src/main/java/org/apache/sling/extensions/gwt/user/server/rpc/SlingRemoteServiceServlet.java - sling-old-svn-mirror - Git at Google

 /*
  * 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.sling.extensions.gwt.user.server.rpc;

 import com.google.gwt.user.client.rpc.SerializationException;
 import com.google.gwt.user.server.rpc.RemoteServiceServlet;
 import com.google.gwt.user.server.rpc.SerializationPolicy;
 import com.google.gwt.user.server.rpc.SerializationPolicyLoader;
 import org.osgi.framework.Bundle;

 import javax.servlet.http.HttpServletRequest;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.text.ParseException;

 /**
  * Extending google's remote service servlet to enable resolving of resources through
  * a bundle (for policy file loading).
  * <p/>
  * This class is for version 2.0.3 of the GWT gwt-servlet.jar edition and it is highly recommended to compile
  * client apps with the corresponding 2.0.3 GWT gwt-user.jar only!
  * <p/>
  * GWT service servlets that are used in sling are required to extend the <code>SlingRemoteServiceServlet</code>
  * instead of google's own <code>RemoteServiceServlet</code>.
  * </code>
  */
 public class SlingRemoteServiceServlet extends RemoteServiceServlet {

     /**
      * The <code>org.osgi.framework.Bundle</code> to load resources from.
      */
     private Bundle bundle;

     /**
      * The <code>ClassLoader</code> to use when GWT reflects on RPC classes.
      */
     private ClassLoader classLoader;

     /**
      * Process a call originating from the given request. Uses the
      * {@link com.google.gwt.user.server.rpc.RPC#invokeAndEncodeResponse(Object, java.lang.reflect.Method, Object[])}
      * method to do the actual work.
      * <p>
      * Subclasses may optionally override this method to handle the payload in any
      * way they desire (by routing the request to a framework component, for
      * instance). The {@link javax.servlet.http.HttpServletRequest} and {@link javax.servlet.http.HttpServletResponse}
      * can be accessed via the {@link #getThreadLocalRequest()} and
      * {@link #getThreadLocalResponse()} methods.
      * </p>
      * This is public so that it can be unit tested easily without HTTP.
      * <p/>
      * In order to properly operate within Sling/OSGi, the classloader used by GWT has to be rerouted from
      * <code>Thread.currentThread().getContextClassLoader()</code> to the classloader provided by the bundle.
      *
      * @param payload the UTF-8 request payload
      * @return a string which encodes either the method's return, a checked
      *         exception thrown by the method, or an
      *         {@link com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException}
      * @throws com.google.gwt.user.client.rpc.SerializationException
      *                          if we cannot serialize the response
      * @throws com.google.gwt.user.server.rpc.UnexpectedException
      *                          if the invocation throws a checked exception
      *                          that is not declared in the service method's signature
      * @throws RuntimeException if the service method throws an unchecked
      *                          exception (the exception will be the one thrown by the service)
      */
     @Override
     public String processCall(String payload) throws SerializationException {
         String result;
         if (classLoader != null) {
             final ClassLoader old = Thread.currentThread().getContextClassLoader();
             Thread.currentThread().setContextClassLoader(classLoader);
             result = super.processCall(payload);
             Thread.currentThread().setContextClassLoader(old);
         } else {
             result = super.processCall(payload);
         }
         return result;
     }

     /**
      * Gets the {@link com.google.gwt.user.server.rpc.SerializationPolicy} for given module base URL and strong
      * name if there is one.
      * <p/>
      * Override this method to provide a {@link com.google.gwt.user.server.rpc.SerializationPolicy} using an
      * alternative approach.
      * <p/>
      * This method has been overriden, so that the serialization policy can be properly loaded as a bundle entry,
      * as Sling does not support <code>ServletContext.getResourceAsStream()</code>.
      *
      * @param request       the HTTP request being serviced
      * @param moduleBaseURL as specified in the incoming payload
      * @param strongName    a strong name that uniquely identifies a serialization
      *                      policy file
      * @return a {@link com.google.gwt.user.server.rpc.SerializationPolicy} for the given module base URL and
      *         strong name, or <code>null</code> if there is none
      */
     @Override
     protected SerializationPolicy doGetSerializationPolicy(HttpServletRequest request, String moduleBaseURL, String strongName) {

         // The request can tell you the path of the web app relative to the
         // container root.
         String contextPath = request.getContextPath();

         String modulePath = null;
         if (moduleBaseURL != null) {
             try {
                 modulePath = new URL(moduleBaseURL).getPath();
             } catch (MalformedURLException ex) {
                 // log the information, we will default
                 getServletContext().log("Malformed moduleBaseURL: " + moduleBaseURL, ex);
             }
         }

         SerializationPolicy serializationPolicy = null;

         /*
         * Check that the module path must be in the same web app as the servlet
         * itself. If you need to implement a scheme different than this, override
         * this method.
         */
         if (modulePath == null || !modulePath.startsWith(contextPath)) {
             String message = "ERROR: The module path requested, "
                     + modulePath
                     + ", is not in the same web application as this servlet, "
                     + contextPath
                     + ".  Your module may not be properly configured or your client and server code maybe out of date.";
             getServletContext().log(message);
         } else {
             // Strip off the context path from the module base URL. It should be a
             // strict prefix.
             String contextRelativePath = modulePath.substring(contextPath.length());

             String serializationPolicyFilePath = SerializationPolicyLoader.getSerializationPolicyFileName(contextRelativePath
                     + strongName);

             // Open the RPC resource file read its contents.
             InputStream is = null;
             // if the bundle was set by the extending class, load the resource from it instead of the servlet context
             if (bundle != null) {
                 try {
                     is = bundle.getResource(serializationPolicyFilePath).openStream();
                 } catch (IOException e) {
                     //ignore
                 }
             } else {
                 is = getServletContext().getResourceAsStream(
                         serializationPolicyFilePath);
             }
             try {
                 if (is != null) {
                     try {
                         serializationPolicy = SerializationPolicyLoader.loadFromStream(is, null);
                     } catch (ParseException e) {
                         getServletContext().log(
                                 "ERROR: Failed to parse the policy file '"
                                         + serializationPolicyFilePath + "'", e);
                     } catch (IOException e) {
                         getServletContext().log(
                                 "ERROR: Could not read the policy file '"
                                         + serializationPolicyFilePath + "'", e);
                     }
                 } else {
                     String message = "ERROR: The serialization policy file '"
                             + serializationPolicyFilePath
                             + "' was not found; did you forget to include it in this deployment?";
                     getServletContext().log(message);
                 }
             } finally {
                 if (is != null) {
                     try {
                         is.close();
                     } catch (IOException e) {
                         // Ignore this error
                     }
                 }
             }
         }

         return serializationPolicy;
     }

     /**
      * Allows the extending OSGi service to set the bundle it is part of. The bundle is used to provide access
      * to the policy file otherwise loaded by <code>getServletContext().getResourceAsStream()</code> which is not
      * supported in Sling.
      *
      * @param bundle The bundle to load the resource (policy file) from.
      */
     protected void setBundle(Bundle bundle) {
         this.bundle = bundle;
     }

     /**
      * Allows the extending OSGi service to set its classloader.
      *
      * @param classLoader The classloader to provide to the SlingRemoteServiceServlet.
      */
     protected void setClassLoader(ClassLoader classLoader) {
         this.classLoader = classLoader;
     }
 }
	/*
	* 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.sling.extensions.gwt.user.server.rpc;

	import com.google.gwt.user.client.rpc.SerializationException;
	import com.google.gwt.user.server.rpc.RemoteServiceServlet;
	import com.google.gwt.user.server.rpc.SerializationPolicy;
	import com.google.gwt.user.server.rpc.SerializationPolicyLoader;
	import org.osgi.framework.Bundle;

	import javax.servlet.http.HttpServletRequest;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.text.ParseException;

	/**
	* Extending google's remote service servlet to enable resolving of resources through
	* a bundle (for policy file loading).
	* <p/>
	* This class is for version 2.0.3 of the GWT gwt-servlet.jar edition and it is highly recommended to compile
	* client apps with the corresponding 2.0.3 GWT gwt-user.jar only!
	* <p/>
	* GWT service servlets that are used in sling are required to extend the <code>SlingRemoteServiceServlet</code>
	* instead of google's own <code>RemoteServiceServlet</code>.
	* </code>
	*/
	public class SlingRemoteServiceServlet extends RemoteServiceServlet {

	/**
	* The <code>org.osgi.framework.Bundle</code> to load resources from.
	*/
	private Bundle bundle;

	/**
	* The <code>ClassLoader</code> to use when GWT reflects on RPC classes.
	*/
	private ClassLoader classLoader;

	/**
	* Process a call originating from the given request. Uses the
	* {@link com.google.gwt.user.server.rpc.RPC#invokeAndEncodeResponse(Object, java.lang.reflect.Method, Object[])}
	* method to do the actual work.
	* <p>
	* Subclasses may optionally override this method to handle the payload in any
	* way they desire (by routing the request to a framework component, for
	* instance). The {@link javax.servlet.http.HttpServletRequest} and {@link javax.servlet.http.HttpServletResponse}
	* can be accessed via the {@link #getThreadLocalRequest()} and
	* {@link #getThreadLocalResponse()} methods.
	* </p>
	* This is public so that it can be unit tested easily without HTTP.
	* <p/>
	* In order to properly operate within Sling/OSGi, the classloader used by GWT has to be rerouted from
	* <code>Thread.currentThread().getContextClassLoader()</code> to the classloader provided by the bundle.
	*
	* @param payload the UTF-8 request payload
	* @return a string which encodes either the method's return, a checked
	* exception thrown by the method, or an
	* {@link com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException}
	* @throws com.google.gwt.user.client.rpc.SerializationException
	* if we cannot serialize the response
	* @throws com.google.gwt.user.server.rpc.UnexpectedException
	* if the invocation throws a checked exception
	* that is not declared in the service method's signature
	* @throws RuntimeException if the service method throws an unchecked
	* exception (the exception will be the one thrown by the service)
	*/
	@Override
	public String processCall(String payload) throws SerializationException {
	String result;
	if (classLoader != null) {
	final ClassLoader old = Thread.currentThread().getContextClassLoader();
	Thread.currentThread().setContextClassLoader(classLoader);
	result = super.processCall(payload);
	Thread.currentThread().setContextClassLoader(old);
	} else {
	result = super.processCall(payload);
	}
	return result;
	}

	/**
	* Gets the {@link com.google.gwt.user.server.rpc.SerializationPolicy} for given module base URL and strong
	* name if there is one.
	* <p/>
	* Override this method to provide a {@link com.google.gwt.user.server.rpc.SerializationPolicy} using an
	* alternative approach.
	* <p/>
	* This method has been overriden, so that the serialization policy can be properly loaded as a bundle entry,
	* as Sling does not support <code>ServletContext.getResourceAsStream()</code>.
	*
	* @param request the HTTP request being serviced
	* @param moduleBaseURL as specified in the incoming payload
	* @param strongName a strong name that uniquely identifies a serialization
	* policy file
	* @return a {@link com.google.gwt.user.server.rpc.SerializationPolicy} for the given module base URL and
	* strong name, or <code>null</code> if there is none
	*/
	@Override
	protected SerializationPolicy doGetSerializationPolicy(HttpServletRequest request, String moduleBaseURL, String strongName) {

	// The request can tell you the path of the web app relative to the
	// container root.
	String contextPath = request.getContextPath();

	String modulePath = null;
	if (moduleBaseURL != null) {
	try {
	modulePath = new URL(moduleBaseURL).getPath();
	} catch (MalformedURLException ex) {
	// log the information, we will default
	getServletContext().log("Malformed moduleBaseURL: " + moduleBaseURL, ex);
	}
	}

	SerializationPolicy serializationPolicy = null;

	/*
	* Check that the module path must be in the same web app as the servlet
	* itself. If you need to implement a scheme different than this, override
	* this method.
	*/
	if (modulePath == null \|\| !modulePath.startsWith(contextPath)) {
	String message = "ERROR: The module path requested, "
	+ modulePath
	+ ", is not in the same web application as this servlet, "
	+ contextPath
	+ ". Your module may not be properly configured or your client and server code maybe out of date.";
	getServletContext().log(message);
	} else {
	// Strip off the context path from the module base URL. It should be a
	// strict prefix.
	String contextRelativePath = modulePath.substring(contextPath.length());

	String serializationPolicyFilePath = SerializationPolicyLoader.getSerializationPolicyFileName(contextRelativePath
	+ strongName);

	// Open the RPC resource file read its contents.
	InputStream is = null;
	// if the bundle was set by the extending class, load the resource from it instead of the servlet context
	if (bundle != null) {
	try {
	is = bundle.getResource(serializationPolicyFilePath).openStream();
	} catch (IOException e) {
	//ignore
	}
	} else {
	is = getServletContext().getResourceAsStream(
	serializationPolicyFilePath);
	}
	try {
	if (is != null) {
	try {
	serializationPolicy = SerializationPolicyLoader.loadFromStream(is, null);
	} catch (ParseException e) {
	getServletContext().log(
	"ERROR: Failed to parse the policy file '"
	+ serializationPolicyFilePath + "'", e);
	} catch (IOException e) {
	getServletContext().log(
	"ERROR: Could not read the policy file '"
	+ serializationPolicyFilePath + "'", e);
	}
	} else {
	String message = "ERROR: The serialization policy file '"
	+ serializationPolicyFilePath
	+ "' was not found; did you forget to include it in this deployment?";
	getServletContext().log(message);
	}
	} finally {
	if (is != null) {
	try {
	is.close();
	} catch (IOException e) {
	// Ignore this error
	}
	}
	}
	}

	return serializationPolicy;
	}

	/**
	* Allows the extending OSGi service to set the bundle it is part of. The bundle is used to provide access
	* to the policy file otherwise loaded by <code>getServletContext().getResourceAsStream()</code> which is not
	* supported in Sling.
	*
	* @param bundle The bundle to load the resource (policy file) from.
	*/
	protected void setBundle(Bundle bundle) {
	this.bundle = bundle;
	}

	/**
	* Allows the extending OSGi service to set its classloader.
	*
	* @param classLoader The classloader to provide to the SlingRemoteServiceServlet.
	*/
	protected void setClassLoader(ClassLoader classLoader) {
	this.classLoader = classLoader;
	}
	}