/**
* 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.hadoop.hbase.util;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URL;
import javax.servlet.http.HttpServlet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.mapred.StatusHttpServer;
import org.mortbay.http.HttpContext;
import org.mortbay.http.SocketListener;
import org.mortbay.http.handler.ResourceHandler;
import org.mortbay.jetty.servlet.WebApplicationContext;
/**
* Create a Jetty embedded server to answer http requests. The primary goal
* is to serve up status information for the server.
* There are three contexts:
* "/stacks/" -> points to stack trace
* "/static/" -> points to common static files (src/webapps/static)
* "/" -> the jsp server code from (src/webapps/<name>)
*/
public class InfoServer {
// Bulk of this class is copied from
// {@link org.apache.hadoop.mapred.StatusHttpServer}. StatusHttpServer
// is not amenable to subclassing. It keeps webAppContext inaccessible
// and will find webapps only in the jar the class StatusHttpServer was
// loaded from.
private static final Log LOG = LogFactory.getLog(InfoServer.class.getName());
private org.mortbay.jetty.Server webServer;
private SocketListener listener;
private boolean findPort;
private WebApplicationContext webAppContext;
/**
* Create a status server on the given port.
* The jsp scripts are taken from src/webapps/<code>name<code>.
* @param name The name of the server
* @param port The port to use on the server
* @param findPort whether the server should start at the given port and
* increment by 1 until it finds a free port.
*/
public InfoServer(String name, String bindAddress, int port, boolean findPort)
throws IOException {
this.webServer = new org.mortbay.jetty.Server();
this.findPort = findPort;
this.listener = new SocketListener();
this.listener.setPort(port);
this.listener.setHost(bindAddress);
this.webServer.addListener(listener);
// Set up the context for "/static/*"
String appDir = getWebAppsPath();
// Set up the context for "/logs/" if "hadoop.log.dir" property is defined.
String logDir = System.getProperty("hadoop.log.dir");
if (logDir != null) {
HttpContext logContext = new HttpContext();
logContext.setContextPath("/logs/*");
logContext.setResourceBase(logDir);
logContext.addHandler(new ResourceHandler());
webServer.addContext(logContext);
}
HttpContext staticContext = new HttpContext();
staticContext.setContextPath("/static/*");
staticContext.setResourceBase(appDir + "/static");
staticContext.addHandler(new ResourceHandler());
this.webServer.addContext(staticContext);
// set up the context for "/" jsp files
String webappDir = null;
try {
webappDir = getWebAppsPath("webapps" + File.separator + name);
} catch (FileNotFoundException e) {
// Retry. Resource may be inside jar on a windows machine.
webappDir = getWebAppsPath("webapps/" + name);
}
this.webAppContext =
this.webServer.addWebApplication("/", webappDir);
addServlet("stacks", "/stacks", StatusHttpServer.StackServlet.class);
}
/**
* Set a value in the webapp context. These values are available to the jsp
* pages as "application.getAttribute(name)".
* @param name The name of the attribute
* @param value The value of the attribute
*/
public void setAttribute(String name, Object value) {
this.webAppContext.setAttribute(name, value);
}
/**
* Add a servlet in the server.
* @param name The name of the servlet (can be passed as null)
* @param pathSpec The path spec for the servlet
* @param servletClass The servlet class
*/
public <T extends HttpServlet> void addServlet(String name, String pathSpec,
Class<T> servletClass) {
WebApplicationContext context = webAppContext;
try {
if (name == null) {
context.addServlet(pathSpec, servletClass.getName());
} else {
context.addServlet(name, pathSpec, servletClass.getName());
}
} catch (ClassNotFoundException ex) {
throw makeRuntimeException("Problem instantiating class", ex);
} catch (InstantiationException ex) {
throw makeRuntimeException("Problem instantiating class", ex);
} catch (IllegalAccessException ex) {
throw makeRuntimeException("Problem instantiating class", ex);
}
}
private static RuntimeException makeRuntimeException(String msg, Throwable cause) {
RuntimeException result = new RuntimeException(msg);
if (cause != null) {
result.initCause(cause);
}
return result;
}
/**
* Get the value in the webapp context.
* @param name The name of the attribute
* @return The value of the attribute
*/
public Object getAttribute(String name) {
return this.webAppContext.getAttribute(name);
}
/**
* Get the pathname to the <code>webapps</code> files.
* @return the pathname as a URL
*/
private static String getWebAppsPath() throws IOException {
return getWebAppsPath("webapps");
}
/**
* Get the pathname to the <code>patch</code> files.
* @param path Path to find.
* @return the pathname as a URL
*/
private static String getWebAppsPath(final String path) throws IOException {
URL url = InfoServer.class.getClassLoader().getResource(path);
if (url == null)
throw new IOException("webapps not found in CLASSPATH");
return url.toString();
}
/**
* Get the port that the server is on
* @return the port
*/
public int getPort() {
return this.listener.getPort();
}
public void setThreads(int min, int max) {
this.listener.setMinThreads(min);
this.listener.setMaxThreads(max);
}
/**
* Start the server. Does not wait for the server to start.
*/
public void start() throws IOException {
try {
while (true) {
try {
this.webServer.start();
break;
} catch (org.mortbay.util.MultiException ex) {
// look for the multi exception containing a bind exception,
// in that case try the next port number.
boolean needNewPort = false;
for(int i=0; i < ex.size(); ++i) {
Exception sub = ex.getException(i);
if (sub instanceof java.net.BindException) {
needNewPort = true;
break;
}
}
if (!findPort || !needNewPort) {
throw ex;
}
this.listener.setPort(listener.getPort() + 1);
}
}
} catch (IOException ie) {
throw ie;
} catch (Exception e) {
IOException ie = new IOException("Problem starting http server");
ie.initCause(e);
throw ie;
}
}
/**
* stop the server
*/
public void stop() throws InterruptedException {
this.webServer.stop();
}
}