org.apache.jcs.auxiliary.remote.server.RemoteCacheStartupServlet.java Source code

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Here is the source code for org.apache.jcs.auxiliary.remote.server.RemoteCacheStartupServlet.java

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package org.apache.jcs.auxiliary.remote.server;

/*
 * 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.
 */

import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.util.Properties;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.jcs.engine.control.CompositeCacheManager;
import org.apache.jcs.utils.props.PropertyLoader;

/**
 * This servlet can be used to startup the JCS remote cache. It is easy to
 * deploy the remote server in a tomcat base. This give you an easy way to
 * monitor its activity.
 * <p>
 *
 * <code>
 *  <servlet>
    <servlet-name>JCSRemoteCacheStartupServlet</servlet-name>
    <servlet-class>
         org.apache.jcs.auxiliary.remote.server.RemoteCacheStartupServlet
    </servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
    
    
<servlet-mapping>
    <servlet-name>JCSRemoteCacheStartupServlet</servlet-name>
    <url-pattern>/jcs</url-pattern>
</servlet-mapping>
 * </code>
 *
 *
 * @author Aaron Smuts
 *
 */
public class RemoteCacheStartupServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    private final static Log log = LogFactory.getLog(RemoteCacheStartupServlet.class);

    private static final int DEFAULT_REGISTRY_PORT = 1101;

    private static final String DEFAULT_PROPS_FILE_NAME = "cache.ccf";

    /**
     * Starts the registry and then tries to bind to it.
     * <p>
     * Gets the port from a props file. Uses the local host name for the rgistry
     * host. Tries to start the registry, ignoreing failure. Starts the server.
     */
    public void init() throws ServletException {
        super.init();
        // TODO load from props file or get as init param or get from jndi, or
        // all three
        int registryPort = DEFAULT_REGISTRY_PORT;

        try {
            Properties props = PropertyLoader.loadProperties(DEFAULT_PROPS_FILE_NAME);
            if (props != null) {
                String portS = props.getProperty("registry.port", String.valueOf(DEFAULT_REGISTRY_PORT));

                try {
                    registryPort = Integer.parseInt(portS);
                } catch (NumberFormatException e) {
                    log.error("Problem converting port to an int.", e);
                }
            }
        } catch (Exception e) {
            log.error("Problem loading props.", e);
        } catch (Throwable t) {
            log.error("Problem loading props.", t);
        }

        // we will always use the local machine for the registry
        String registryHost;
        try {
            registryHost = InetAddress.getLocalHost().getHostAddress();

            if (log.isDebugEnabled()) {
                log.debug("registryHost = [" + registryHost + "]");
            }

            if ("localhost".equals(registryHost) || "127.0.0.1".equals(registryHost)) {
                log.warn("The local address [" + registryHost
                        + "] is INVALID.  Other machines must be able to use the address to reach this server.");
            }

            try {
                LocateRegistry.createRegistry(registryPort);
            } catch (RemoteException e) {
                log.error("Problem creating registry.  It may already be started. " + e.getMessage());
            } catch (Throwable t) {
                log.error("Problem creating registry.", t);
            }

            try {
                RemoteCacheServerFactory.startup(registryHost, registryPort, "/" + DEFAULT_PROPS_FILE_NAME);
            } catch (IOException e) {
                log.error("Problem starting remote cache server.", e);
            }

            catch (Throwable t) {
                log.error("Problem starting remote cache server.", t);
            }
        } catch (UnknownHostException e) {
            log.error("Could not get local address to use for the registry!", e);
        }
    }

    /**
     * It just dumps the stats.
     */
    protected void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String stats = CompositeCacheManager.getInstance().getStats();
        if (log.isInfoEnabled()) {
            log.info(stats);
        }

        try {
            OutputStream os = response.getOutputStream();
            os.write(stats.getBytes());
            os.close();
        } catch (IOException e) {
            log.error("Problem writing response.", e);
        }
    }

    /*
     * (non-Javadoc)
     *
     * @see javax.servlet.Servlet#destroy()
     */
    public void destroy() {
        super.destroy();

        log.info("Shutting down remote cache ");

        CompositeCacheManager.getInstance().shutDown();
    }
}