bundles/org.eclipse.equinox.servletbridge/src/org/eclipse/equinox/servletbridge/BridgeServlet.java - equinox/rt.equinox.bundles - Git at Google

 /*******************************************************************************
  * Copyright (c) 2005, 2008 Cognos Incorporated, IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     Cognos Incorporated - initial API and implementation
  *     IBM Corporation - bug fixes and enhancements
  *******************************************************************************/
 package org.eclipse.equinox.servletbridge;

 import java.io.IOException;
 import javax.servlet.ServletException;
 import javax.servlet.http.*;

 /**
  * The BridgeServlet provides a means to bridge the servlet and OSGi
  * runtimes. This class has 3 main responsibilities:
  * 1) Control the lifecycle of the associated FrameworkLauncher in line with its own lifecycle
  * 2) Provide a servlet "hook" that allows all servlet requests to be delegated to the registered servlet
  * 3) Provide means to manually control the framework lifecycle
  */
 public class BridgeServlet extends HttpServlet {

 	static final String INCLUDE_REQUEST_URI_ATTRIBUTE = "javax.servlet.include.request_uri"; //$NON-NLS-1$
 	static final String INCLUDE_SERVLET_PATH_ATTRIBUTE = "javax.servlet.include.servlet_path"; //$NON-NLS-1$
 	static final String INCLUDE_PATH_INFO_ATTRIBUTE = "javax.servlet.include.path_info"; //$NON-NLS-1$

 	private static final long serialVersionUID = 2825667412474494674L;
 	private static BridgeServlet instance;
 	private HttpServlet delegate;
 	private FrameworkLauncher framework;
 	private int delegateReferenceCount;
 	private boolean enableFrameworkControls;

 	/**
 	 * init() is called by the Servlet Container and used to instantiate the frameworkLauncher which MUST be an instance of FrameworkLauncher.
 	 * After instantiating the framework init, deploy, and start are called.
 	 */
 	public void init() throws ServletException {
 		super.init();

 		String enableFrameworkControlsParameter = getServletConfig().getInitParameter("enableFrameworkControls"); //$NON-NLS-1$
 		enableFrameworkControls = (enableFrameworkControlsParameter != null && enableFrameworkControlsParameter.equals("true")); //$NON-NLS-1$

 		String frameworkLauncherClassParameter = getServletConfig().getInitParameter("frameworkLauncherClass"); //$NON-NLS-1$
 		if (frameworkLauncherClassParameter != null) {
 			try {
 				Class frameworkLauncherClass = this.getClass().getClassLoader().loadClass(frameworkLauncherClassParameter);
 				framework = (FrameworkLauncher) frameworkLauncherClass.newInstance();
 			} catch (Exception e) {
 				throw new ServletException(e);
 			}
 		} else {
 			framework = new FrameworkLauncher();
 		}

 		boolean frameworkStarted = false;
 		setInstance(this);
 		try {
 			framework.init(getServletConfig());
 			framework.deploy();
 			framework.start();
 			frameworkStarted = true;
 		} finally {
 			if (!frameworkStarted)
 				setInstance(null);
 		}
 	}

 	/**
 	 * destroy() is called by the Servlet Container and used to first stop and then destroy the framework.
 	 */
 	public void destroy() {
 		framework.stop();
 		framework.destroy();
 		setInstance(null);
 		super.destroy();
 	}

 	/**
 	 * service is called by the Servlet Container and will first determine if the request is a
 	 * framework control and will otherwise try to delegate to the registered servlet delegate
 	 *
 	 */
 	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
 		String pathInfo = req.getPathInfo();
 		// Check if this is being handled by an extension mapping
 		if (pathInfo == null && isExtensionMapping(req.getServletPath()))
 			req = new ExtensionMappingRequest(req);

 		if (req.getAttribute(INCLUDE_REQUEST_URI_ATTRIBUTE) == null) {
 			if (enableFrameworkControls) {
 				if (pathInfo != null && pathInfo.startsWith("/sp_")) { //$NON-NLS-1$
 					if (serviceFrameworkControls(req, resp)) {
 						return;
 					}
 				}
 			}
 		} else {
 			String includePathInfo = (String) req.getAttribute(INCLUDE_PATH_INFO_ATTRIBUTE);
 			// Check if this is being handled by an extension mapping
 			if (includePathInfo == null || includePathInfo.length() == 0) {
 				String servletPath = (String) req.getAttribute(INCLUDE_SERVLET_PATH_ATTRIBUTE);
 				if (isExtensionMapping(servletPath))
 					req = new IncludedExtensionMappingRequest(req);
 			}
 		}

 		ClassLoader original = Thread.currentThread().getContextClassLoader();
 		HttpServlet servletReference = acquireDelegateReference();
 		if (servletReference == null) {
 			resp.sendError(HttpServletResponse.SC_NOT_FOUND, "BridgeServlet: " + req.getRequestURI()); //$NON-NLS-1$
 			return;
 		}
 		try {
 			Thread.currentThread().setContextClassLoader(framework.getFrameworkContextClassLoader());
 			servletReference.service(req, resp);
 		} finally {
 			releaseDelegateReference();
 			Thread.currentThread().setContextClassLoader(original);
 		}
 	}

 	private boolean isExtensionMapping(String servletPath) {
 		if (servletPath == null)
 			return false;

 		String lastSegment = servletPath;
 		int lastSlash = servletPath.lastIndexOf('/');
 		if (lastSlash != -1)
 			lastSegment = servletPath.substring(lastSlash + 1);

 		return lastSegment.indexOf('.') != -1;
 	}

 	/**
 	 * serviceFrameworkControls currently supports the following commands (identified by the request's pathinfo)
 	 * sp_deploy - Copies the contents of /platform to the install area
 	 * sp_undeploy - Removes the copy of Eclipse from the install area
 	 * sp_redeploy - Resets the platform (e.g. stops, undeploys, deploys, starts)
 	 * sp_start - Starts a deployed platform
 	 * sp_stop - Stops the platform
 	 */
 	private boolean serviceFrameworkControls(HttpServletRequest req, HttpServletResponse resp) throws IOException {
 		String pathInfo = req.getPathInfo();
 		if (pathInfo.equals("/sp_start")) { //$NON-NLS-1$
 			framework.start();
 			resp.getWriter().write("Platform Started"); //$NON-NLS-1$
 			return true;
 		} else if (pathInfo.equals("/sp_stop")) { //$NON-NLS-1$
 			framework.stop();
 			resp.getWriter().write("Platform Stopped"); //$NON-NLS-1$
 			return true;
 		} else if (pathInfo.equals("/sp_deploy")) { //$NON-NLS-1$
 			framework.deploy();
 			resp.getWriter().write("Platform Deployed"); //$NON-NLS-1$
 			return true;
 		} else if (pathInfo.equals("/sp_undeploy")) { //$NON-NLS-1$
 			framework.undeploy();
 			resp.getWriter().write("Platform Undeployed"); //$NON-NLS-1$
 			return true;
 		} else if (pathInfo.equals("/sp_reset")) { //$NON-NLS-1$
 			framework.stop();
 			framework.start();
 			resp.getWriter().write("Platform Reset"); //$NON-NLS-1$
 			return true;
 		} else if (pathInfo.equals("/sp_redeploy")) { //$NON-NLS-1$
 			framework.stop();
 			framework.undeploy();
 			framework.deploy();
 			framework.start();
 			resp.getWriter().write("Platform Redeployed"); //$NON-NLS-1$
 			return true;
 		} else if (pathInfo.equals("/sp_test")) { //$NON-NLS-1$
 			if (delegate == null)
 				resp.getWriter().write("Servlet delegate not registered."); //$NON-NLS-1$
 			else
 				resp.getWriter().write("Servlet delegate registered - " + delegate.getClass().getName()); //$NON-NLS-1$
 			return true;
 		}
 		return false;
 	}

 	private static synchronized void setInstance(BridgeServlet servlet) {
 		if ((instance != null) && (servlet != null))
 			throw new IllegalStateException("instance already set"); //$NON-NLS-1$
 		instance = servlet;
 	}

 	private synchronized void releaseDelegateReference() {
 		--delegateReferenceCount;
 		notifyAll();
 	}

 	private synchronized HttpServlet acquireDelegateReference() {
 		if (delegate != null)
 			++delegateReferenceCount;
 		return delegate;
 	}

 	/**
 	 * registerServletDelegate is the hook method called from inside the OSGi runtime to register
 	 * a servlet for which all future servlet calls will be delegated. If not null and no delegate
 	 * is currently registered, init(ServletConfig) will be called on the servletDelegate before
 	 * returning.
 	 * @param servletDelegate - the servlet to register for delegation
 	 */
 	public static synchronized void registerServletDelegate(HttpServlet servletDelegate) {
 		if (instance == null) {
 			// shutdown already
 			return;
 		}

 		if (servletDelegate == null)
 			throw new NullPointerException("cannot register a null servlet delegate"); //$NON-NLS-1$

 		synchronized (instance) {
 			if (instance.delegate != null)
 				throw new IllegalStateException("A Servlet Proxy is already registered"); //$NON-NLS-1$

 			try {
 				servletDelegate.init(instance.getServletConfig());
 			} catch (ServletException e) {
 				instance.getServletContext().log("Error initializing servlet delegate", e); //$NON-NLS-1$
 				return;
 			}
 			instance.delegate = servletDelegate;
 		}
 	}

 	/**
 	 * unregisterServletDelegate is the hook method called from inside the OSGi runtime to unregister a delegate.
 	 * If the servletDelegate matches the current registered delegate destroy() is called on the servletDelegate.
 	 * destroy() will not be called until the delegate is finished servicing any previous requests.
 	 * @param servletDelegate - the servlet to unregister
 	 */
 	public static synchronized void unregisterServletDelegate(HttpServlet servletDelegate) {
 		if (instance == null) {
 			// shutdown already
 			return;
 		}

 		synchronized (instance) {
 			if (instance.delegate == null)
 				throw new IllegalStateException("No servlet delegate is registered"); //$NON-NLS-1$

 			if (instance.delegate != servletDelegate)
 				throw new IllegalStateException("Servlet delegate does not match registered servlet delegate"); //$NON-NLS-1$

 			HttpServlet oldProxy = instance.delegate;
 			instance.delegate = null;
 			while (instance.delegateReferenceCount != 0) {
 				try {
 					instance.wait();
 				} catch (InterruptedException e) {
 					// keep waiting for all requests to finish
 				}
 			}
 			oldProxy.destroy();
 		}
 	}

 	static class ExtensionMappingRequest extends HttpServletRequestWrapper {

 		public ExtensionMappingRequest(HttpServletRequest req) {
 			super(req);
 		}

 		public String getPathInfo() {
 			return super.getServletPath();
 		}

 		public String getServletPath() {
 			return ""; //$NON-NLS-1$
 		}
 	}

 	static class IncludedExtensionMappingRequest extends HttpServletRequestWrapper {

 		public IncludedExtensionMappingRequest(HttpServletRequest req) {
 			super(req);
 		}

 		public Object getAttribute(String attributeName) {
 			if (attributeName.equals(INCLUDE_SERVLET_PATH_ATTRIBUTE)) {
 				return ""; //$NON-NLS-1$
 			} else if (attributeName.equals(INCLUDE_PATH_INFO_ATTRIBUTE)) {
 				String servletPath = (String) super.getAttribute(INCLUDE_SERVLET_PATH_ATTRIBUTE);
 				return servletPath;
 			}
 			return super.getAttribute(attributeName);
 		}
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2005, 2008 Cognos Incorporated, IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Cognos Incorporated - initial API and implementation
	* IBM Corporation - bug fixes and enhancements
	*******************************************************************************/
	package org.eclipse.equinox.servletbridge;

	import java.io.IOException;
	import javax.servlet.ServletException;
	import javax.servlet.http.*;

	/**
	* The BridgeServlet provides a means to bridge the servlet and OSGi
	* runtimes. This class has 3 main responsibilities:
	* 1) Control the lifecycle of the associated FrameworkLauncher in line with its own lifecycle
	* 2) Provide a servlet "hook" that allows all servlet requests to be delegated to the registered servlet
	* 3) Provide means to manually control the framework lifecycle
	*/
	public class BridgeServlet extends HttpServlet {

	static final String INCLUDE_REQUEST_URI_ATTRIBUTE = "javax.servlet.include.request_uri"; //$NON-NLS-1$
	static final String INCLUDE_SERVLET_PATH_ATTRIBUTE = "javax.servlet.include.servlet_path"; //$NON-NLS-1$
	static final String INCLUDE_PATH_INFO_ATTRIBUTE = "javax.servlet.include.path_info"; //$NON-NLS-1$

	private static final long serialVersionUID = 2825667412474494674L;
	private static BridgeServlet instance;
	private HttpServlet delegate;
	private FrameworkLauncher framework;
	private int delegateReferenceCount;
	private boolean enableFrameworkControls;

	/**
	* init() is called by the Servlet Container and used to instantiate the frameworkLauncher which MUST be an instance of FrameworkLauncher.
	* After instantiating the framework init, deploy, and start are called.
	*/
	public void init() throws ServletException {
	super.init();

	String enableFrameworkControlsParameter = getServletConfig().getInitParameter("enableFrameworkControls"); //$NON-NLS-1$
	enableFrameworkControls = (enableFrameworkControlsParameter != null && enableFrameworkControlsParameter.equals("true")); //$NON-NLS-1$

	String frameworkLauncherClassParameter = getServletConfig().getInitParameter("frameworkLauncherClass"); //$NON-NLS-1$
	if (frameworkLauncherClassParameter != null) {
	try {
	Class frameworkLauncherClass = this.getClass().getClassLoader().loadClass(frameworkLauncherClassParameter);
	framework = (FrameworkLauncher) frameworkLauncherClass.newInstance();
	} catch (Exception e) {
	throw new ServletException(e);
	}
	} else {
	framework = new FrameworkLauncher();
	}

	boolean frameworkStarted = false;
	setInstance(this);
	try {
	framework.init(getServletConfig());
	framework.deploy();
	framework.start();
	frameworkStarted = true;
	} finally {
	if (!frameworkStarted)
	setInstance(null);
	}
	}

	/**
	* destroy() is called by the Servlet Container and used to first stop and then destroy the framework.
	*/
	public void destroy() {
	framework.stop();
	framework.destroy();
	setInstance(null);
	super.destroy();
	}

	/**
	* service is called by the Servlet Container and will first determine if the request is a
	* framework control and will otherwise try to delegate to the registered servlet delegate
	*
	*/
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
	String pathInfo = req.getPathInfo();
	// Check if this is being handled by an extension mapping
	if (pathInfo == null && isExtensionMapping(req.getServletPath()))
	req = new ExtensionMappingRequest(req);

	if (req.getAttribute(INCLUDE_REQUEST_URI_ATTRIBUTE) == null) {
	if (enableFrameworkControls) {
	if (pathInfo != null && pathInfo.startsWith("/sp_")) { //$NON-NLS-1$
	if (serviceFrameworkControls(req, resp)) {
	return;
	}
	}
	}
	} else {
	String includePathInfo = (String) req.getAttribute(INCLUDE_PATH_INFO_ATTRIBUTE);
	// Check if this is being handled by an extension mapping
	if (includePathInfo == null \|\| includePathInfo.length() == 0) {
	String servletPath = (String) req.getAttribute(INCLUDE_SERVLET_PATH_ATTRIBUTE);
	if (isExtensionMapping(servletPath))
	req = new IncludedExtensionMappingRequest(req);
	}
	}

	ClassLoader original = Thread.currentThread().getContextClassLoader();
	HttpServlet servletReference = acquireDelegateReference();
	if (servletReference == null) {
	resp.sendError(HttpServletResponse.SC_NOT_FOUND, "BridgeServlet: " + req.getRequestURI()); //$NON-NLS-1$
	return;
	}
	try {
	Thread.currentThread().setContextClassLoader(framework.getFrameworkContextClassLoader());
	servletReference.service(req, resp);
	} finally {
	releaseDelegateReference();
	Thread.currentThread().setContextClassLoader(original);
	}
	}

	private boolean isExtensionMapping(String servletPath) {
	if (servletPath == null)
	return false;

	String lastSegment = servletPath;
	int lastSlash = servletPath.lastIndexOf('/');
	if (lastSlash != -1)
	lastSegment = servletPath.substring(lastSlash + 1);

	return lastSegment.indexOf('.') != -1;
	}

	/**
	* serviceFrameworkControls currently supports the following commands (identified by the request's pathinfo)
	* sp_deploy - Copies the contents of /platform to the install area
	* sp_undeploy - Removes the copy of Eclipse from the install area
	* sp_redeploy - Resets the platform (e.g. stops, undeploys, deploys, starts)
	* sp_start - Starts a deployed platform
	* sp_stop - Stops the platform
	*/
	private boolean serviceFrameworkControls(HttpServletRequest req, HttpServletResponse resp) throws IOException {
	String pathInfo = req.getPathInfo();
	if (pathInfo.equals("/sp_start")) { //$NON-NLS-1$
	framework.start();
	resp.getWriter().write("Platform Started"); //$NON-NLS-1$
	return true;
	} else if (pathInfo.equals("/sp_stop")) { //$NON-NLS-1$
	framework.stop();
	resp.getWriter().write("Platform Stopped"); //$NON-NLS-1$
	return true;
	} else if (pathInfo.equals("/sp_deploy")) { //$NON-NLS-1$
	framework.deploy();
	resp.getWriter().write("Platform Deployed"); //$NON-NLS-1$
	return true;
	} else if (pathInfo.equals("/sp_undeploy")) { //$NON-NLS-1$
	framework.undeploy();
	resp.getWriter().write("Platform Undeployed"); //$NON-NLS-1$
	return true;
	} else if (pathInfo.equals("/sp_reset")) { //$NON-NLS-1$
	framework.stop();
	framework.start();
	resp.getWriter().write("Platform Reset"); //$NON-NLS-1$
	return true;
	} else if (pathInfo.equals("/sp_redeploy")) { //$NON-NLS-1$
	framework.stop();
	framework.undeploy();
	framework.deploy();
	framework.start();
	resp.getWriter().write("Platform Redeployed"); //$NON-NLS-1$
	return true;
	} else if (pathInfo.equals("/sp_test")) { //$NON-NLS-1$
	if (delegate == null)
	resp.getWriter().write("Servlet delegate not registered."); //$NON-NLS-1$
	else
	resp.getWriter().write("Servlet delegate registered - " + delegate.getClass().getName()); //$NON-NLS-1$
	return true;
	}
	return false;
	}

	private static synchronized void setInstance(BridgeServlet servlet) {
	if ((instance != null) && (servlet != null))
	throw new IllegalStateException("instance already set"); //$NON-NLS-1$
	instance = servlet;
	}

	private synchronized void releaseDelegateReference() {
	--delegateReferenceCount;
	notifyAll();
	}

	private synchronized HttpServlet acquireDelegateReference() {
	if (delegate != null)
	++delegateReferenceCount;
	return delegate;
	}

	/**
	* registerServletDelegate is the hook method called from inside the OSGi runtime to register
	* a servlet for which all future servlet calls will be delegated. If not null and no delegate
	* is currently registered, init(ServletConfig) will be called on the servletDelegate before
	* returning.
	* @param servletDelegate - the servlet to register for delegation
	*/
	public static synchronized void registerServletDelegate(HttpServlet servletDelegate) {
	if (instance == null) {
	// shutdown already
	return;
	}

	if (servletDelegate == null)
	throw new NullPointerException("cannot register a null servlet delegate"); //$NON-NLS-1$

	synchronized (instance) {
	if (instance.delegate != null)
	throw new IllegalStateException("A Servlet Proxy is already registered"); //$NON-NLS-1$

	try {
	servletDelegate.init(instance.getServletConfig());
	} catch (ServletException e) {
	instance.getServletContext().log("Error initializing servlet delegate", e); //$NON-NLS-1$
	return;
	}
	instance.delegate = servletDelegate;
	}
	}

	/**
	* unregisterServletDelegate is the hook method called from inside the OSGi runtime to unregister a delegate.
	* If the servletDelegate matches the current registered delegate destroy() is called on the servletDelegate.
	* destroy() will not be called until the delegate is finished servicing any previous requests.
	* @param servletDelegate - the servlet to unregister
	*/
	public static synchronized void unregisterServletDelegate(HttpServlet servletDelegate) {
	if (instance == null) {
	// shutdown already
	return;
	}

	synchronized (instance) {
	if (instance.delegate == null)
	throw new IllegalStateException("No servlet delegate is registered"); //$NON-NLS-1$

	if (instance.delegate != servletDelegate)
	throw new IllegalStateException("Servlet delegate does not match registered servlet delegate"); //$NON-NLS-1$

	HttpServlet oldProxy = instance.delegate;
	instance.delegate = null;
	while (instance.delegateReferenceCount != 0) {
	try {
	instance.wait();
	} catch (InterruptedException e) {
	// keep waiting for all requests to finish
	}
	}
	oldProxy.destroy();
	}
	}

	static class ExtensionMappingRequest extends HttpServletRequestWrapper {

	public ExtensionMappingRequest(HttpServletRequest req) {
	super(req);
	}

	public String getPathInfo() {
	return super.getServletPath();
	}

	public String getServletPath() {
	return ""; //$NON-NLS-1$
	}
	}

	static class IncludedExtensionMappingRequest extends HttpServletRequestWrapper {

	public IncludedExtensionMappingRequest(HttpServletRequest req) {
	super(req);
	}

	public Object getAttribute(String attributeName) {
	if (attributeName.equals(INCLUDE_SERVLET_PATH_ATTRIBUTE)) {
	return ""; //$NON-NLS-1$
	} else if (attributeName.equals(INCLUDE_PATH_INFO_ATTRIBUTE)) {
	String servletPath = (String) super.getAttribute(INCLUDE_SERVLET_PATH_ATTRIBUTE);
	return servletPath;
	}
	return super.getAttribute(attributeName);
	}
	}

	}