    }

    /*--Logic---------------------------------------------------*/
    public void start() throws Exception {
        if (started)
            return;
        getCluster().addClusterListener(this);
        if (watchEnabled) {
            watcher = new WarWatcher(this, new File(getWatchDir()));
            if (log.isInfoEnabled())
                log.info("Cluster deployment is watching " + getWatchDir()
                        + " for changes.");
        }

        // Check to correct engine and host setup
        host = (Host) getCluster().getContainer();
        Engine engine = (Engine) host.getParent();
        try {
            oname = new ObjectName(engine.getName() + ":type=Deployer,host="
                    + host.getName());
        } catch (Exception e) {
            log.error("Can't construct MBean object name" + e);
        }
        configBase = new File(System.getProperty("catalina.base"), "conf");
        if (engine != null) {
            configBase = new File(configBase, engine.getName());
        }
        if (host != null) {
            configBase = new File(configBase, host.getName());
        }

        // Retrieve the MBean server
        mBeanServer = Registry.getRegistry(null, null).getMBeanServer();

        started = true;
        count = 0;
        if (log.isInfoEnabled())
            log.info("Cluster FarmWarDeployer started.");
    }

    /*
     * stop cluster wide deployments
     * 
     * @see org.apache.catalina.cluster.ClusterDeployer#stop()
     */
    public void stop() throws LifecycleException {
        started = false;
        getCluster().removeClusterListener(this);
        count = 0;
        if (watcher != null) {
            watcher.clear();
            watcher = null;

        }
        if (log.isInfoEnabled())
            log.info("Cluster FarmWarDeployer stopped.");
    }

    public void cleanDeployDir() {
        throw new java.lang.UnsupportedOperationException(
                "Method cleanDeployDir() not yet implemented.");
    }

    /**
     * Callback from the cluster, when a message is received, The cluster will
     * broadcast it invoking the messageReceived on the receiver.
     * 
     * @param msg
     *            ClusterMessage - the message received from the cluster
     */
    public void messageReceived(ClusterMessage msg) {
        try {
            if (msg instanceof FileMessage && msg != null) {
                FileMessage fmsg = (FileMessage) msg;
                if (log.isDebugEnabled())
                    log.debug("receive cluster deployment [ path: "
                            + fmsg.getContextPath() + " war:  "
                            + fmsg.getFileName() + " ]");
                FileMessageFactory factory = getFactory(fmsg);
                // TODO correct second try after app is in service!
                if (factory.writeMessage(fmsg)) {
                    //last message received war file is completed
                    String name = factory.getFile().getName();
                    if (!name.endsWith(".war"))
                        name = name + ".war";
                    File deployable = new File(getDeployDir(), name);
                    try {
                        String path = fmsg.getContextPath();
                        if (!isServiced(path)) {
                            addServiced(path);
                            try {
                                remove(path);
                                factory.getFile().renameTo(deployable);
                                check(path);
                            } finally {
                                removeServiced(path);
                            }
                            if (log.isDebugEnabled())
                                log.debug("deployment from " + path
                                        + " finished.");
                        } else
                            log.error("Application " + path
                                    + " in used. touch war file " + name
                                    + " again!");
                    } catch (Exception ex) {
                        log.error(ex);
                    } finally {
                        removeFactory(fmsg);
                    }
                }
            } else if (msg instanceof UndeployMessage && msg != null) {
                try {
                    UndeployMessage umsg = (UndeployMessage) msg;
                    String path = umsg.getContextPath();
                    if (log.isDebugEnabled())
                        log.debug("receive cluster undeployment from " + path);
                    if (!isServiced(path)) {
                        addServiced(path);
                        try {
                            remove(path);
                        } finally {
                            removeServiced(path);
                        }
                        if (log.isDebugEnabled())
                            log.debug("undeployment from " + path
                                    + " finished.");
                    } else
                        log.error("Application "
                            + path
                            + " in used. Sorry not remove from backup cluster nodes!");
                } catch (Exception ex) {
                    log.error(ex);
                }
            }
        } catch (java.io.IOException x) {
            log.error("Unable to read farm deploy file message.", x);
        }
    }

    /**
     * create factory for all transported war files
     * 
     * @param msg
     * @return Factory for all app message (war files)
     * @throws java.io.FileNotFoundException
     * @throws java.io.IOException
     */
    public synchronized FileMessageFactory getFactory(FileMessage msg)
            throws java.io.FileNotFoundException, java.io.IOException {
        File tmpFile = new File(msg.getFileName());
        File writeToFile = new File(getTempDir(), tmpFile.getName());
        FileMessageFactory factory = (FileMessageFactory) fileFactories.get(msg
                .getFileName());
        if (factory == null) {
            factory = FileMessageFactory.getInstance(writeToFile, true);
            fileFactories.put(msg.getFileName(), factory);
        }
        return factory;
    }

    /**
     * Remove file (war) from messages)
     * 
     * @param msg
     */
    public void removeFactory(FileMessage msg) {
        fileFactories.remove(msg.getFileName());
    }

    /**
     * Before the cluster invokes messageReceived the cluster will ask the
     * receiver to accept or decline the message, In the future, when messages
     * get big, the accept method will only take a message header
     * 
     * @param msg
     *            ClusterMessage
     * @return boolean - returns true to indicate that messageReceived should be
     *         invoked. If false is returned, the messageReceived method will
     *         not be invoked.
     */
    public boolean accept(ClusterMessage msg) {
        return (msg instanceof FileMessage) || (msg instanceof UndeployMessage);
    }

    /**
     * Install a new web application, whose web application archive is at the
     * specified URL, into this container and all the other members of the
     * cluster with the specified context path. A context path of "" (the empty
     * string) should be used for the root application for this container.
     * Otherwise, the context path must start with a slash.
     * <p>
     * If this application is successfully installed locally, a ContainerEvent
     * of type <code>INSTALL_EVENT</code> will be sent to all registered
     * listeners, with the newly created <code>Context</code> as an argument.
     * 
     * @param contextPath
     *            The context path to which this application should be installed
     *            (must be unique)
     * @param war
     *            A URL of type "jar:" that points to a WAR file, or type
     *            "file:" that points to an unpacked directory structure
     *            containing the web application to be installed
     * 
     * @exception IllegalArgumentException
     *                if the specified context path is malformed (it must be ""
     *                or start with a slash)
     * @exception IllegalStateException
     *                if the specified context path is already attached to an
     *                existing web application
     * @exception IOException
     *                if an input/output error was encountered during
     *                installation
     */
    public void install(String contextPath, URL war) throws IOException {
        Member[] members = getCluster().getMembers();
        Member localMember = getCluster().getLocalMember();
        FileMessageFactory factory = FileMessageFactory.getInstance(new File(
                war.getFile()), false);
        FileMessage msg = new FileMessage(localMember, war.getFile(),
                contextPath);
        if(log.isDebugEnabled())
            log.debug("Send cluster war deployment [ path:"
                    + contextPath + " war: " + war + " ] started.");
        msg = factory.readMessage(msg);
        while (msg != null) {
            for (int i = 0; i < members.length; i++) {
                if (log.isDebugEnabled())
                    log.debug("Send cluster war fragment [ path: "
                            + contextPath + " war: " + war + " to: " +  members[i] + " ]");
                getCluster().send(msg, members[i]);
            }
            msg = factory.readMessage(msg);
        }
        if(log.isDebugEnabled())
            log.debug("Send cluster war deployment [ path: "
                    + contextPath + " war: " + war + " ] finished.");
    }

    /**