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Tomcat example source code file (FarmWarDeployer.java)

This example Tomcat source code file (FarmWarDeployer.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

exception, exception, farmwardeployer, file, file, filemessage, filemessage, filemessagefactory, io, ioexception, management, net, network, send, string, string, unable, undeploymessage, util

The Tomcat FarmWarDeployer.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.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.Container;
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.tomcat.util.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>applicationDir - the directory where we install applications
 * <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: 613809 $
 */
public class FarmWarDeployer extends ClusterListener implements ClusterDeployer, FileChangeListener {
    /*--Static Variables----------------------------------------*/
    public static org.apache.juli.logging.Log log = org.apache.juli.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><description>/<version>.
     */
    public String getInfo() {

        return (info);

    }

    /*--Logic---------------------------------------------------*/
    public void start() throws Exception {
        if (started)
            return;
        Container hcontainer = getCluster().getContainer();
        if(!(hcontainer instanceof Host)) {
            log.error("FarmWarDeployer can only work as host cluster subelement!");
            return ;
        }
        host = (Host) hcontainer;
    
        // Check to correct engine and host setup
        Container econtainer = host.getParent();
        if(econtainer == null && econtainer instanceof Engine) {
            log.error("FarmWarDeployer can only work if parent of " + host.getName()+ " is an engine!"); 
            return ;
        }
        Engine engine = (Engine) econtainer;
        String hostname = null;
        hostname = host.getName();
        try {
            oname = new ObjectName(engine.getName() + ":type=Deployer,host="
                    + hostname);
        } catch (Exception e) {
            log.error("Can't construct MBean object name" + e);
            return;
        }
        if (watchEnabled) {
            watcher = new WarWatcher(this, new File(getWatchDir()));
            if (log.isInfoEnabled()) {
                log.info("Cluster deployment is watching " + getWatchDir()
                          + " for changes.");
            }
        }
         
        configBase = new File(System.getProperty("catalina.base"), "conf");
        if (engine != null) {
            configBase = new File(configBase, engine.getName());
        } 
        if (host != null) {
            configBase = new File(configBase, hostname);
        }

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

        started = true;
        count = 0;

        getCluster().addClusterListener(this);

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

    /*
     * stop cluster wide deployments
     * 
     * @see org.apache.catalina.ha.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 will be sent to all registered
     * listeners, with the newly created <code>Context 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.");
    }

    /**
     * Remove an existing web application, attached to the specified context
     * path. If this application is successfully removed, a ContainerEvent of
     * type <code>REMOVE_EVENT will be sent to all registered
     * listeners, with the removed <code>Context as an argument.
     * Deletes the web application war file and/or directory if they exist in
     * the Host's appBase.
     * 
     * @param contextPath
     *            The context path of the application to be removed
     * @param undeploy
     *            boolean flag to remove web application from server
     * 
     * @exception IllegalArgumentException
     *                if the specified context path is malformed (it must be ""
     *                or start with a slash)
     * @exception IllegalArgumentException
     *                if the specified context path does not identify a
     *                currently installed web application
     * @exception IOException
     *                if an input/output error occurs during removal
     */
    public void remove(String contextPath, boolean undeploy) throws IOException {
        if (log.isInfoEnabled())
            log.info("Cluster wide remove of web app " + contextPath);
        Member localMember = getCluster().getLocalMember();
        UndeployMessage msg = new UndeployMessage(localMember, System
                .currentTimeMillis(), "Undeploy:" + contextPath + ":"
                + System.currentTimeMillis(), contextPath, undeploy);
        if (log.isDebugEnabled())
            log.debug("Send cluster wide undeployment from "
                    + contextPath );
        cluster.send(msg);
        // remove locally
        if (undeploy) {
            try {
                if (!isServiced(contextPath)) {
                    addServiced(contextPath);
                    try {
                        remove(contextPath);
                    } finally {
                        removeServiced(contextPath);
                    }
                } else
                    log.error("Local remove from " + contextPath
                            + "failed, other manager has app in service!");

            } catch (Exception ex) {
                log.error("local remove from " + contextPath + " failed", ex);
            }
        }

    }

    /*
     * Modifcation from watchDir war detected!
     * 
     * @see org.apache.catalina.ha.deploy.FileChangeListener#fileModified(java.io.File)
     */
    public void fileModified(File newWar) {
        try {
            File deployWar = new File(getDeployDir(), newWar.getName());
            copy(newWar, deployWar);
            String contextName = getContextName(deployWar);
            if (log.isInfoEnabled())
                log.info("Installing webapp[" + contextName + "] from "
                        + deployWar.getAbsolutePath());
            try {
                remove(contextName, false);
            } catch (Exception x) {
                log.error("No removal", x);
            }
            install(contextName, deployWar.toURL());
        } catch (Exception x) {
            log.error("Unable to install WAR file", x);
        }
    }

    /*
     * War remvoe from watchDir
     * 
     * @see org.apache.catalina.ha.deploy.FileChangeListener#fileRemoved(java.io.File)
     */
    public void fileRemoved(File removeWar) {
        try {
            String contextName = getContextName(removeWar);
            if (log.isInfoEnabled())
                log.info("Removing webapp[" + contextName + "]");
            remove(contextName, true);
        } catch (Exception x) {
            log.error("Unable to remove WAR file", x);
        }
    }

    /**
     * Create a context path from war
     * @param war War filename
     * @return '/filename' or if war name is ROOT.war context name is empty string '' 
     */
    protected String getContextName(File war) {
        String contextName = "/"
        + war.getName().substring(0,
                war.getName().lastIndexOf(".war"));
        if("/ROOT".equals(contextName))
            contextName= "" ;
        return contextName ;
    }
    
    /**
     * Given a context path, get the config file name.
     */
    protected String getConfigFile(String path) {
        String basename = null;
        if (path.equals("")) {
            basename = "ROOT";
        } else {
            basename = path.substring(1).replace('/', '#');
        }
        return (basename);
    }

    /**
     * Given a context path, get the config file name.
     */
    protected String getDocBase(String path) {
        String basename = null;
        if (path.equals("")) {
            basename = "ROOT";
        } else {
            basename = path.substring(1);
        }
        return (basename);
    }

    /**
     * Return a File object representing the "application root" directory for
     * our associated Host.
     */
    protected File getAppBase() {

        if (appBase != null) {
            return appBase;
        }

        File file = new File(host.getAppBase());
        if (!file.isAbsolute())
            file = new File(System.getProperty("catalina.base"), host
                    .getAppBase());
        try {
            appBase = file.getCanonicalFile();
        } catch (IOException e) {
            appBase = file;
        }
        return (appBase);

    }

    /**
     * Invoke the remove method on the deployer.
     */
    protected void remove(String path) throws Exception {
        // TODO Handle remove also work dir content !
        // Stop the context first to be nicer
        Context context = (Context) host.findChild(path);
        if (context != null) {
            if(log.isDebugEnabled())
                log.debug("Undeploy local context " +path );
            ((Lifecycle) context).stop();
            File war = new File(getAppBase(), getDocBase(path) + ".war");
            File dir = new File(getAppBase(), getDocBase(path));
            File xml = new File(configBase, getConfigFile(path) + ".xml");
            if (war.exists()) {
                war.delete();
            } else if (dir.exists()) {
                undeployDir(dir);
            } else {
                xml.delete();
            }
            // Perform new deployment and remove internal HostConfig state
            check(path);
        }

    }

    /**
     * Delete the specified directory, including all of its contents and
     * subdirectories recursively.
     * 
     * @param dir
     *            File object representing the directory to be deleted
     */
    protected void undeployDir(File dir) {

        String files[] = dir.list();
        if (files == null) {
            files = new String[0];
        }
        for (int i = 0; i < files.length; i++) {
            File file = new File(dir, files[i]);
            if (file.isDirectory()) {
                undeployDir(file);
            } else {
                file.delete();
            }
        }
        dir.delete();

    }

    /*
     * Call watcher to check for deploy changes
     * 
     * @see org.apache.catalina.ha.ClusterDeployer#backgroundProcess()
     */
    public void backgroundProcess() {
        if (started) {
            count = (count + 1) % processDeployFrequency;
            if (count == 0 && watchEnabled) {
                watcher.check();
            }
        }

    }

    /*--Deployer Operations ------------------------------------*/

    /**
     * Invoke the check method on the deployer.
     */
    protected void check(String name) throws Exception {
        String[] params = { name };
        String[] signature = { "java.lang.String" };
        mBeanServer.invoke(oname, "check", params, signature);
    }

    /**
     * Invoke the check method on the deployer.
     */
    protected boolean isServiced(String name) throws Exception {
        String[] params = { name };
        String[] signature = { "java.lang.String" };
        Boolean result = (Boolean) mBeanServer.invoke(oname, "isServiced",
                params, signature);
        return result.booleanValue();
    }

    /**
     * Invoke the check method on the deployer.
     */
    protected void addServiced(String name) throws Exception {
        String[] params = { name };
        String[] signature = { "java.lang.String" };
        mBeanServer.invoke(oname, "addServiced", params, signature);
    }

    /**
     * Invoke the check method on the deployer.
     */
    protected void removeServiced(String name) throws Exception {
        String[] params = { name };
        String[] signature = { "java.lang.String" };
        mBeanServer.invoke(oname, "removeServiced", params, signature);
    }

    /*--Instance Getters/Setters--------------------------------*/
    public CatalinaCluster getCluster() {
        return cluster;
    }

    public void setCluster(CatalinaCluster cluster) {
        this.cluster = cluster;
    }

    public boolean equals(Object listener) {
        return super.equals(listener);
    }

    public int hashCode() {
        return super.hashCode();
    }

    public String getDeployDir() {
        return deployDir;
    }

    public void setDeployDir(String deployDir) {
        this.deployDir = deployDir;
    }

    public String getTempDir() {
        return tempDir;
    }

    public void setTempDir(String tempDir) {
        this.tempDir = tempDir;
    }

    public String getWatchDir() {
        return watchDir;
    }

    public void setWatchDir(String watchDir) {
        this.watchDir = watchDir;
    }

    public boolean isWatchEnabled() {
        return watchEnabled;
    }

    public boolean getWatchEnabled() {
        return watchEnabled;
    }

    public void setWatchEnabled(boolean watchEnabled) {
        this.watchEnabled = watchEnabled;
    }

    /**
     * Return the frequency of watcher checks.
     */
    public int getProcessDeployFrequency() {

        return (this.processDeployFrequency);

    }

    /**
     * Set the watcher checks frequency.
     * 
     * @param processExpiresFrequency
     *            the new manager checks frequency
     */
    public void setProcessDeployFrequency(int processExpiresFrequency) {

        if (processExpiresFrequency <= 0) {
            return;
        }
        this.processDeployFrequency = processExpiresFrequency;
    }

    /**
     * Copy a file to the specified temp directory.
     * @param from copy from temp
     * @param to   to host appBase directory
     * @return true, copy successful
     */
    protected boolean copy(File from, File to) {
        try {
            if (!to.exists())
                to.createNewFile();
            java.io.FileInputStream is = new java.io.FileInputStream(from);
            java.io.FileOutputStream os = new java.io.FileOutputStream(to,
                    false);
            byte[] buf = new byte[4096];
            while (true) {
                int len = is.read(buf);
                if (len < 0)
                    break;
                os.write(buf, 0, len);
            }
            is.close();
            os.close();
        } catch (IOException e) {
            log.error("Unable to copy file from:" + from + " to:" + to, e);
            return false;
        }
        return true;
    }

}

Other Tomcat examples (source code examples)

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