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Tomcat example source code file (JkMain.java)

This example Tomcat source code file (JkMain.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

error, exception, exception, file, io, ioexception, jkmain, management, object, object, objectname, objectname, printstream, string, string, util, vector

The Tomcat JkMain.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.server;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
import java.util.StringTokenizer;
import java.util.Vector;

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

import org.apache.jk.core.JkHandler;
import org.apache.jk.core.WorkerEnv;
import org.apache.tomcat.util.IntrospectionUtils;
import org.apache.tomcat.util.modeler.Registry;

/** Main class used to startup and configure jk. It manages the conf/jk2.properties file
 *  and is the target of JMX proxy.
 *
 *  It implements a policy of save-on-change - whenever a property is changed at
 *  runtime the jk2.properties file will be overriden. 
 *
 *  You can edit the config file when tomcat is stoped ( or if you don't use JMX or
 *  other admin tools ).
 *
 *  The format of jk2.properties:
 *  <dl>
 *   <dt>TYPE[.LOCALNAME].PROPERTY_NAME=VALUE
 *   <dd>Set a property on the associated component. TYPE will be used to
 *   find the class name and instantiate the component. LOCALNAME allows
 *   multiple instances. In JMX mode, TYPE and LOCALNAME will form the
 *   JMX name ( eventually combined with a 'jk2' component )
 *
 *   <dt>NAME=VALUE
 *   <dd>Define global properties to be used in ${} substitutions
 *
 *   <dt>class.COMPONENT_TYPE=JAVA_CLASS_NAME
 *   <dd>Adds a new 'type' of component. We predefine all known types.
 * </dl>
 *
 * Instances are created the first time a component name is found. In addition,
 * 'handler.list' property will override the list of 'default' components that are
 * loaded automatically.
 *
 *  Note that the properties file is just one (simplistic) way to configure jk. We hope
 *  to see configs based on registry, LDAP, db, etc. ( XML is not necesarily better )
 * 
 * @author Costin Manolache
 */
public class JkMain implements MBeanRegistration
{
    WorkerEnv wEnv;
    String propFile;
    Properties props=new Properties();

    Properties modules=new Properties();
    boolean modified=false;
    boolean started=false;
    boolean saveProperties=false;

    public JkMain()
    {
        JkMain.jkMain=this;
        modules.put("channelSocket", "org.apache.jk.common.ChannelSocket");
        modules.put("channelNioSocket", "org.apache.jk.common.ChannelNioSocket");
        modules.put("channelUnix", "org.apache.jk.common.ChannelUn");
        modules.put("channelJni", "org.apache.jk.common.ChannelJni");
        modules.put("apr", "org.apache.jk.apr.AprImpl");
        modules.put("mx", "org.apache.jk.common.JkMX");
        modules.put("modeler", "org.apache.jk.common.JkModeler");
        modules.put("shm", "org.apache.jk.common.Shm");
        modules.put("request","org.apache.jk.common.HandlerRequest");
        modules.put("container","org.apache.jk.common.HandlerRequest");
        modules.put("modjk","org.apache.jk.common.ModJkMX");

    }

    public static JkMain getJkMain() {
        return jkMain;
    }

    private static String DEFAULT_HTTPS="com.sun.net.ssl.internal.www.protocol";
    private void initHTTPSUrls() {
        try {
            // 11657: if only ajp is used, https: redirects need to work ( at least for 1.3+)
            String value = System.getProperty("java.protocol.handler.pkgs");
            if (value == null) {
                value = DEFAULT_HTTPS;
            } else if (value.indexOf(DEFAULT_HTTPS) >= 0  ) {
                return; // already set
            } else {
                value += "|" + DEFAULT_HTTPS;
            }
            System.setProperty("java.protocol.handler.pkgs", value);
        } catch(Exception ex ) {
            log.info("Error adding SSL Protocol Handler",ex);
        }
    }

    // -------------------- Setting --------------------
    
    /** Load a .properties file into and set the values
     *  into jk2 configuration.
     */
    public void setPropertiesFile( String p  ) {
        propFile=p;
        if( started ) {
            loadPropertiesFile();
        }
    }

    public String getPropertiesFile() {
        return propFile;
    }

    public void setSaveProperties( boolean b ) {
        saveProperties=b;
    }

    /** Set a name/value as a jk2 property
     */
    public void setProperty( String n, String v ) {
        if( "jkHome".equals( n ) ) {
            setJkHome( v );
        } 
        if( "propertiesFile".equals( n ) ) {
            setPropertiesFile( v );
        }
        props.put( n, v );
        if( started ) {
            processProperty( n, v );
            saveProperties();
        }
    }
    /**
     * Retrieve a property.
     */
    public Object getProperty(String name) {
        String alias = (String)replacements.get(name);
        Object result = null;
        if(alias != null) {
            result = props.get(alias);
        }
        if(result == null) {
            result = props.get(name);
        }
        return result;
    }
    /**
     * Set the <code>channelClassName that will used to connect to
     * httpd.
     */
    public void setChannelClassName(String name) {
        props.put( "handler.channel.className",name);
    }

    public String getChannelClassName() {
        return (String)props.get( "handler.channel.className");
    }

    /**
     * Set the <code>workerClassName that will handle the request.
     * ( sort of 'pivot' in axis :-)
     */
    public void setWorkerClassName(String name) {
        props.put( "handler.container.className",name);
    }

    public String getWorkerClassName() {
        return (String)props.get( "handler.container.className");
    }

    /** Set the base dir of jk2. ( including WEB-INF if in a webapp ).
     *  We'll try to guess it from classpath if none is set ( for
     *  example on command line ), but if in a servlet environment
     *  you need to use Context.getRealPath or a system property or
     *  set it expliciltey.
     */
    public void setJkHome( String s ) {
        getWorkerEnv().setJkHome(s);
    }

    public String getJkHome() {
        return getWorkerEnv().getJkHome();
    }

    String out;
    String err;
    File propsF;
    
    public void setOut( String s ) {
        this.out=s;
    }

    public String getOut() {
        return this.out;
    }

    public void setErr( String s ) {
        this.err=s;
    }
    
    public String getErr() {
        return this.err;
    }
    
    // -------------------- Initialization --------------------
    
    public void init() throws IOException
    {
        long t1=System.currentTimeMillis();
        if(null != out) {
            PrintStream outS=new PrintStream(new FileOutputStream(out));
            System.setOut(outS);
        }
        if(null != err) {
            PrintStream errS=new PrintStream(new FileOutputStream(err));
            System.setErr(errS);
        }

        String home=getWorkerEnv().getJkHome();
        if( home==null ) {
            // XXX use IntrospectionUtil to find myself
            this.guessHome();
        }
        home=getWorkerEnv().getJkHome();
        if( home==null ) {
            log.info( "Can't find home, jk2.properties not loaded");
        }
        if(log.isDebugEnabled())
            log.debug("Starting Jk2, base dir= " + home  );
        loadPropertiesFile();

        String initHTTPS = (String)props.get("class.initHTTPS");
        if("true".equalsIgnoreCase(initHTTPS)) {
            initHTTPSUrls();
        }

        long t2=System.currentTimeMillis();
        initTime=t2-t1;
    }
    
    static String defaultHandlers[]= { "request",
                                       "container",
                                       "channelSocket"};
    /*
     static String defaultHandlers[]= { "apr",
                                       "shm",
                                       "request",
                                       "container",
                                       "channelSocket",
                                       "channelJni",
                                       "channelUnix"};
    */
    
    public void stop() 
    {
        for( int i=0; i<wEnv.getHandlerCount(); i++ ) {
            if( wEnv.getHandler(i) != null ) {
                try {
                    wEnv.getHandler(i).destroy();
                } catch( IOException ex) {
                    log.error("Error stopping " + wEnv.getHandler(i).getName(), ex);
                }
            }
        }

        started=false;
    }
    
    public void start() throws IOException
    {
        long t1=System.currentTimeMillis();
        // We must have at least 3 handlers:
        // channel is the 'transport'
        // request is the request processor or 'global' chain
        // container is the 'provider'
        // Additional handlers may exist and be used internally
        // or be chained to create one of the standard handlers 

        String handlers[]=defaultHandlers;
        // backward compat
        String workers=props.getProperty( "handler.list", null );
        if( workers!=null ) {
            handlers= split( workers, ",");
        }

        // Load additional component declarations
        processModules();
        
        for( int i=0; i<handlers.length; i++ ) {
            String name= handlers[i];
            JkHandler w=getWorkerEnv().getHandler( name );
            if( w==null ) {
                newHandler( name, "", name );
            }
        }

        // Process properties - and add aditional handlers.
        processProperties();

        for( int i=0; i<wEnv.getHandlerCount(); i++ ) {
            if( wEnv.getHandler(i) != null ) {
                try {
                    wEnv.getHandler(i).init();
                } catch( IOException ex) {
                    if( "apr".equals(wEnv.getHandler(i).getName() )) {
                        log.info( "APR not loaded, disabling jni components: " + ex.toString());
                    } else {
                        log.error( "error initializing " + wEnv.getHandler(i).getName(), ex );
                    }
                }
            }
        }

        started=true;
        long t2=System.currentTimeMillis();
        startTime=t2-t1;

        this.saveProperties();
        log.info("Jk running ID=" + wEnv.getLocalId() + " time=" + initTime + "/" + startTime +
                 "  config=" + propFile);
    }

    // -------------------- Usefull methods --------------------
    
    public WorkerEnv getWorkerEnv() {
        if( wEnv==null ) { 
            wEnv=new WorkerEnv();
        }
        return wEnv;
    }

    public void setWorkerEnv(WorkerEnv wEnv) {
        this.wEnv = wEnv;
    }

    /* A bit of magic to support workers.properties without giving
       up the clean get/set
    */
    public void setBeanProperty( Object target, String name, String val ) {
        if( val!=null )
            val=IntrospectionUtils.replaceProperties( val, props, null );
        if( log.isDebugEnabled())
            log.debug( "setProperty " + target + " " + name + "=" + val );
        
        IntrospectionUtils.setProperty( target, name, val );
    }

    /* 
     * Set a handler property
     */
    public void setPropertyString( String handlerN, String name, String val ) {
        if( log.isDebugEnabled() )
            log.debug( "setProperty " + handlerN + " " + name + "=" + val );
        Object target=getWorkerEnv().getHandler( handlerN );

        setBeanProperty( target, name, val );
        if( started ) {
            saveProperties();
        }

    }

    /** The time it took to initialize jk ( ms)
     */
    public long getInitTime() {
        return initTime;
    }

    /** The time it took to start jk ( ms )
     */
    public long getStartTime() {
        return startTime;
    }
    
    // -------------------- Main --------------------

    long initTime;
    long startTime;
    static JkMain jkMain=null;

    public static void main(String args[]) {
        try {
            if( args.length == 1 &&
                ( "-?".equals(args[0]) || "-h".equals( args[0])) ) {
                System.out.println("Usage: ");
                System.out.println("  JkMain [args]");
                System.out.println();
                System.out.println("  Each bean setter corresponds to an arg ( like -debug 10 )");
                System.out.println("  System properties:");
                System.out.println("    jk2.home    Base dir of jk2");
                return;
            }

            jkMain=new JkMain();

            IntrospectionUtils.processArgs( jkMain, args, new String[] {},
                                            null, new Hashtable());

            jkMain.init();
            jkMain.start();
        } catch( Exception ex ) {
            log.warn("Error running",ex);
        }
    }

    // -------------------- Private methods --------------------


    private boolean checkPropertiesFile() {
        if(propFile == null) {
            return false;
        }
        propsF = new File(propFile);
        if(!propsF.isAbsolute()) {
            String home = getWorkerEnv().getJkHome();
            if( home == null ) {
                return false;
            }
            propsF = new File(home, propFile);
        }
        return propsF.exists();
    }
            
    private void loadPropertiesFile() {
        if(!checkPropertiesFile()) {
            return;
        }

        try {
            props.load( new FileInputStream(propsF) );
        } catch(IOException ex ){
            log.warn("Unable to load properties from "+propsF,ex);
        }
    }

    public  void saveProperties() {
        if( !saveProperties) return;
        
        if(propsF == null) {
            log.warn("No properties file specified. Unable to save");
            return;
        }
        // Temp - to check if it works
        File outFile= new File(propsF.getParentFile(), propsF.getName()+".save");
        log.debug("Saving properties " + outFile );
        try {
            props.store( new FileOutputStream(outFile), "AUTOMATICALLY GENERATED" );
        } catch(IOException ex ){
            log.warn("Unable to save to "+outFile,ex);
        }
    }

    // translate top-level keys ( from coyote or generic ) into component keys
    static Hashtable replacements=new Hashtable();
    static {
        replacements.put("port","channelSocket.port");
        replacements.put("maxThreads", "channelSocket.maxThreads");   
        replacements.put("minSpareThreads", "channelSocket.minSpareThreads");   
        replacements.put("maxSpareThreads", "channelSocket.maxSpareThreads");   
        replacements.put("backlog", "channelSocket.backlog");   
        replacements.put("tcpNoDelay", "channelSocket.tcpNoDelay");
        replacements.put("soTimeout", "channelSocket.soTimeout");
        replacements.put("timeout", "channelSocket.timeout");
        replacements.put("address", "channelSocket.address");            
        replacements.put("bufferSize", "channelSocket.bufferSize");
        replacements.put("tomcatAuthentication", "request.tomcatAuthentication");
        replacements.put("packetSize", "channelSocket.packetSize");
    }

    private void preProcessProperties() {
        Enumeration keys=props.keys();
        Vector v=new Vector();
        
        while( keys.hasMoreElements() ) {
            String key=(String)keys.nextElement();          
            Object newName=replacements.get(key);
            if( newName !=null ) {
                v.addElement(key);
            }
        }
        keys=v.elements();
        while( keys.hasMoreElements() ) {
            String key=(String)keys.nextElement();
            Object propValue=props.getProperty( key );
            String replacement=(String)replacements.get(key);
            props.put(replacement, propValue);
            if( log.isDebugEnabled()) 
                log.debug("Substituting " + key + " " + replacement + " " + 
                    propValue);
        }
    }
    
    private void processProperties() {
        preProcessProperties();
        Enumeration keys=props.keys();

        while( keys.hasMoreElements() ) {
            String name=(String)keys.nextElement();
            String propValue=props.getProperty( name );

            processProperty( name, propValue );
        }
    }

    private void processProperty(String name, String propValue) {
        String type=name;
        String fullName=name;
        String localName="";
        String propName="";
        // ignore
        if( name.startsWith("key.")) return;

        int dot=name.indexOf(".");
        int lastDot=name.lastIndexOf(".");
        if( dot > 0 ) {
            type=name.substring(0, dot );
            if( dot != lastDot ) {
                localName=name.substring( dot + 1, lastDot );
                fullName=type + "." + localName;
            } else {
                fullName=type;
            }
            propName=name.substring( lastDot+1);
        } else {
            return;
        }
        
        if( log.isDebugEnabled() )
            log.debug( "Processing " + type + ":" + localName + ":" + fullName + " " + propName );
        if( "class".equals( type ) || "handler".equals( type ) ) {
            return;
        }
        
        JkHandler comp=getWorkerEnv().getHandler( fullName );
        if( comp==null ) {
            comp=newHandler( type, localName, fullName );
        }
        if( comp==null )
            return;
        
        if( log.isDebugEnabled() ) 
            log.debug("Setting " + propName + " on " + fullName + " " + comp);
        this.setBeanProperty( comp, propName, propValue );
    }

    private JkHandler newHandler( String type, String localName, String fullName )
    {
        JkHandler handler;
        String classN=modules.getProperty(type);
        if( classN == null ) {
            log.error("No class name for " + fullName + " " + type );
            return null;
        }
        try {
            Class channelclass = Class.forName(classN);
            handler=(JkHandler)channelclass.newInstance();
        } catch (Throwable ex) {
            handler=null;
            log.error( "Can't create " + fullName, ex );
            return null;
        }
        if( this.domain != null ) {
            try {
                ObjectName handlerOname = new ObjectName
                    (this.domain + ":" + "type=JkHandler,name=" + fullName);
                Registry.getRegistry(null, null).registerComponent(handler, handlerOname, classN);
            } catch (Exception e) {
                log.error( "Error registering " + fullName, e );
            }

        }
        wEnv.addHandler( fullName, handler );
        return handler;
    }

    private void processModules() {
        Enumeration keys=props.keys();
        int plen=6;
        
        while( keys.hasMoreElements() ) {
            String k=(String)keys.nextElement();
            if( ! k.startsWith( "class." ) )
                continue;

            String name= k.substring( plen );
            String propValue=props.getProperty( k );

            if( log.isDebugEnabled()) log.debug("Register " + name + " " + propValue );
            modules.put( name, propValue );
        }
    }

    private String[] split(String s, String delim ) {
         Vector v=new Vector();
        StringTokenizer st=new StringTokenizer(s, delim );
        while( st.hasMoreTokens() ) {
            v.addElement( st.nextToken());
        }
        String res[]=new String[ v.size() ];
        for( int i=0; i<res.length; i++ ) {
            res[i]=(String)v.elementAt(i);
        }
        return res;
    }

    // guessing home
    private static String CNAME="org/apache/jk/server/JkMain.class";

    private void guessHome() {
        String home= wEnv.getJkHome();
        if( home != null )
            return;
        home=IntrospectionUtils.guessInstall( "jk2.home","jk2.home",
                                              "tomcat-jk2.jar", CNAME );
        if( home != null ) {
            log.info("Guessed home " + home );
            wEnv.setJkHome( home );
        }
    }

    static org.apache.juli.logging.Log log=
        org.apache.juli.logging.LogFactory.getLog( JkMain.class );

    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() {
    }

    public void pause() throws Exception {
        for( int i=0; i<wEnv.getHandlerCount(); i++ ) {
            if( wEnv.getHandler(i) != null ) {
                wEnv.getHandler(i).pause();
            }
        }
    }

    public void resume() throws Exception {
        for( int i=0; i<wEnv.getHandlerCount(); i++ ) {
            if( wEnv.getHandler(i) != null ) {
                wEnv.getHandler(i).resume();
            }
        }
    }


}

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