Tomcat example source code file (ValveBase.java)

This example Tomcat source code file (ValveBase.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

container, containerbase, context, host, host, io, ioexception, management, objectname, objectname, response, servlet, servletexception, string, string, valve, valve

The Tomcat ValveBase.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.valves;


import java.io.IOException;

import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.servlet.ServletException;

import org.apache.catalina.CometEvent;
import org.apache.catalina.Contained;
import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Engine;
import org.apache.catalina.Host;
import org.apache.catalina.Pipeline;
import org.apache.catalina.Valve;
import org.apache.catalina.Wrapper;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.core.ContainerBase;
import org.apache.catalina.util.StringManager;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;


/**
 * Convenience base class for implementations of the <b>Valve interface.
 * A subclass <strong>MUST implement an invoke()
 * method to provide the required functionality, and <strong>MAY
 * implement the <code>Lifecycle interface to provide configuration
 * management and lifecycle support.
 *
 * @author Craig R. McClanahan
 * @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */

public abstract class ValveBase
    implements Contained, Valve, MBeanRegistration {
    private static Log log = LogFactory.getLog(ValveBase.class);

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


    /**
     * The Container whose pipeline this Valve is a component of.
     */
    protected Container container = null;


    /**
     * Container log
     */
    protected Log containerLog = null;


    /**
     * Descriptive information about this Valve implementation.  This value
     * should be overridden by subclasses.
     */
    protected static String info =
        "org.apache.catalina.core.ValveBase/1.0";


    /**
     * The next Valve in the pipeline this Valve is a component of.
     */
    protected Valve next = null;


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


    //-------------------------------------------------------------- Properties


    /**
     * Return the Container with which this Valve is associated, if any.
     */
    public Container getContainer() {

        return (container);

    }


    /**
     * Set the Container with which this Valve is associated, if any.
     *
     * @param container The new associated container
     */
    public void setContainer(Container container) {

        this.container = container;

    }


    /**
     * Return descriptive information about this Valve implementation.
     */
    public String getInfo() {

        return (info);

    }


    /**
     * Return the next Valve in this pipeline, or <code>null if this
     * is the last Valve in the pipeline.
     */
    public Valve getNext() {

        return (next);

    }


    /**
     * Set the Valve that follows this one in the pipeline it is part of.
     *
     * @param valve The new next valve
     */
    public void setNext(Valve valve) {

        this.next = valve;

    }


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


    /**
     * Execute a periodic task, such as reloading, etc. This method will be
     * invoked inside the classloading context of this container. Unexpected
     * throwables will be caught and logged.
     */
    public void backgroundProcess() {
    }


    /**
     * The implementation-specific logic represented by this Valve.  See the
     * Valve description for the normal design patterns for this method.
     * <p>
     * This method <strong>MUST be provided by a subclass.
     *
     * @param request The servlet request to be processed
     * @param response The servlet response to be created
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public abstract void invoke(Request request, Response response)
        throws IOException, ServletException;


    /**
     * Process a Comet event. This method will rarely need to be provided by
     * a subclass, unless it needs to reassociate a particular object with 
     * the thread that is processing the request.
     *
     * @param request The servlet request to be processed
     * @param response The servlet response to be created
     *
     * @exception IOException if an input/output error occurs, or is thrown
     *  by a subsequently invoked Valve, Filter, or Servlet
     * @exception ServletException if a servlet error occurs, or is thrown
     *  by a subsequently invoked Valve, Filter, or Servlet
     */
    public void event(Request request, Response response, CometEvent event)
        throws IOException, ServletException {
        // Perform the request
        getNext().event(request, response, event);
    }


    /**
     * Return a String rendering of this object.
     */
    public String toString() {
        StringBuffer sb = new StringBuffer(this.getClass().getName());
        sb.append("[");
        if (container != null)
            sb.append(container.getName());
        sb.append("]");
        return (sb.toString());
    }


    // -------------------- JMX and Registration  --------------------
    protected String domain;
    protected ObjectName oname;
    protected MBeanServer mserver;
    protected ObjectName controller;

    public ObjectName getObjectName() {
        return oname;
    }

    public void setObjectName(ObjectName oname) {
        this.oname = 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 ObjectName getController() {
        return controller;
    }

    public void setController(ObjectName controller) {
        this.controller = controller;
    }

    /** From the name, extract the parent object name
     *
     * @param valveName The valve name
     * @return ObjectName The parent name
     */
    public ObjectName getParentName( ObjectName valveName ) {

        return null;
    }

    public ObjectName createObjectName(String domain, ObjectName parent)
            throws MalformedObjectNameException
    {
        Container container=this.getContainer();
        if( container == null || ! (container instanceof ContainerBase) )
            return null;
        this.containerLog = container.getLogger();
        ContainerBase containerBase=(ContainerBase)container;
        Pipeline pipe=containerBase.getPipeline();
        Valve valves[]=pipe.getValves();

        /* Compute the "parent name" part */
        String parentName="";
        if (container instanceof Engine) {
        } else if (container instanceof Host) {
            parentName=",host=" +container.getName();
        } else if (container instanceof Context) {
                    String path = ((Context)container).getPath();
                    if (path.length() < 1) {
                        path = "/";
                    }
                    Host host = (Host) container.getParent();
                    parentName=",path=" + path + ",host=" +
                            host.getName();
        } else if (container instanceof Wrapper) {
            Context ctx = (Context) container.getParent();
            String path = ctx.getPath();
            if (path.length() < 1) {
                path = "/";
            }
            Host host = (Host) ctx.getParent();
            parentName=",servlet=" + container.getName() +
                    ",path=" + path + ",host=" + host.getName();
        }
        log.debug("valve parent=" + parentName + " " + parent);

        String className=this.getClass().getName();
        int period = className.lastIndexOf('.');
        if (period >= 0)
            className = className.substring(period + 1);

        int seq=0;
        for( int i=0; i<valves.length; i++ ) {
            // Find other valves with the same name
            if (valves[i] == this) {
                break;
            }
            if( valves[i]!=null &&
                    valves[i].getClass() == this.getClass() ) {
                log.debug("Duplicate " + valves[i] + " " + this + " " + container);
                seq++;
            }
        }
        String ext="";
        if( seq > 0 ) {
            ext=",seq=" + seq;
        }

        ObjectName objectName = 
            new ObjectName( domain + ":type=Valve,name=" + className + ext + parentName);
        log.debug("valve objectname = "+objectName);
        return objectName;
    }

    // -------------------- JMX data  --------------------

    public ObjectName getContainerName() {
        if( container== null) return null;
        return ((ContainerBase)container).getJmxName();
    }
}