webconsole/gogo/src/main/java/org/apache/felix/karaf/webconsole/gogo/AbstractResourceAwareWebConsolePlugin.java - felix-dev - Git at Google

 /*
  *  Copyright 2009 Marcin.
  *
  *  Licensed 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.
  *  under the License.
  */
 package org.apache.felix.karaf.webconsole.gogo;

 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.lang.reflect.InvocationTargetException;
 import java.net.URL;
 import java.net.URLConnection;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.OutputStream;
 import java.io.InputStream;

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

 import org.apache.felix.webconsole.AbstractWebConsolePlugin;

 /**
  * TODO: remove this class when upgrading to webconsole 1.2.12
  */
 public abstract class AbstractResourceAwareWebConsolePlugin extends AbstractWebConsolePlugin {

     public static final String GET_RESOURCE_METHOD_NAME = "getResource";

     private final Method getResourceMethod;

     {
         getResourceMethod = getGetResourceMethod();
     }

     /**
      * Renders the web console page for the request. This consist of the following
      * five parts called in order:
      * <ol>
      * <li>Send back a requested resource
      * <li>{@link #startResponse(HttpServletRequest, HttpServletResponse)}</li>
      * <li>{@link #renderTopNavigation(HttpServletRequest, PrintWriter)}</li>
      * <li>{@link #renderContent(HttpServletRequest, HttpServletResponse)}</li>
      * <li>{@link #endResponse(PrintWriter)}</li>
      * </ol>
      * <p>
      * <b>Note</b>: If a resource is sent back for the request only the first
      * step is executed. Otherwise the first step is a null-operation actually
      * and the latter four steps are executed in order.
      */
     protected void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException,
             IOException
     {
         if ( !spoolResource( request, response ) )
         {
             PrintWriter pw = startResponse( request, response );
             renderTopNavigation( request, pw );
             renderContent( request, response );
             endResponse( pw );
         }
     }

     protected Object getResourceProvider() {
         return this;
     }

     /**
      * Returns a method which is called on the
      * {@link #getResourceProvider() resource provder} class to return an URL
      * to a resource which may be spooled when requested. The method has the
      * following signature:
      * <pre>
      * [modifier] URL getResource(String path);
      * </pre>
      * Where the <i>[modifier]</i> may be <code>public</code>, <code>protected</code>
      * or <code>private</code> (if the method is declared in the class of the
      * resource provider). It is suggested to use the <code>private</code>
      * modifier if the method is declared in the resource provider class or
      * the <code>protected</code> modifier if the method is declared in a
      * base class of the resource provider.
      *
      * @return The <code>getResource(String)</code> method or <code>null</code>
      *      if the {@link #getResourceProvider() resource provider} is
      *      <code>null</code> or does not provide such a method.
      */
     private Method getGetResourceMethod()
     {
         Method tmpGetResourceMethod = null;

         Object resourceProvider = getResourceProvider();
         if ( resourceProvider != null )
         {
             try
             {
                 Class cl = resourceProvider.getClass();
                 while ( tmpGetResourceMethod == null && cl != Object.class )
                 {
                     Method[] methods = cl.getDeclaredMethods();
                     for ( int i = 0; i < methods.length; i++ )
                     {
                         Method m = methods[i];
                         if ( GET_RESOURCE_METHOD_NAME.equals( m.getName() ) && m.getParameterTypes().length == 1
                             && m.getParameterTypes()[0] == String.class && m.getReturnType() == URL.class )
                         {
                             // ensure modifier is protected or public or the private
                             // method is defined in the plugin class itself
                             int mod = m.getModifiers();
                             if ( Modifier.isProtected( mod ) || Modifier.isPublic( mod )
                                 || ( Modifier.isPrivate( mod ) && cl == resourceProvider.getClass() ) )
                             {
                                 m.setAccessible( true );
                                 tmpGetResourceMethod = m;
                                 break;
                             }
                         }
                     }
                     cl = cl.getSuperclass();
                 }
             }
             catch ( Throwable t )
             {
                 tmpGetResourceMethod = null;
             }
         }

         return tmpGetResourceMethod;
     }

     /**
      * If the request addresses a resource which may be served by the
      * <code>getResource</code> method of the
      * {@link #getResourceProvider() resource provider}, this method serves it
      * and returns <code>true</code>. Otherwise <code>false</code> is returned.
      * <code>false</code> is also returned if the resource provider has no
      * <code>getResource</code> method.
      * <p>
      * If <code>true</code> is returned, the request is considered complete and
      * request processing terminates. Otherwise request processing continues
      * with normal plugin rendering.
      *
      * @param request The request object
      * @param response The response object
      * @return <code>true</code> if the request causes a resource to be sent back.
      *
      * @throws IOException If an error occurrs accessing or spooling the resource.
      */
     private boolean spoolResource( HttpServletRequest request, HttpServletResponse response ) throws IOException
     {
         // no resource if no resource accessor
         if ( getResourceMethod == null )
         {
             return false;
         }

         String pi = request.getPathInfo();
         InputStream ins = null;
         try
         {

             // check for a resource, fail if none
             URL url = ( URL ) getResourceMethod.invoke( getResourceProvider(), new Object[]
                 { pi } );
             if ( url == null )
             {
                 return false;
             }

             // open the connection and the stream (we use the stream to be able
             // to at least hint to close the connection because there is no
             // method to explicitly close the conneciton, unfortunately)
             URLConnection connection = url.openConnection();
             ins = connection.getInputStream();

             // check whether we may return 304/UNMODIFIED
             long lastModified = connection.getLastModified();
             if ( lastModified > 0 )
             {
                 long ifModifiedSince = request.getDateHeader( "If-Modified-Since" );
                 if ( ifModifiedSince >= ( lastModified / 1000 * 1000 ) )
                 {
                     // Round down to the nearest second for a proper compare
                     // A ifModifiedSince of -1 will always be less
                     response.setStatus( HttpServletResponse.SC_NOT_MODIFIED );

                     return true;
                 }

                 // have to send, so set the last modified header now
                 response.setDateHeader( "Last-Modified", lastModified );
             }

             // describe the contents
             response.setContentType( getServletContext().getMimeType( pi ) );
             response.setIntHeader( "Content-Length", connection.getContentLength() );

             // spool the actual contents
             OutputStream out = response.getOutputStream();
             byte[] buf = new byte[2048];
             int rd;
             while ( ( rd = ins.read( buf ) ) >= 0 )
             {
                 out.write( buf, 0, rd );
             }

             // over and out ...
             return true;
         }
         catch ( IllegalAccessException iae )
         {
             // log or throw ???
         }
         catch ( InvocationTargetException ite )
         {
             // log or throw ???
             // Throwable cause = ite.getTargetException();
         }
       finally
         {
             if ( ins != null )
             {
                 try
                 {
                     ins.close();
                 }
                 catch ( IOException ignore )
                 {
                 }
             }
         }

         return false;
     }


 }
	/*
	* Copyright 2009 Marcin.
	*
	* Licensed 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.
	* under the License.
	*/
	package org.apache.felix.karaf.webconsole.gogo;

	import java.lang.reflect.Method;
	import java.lang.reflect.Modifier;
	import java.lang.reflect.InvocationTargetException;
	import java.net.URL;
	import java.net.URLConnection;
	import java.io.IOException;
	import java.io.PrintWriter;
	import java.io.OutputStream;
	import java.io.InputStream;

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

	import org.apache.felix.webconsole.AbstractWebConsolePlugin;

	/**
	* TODO: remove this class when upgrading to webconsole 1.2.12
	*/
	public abstract class AbstractResourceAwareWebConsolePlugin extends AbstractWebConsolePlugin {

	public static final String GET_RESOURCE_METHOD_NAME = "getResource";

	private final Method getResourceMethod;

	{
	getResourceMethod = getGetResourceMethod();
	}

	/**
	* Renders the web console page for the request. This consist of the following
	* five parts called in order:
	* <ol>
	* <li>Send back a requested resource
	* <li>{@link #startResponse(HttpServletRequest, HttpServletResponse)}</li>
	* <li>{@link #renderTopNavigation(HttpServletRequest, PrintWriter)}</li>
	* <li>{@link #renderContent(HttpServletRequest, HttpServletResponse)}</li>
	* <li>{@link #endResponse(PrintWriter)}</li>
	* </ol>
	* <p>
	* <b>Note</b>: If a resource is sent back for the request only the first
	* step is executed. Otherwise the first step is a null-operation actually
	* and the latter four steps are executed in order.
	*/
	protected void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException,
	IOException
	{
	if ( !spoolResource( request, response ) )
	{
	PrintWriter pw = startResponse( request, response );
	renderTopNavigation( request, pw );
	renderContent( request, response );
	endResponse( pw );
	}
	}

	protected Object getResourceProvider() {
	return this;
	}

	/**
	* Returns a method which is called on the
	* {@link #getResourceProvider() resource provder} class to return an URL
	* to a resource which may be spooled when requested. The method has the
	* following signature:
	* <pre>
	* [modifier] URL getResource(String path);
	* </pre>
	* Where the <i>[modifier]</i> may be <code>public</code>, <code>protected</code>
	* or <code>private</code> (if the method is declared in the class of the
	* resource provider). It is suggested to use the <code>private</code>
	* modifier if the method is declared in the resource provider class or
	* the <code>protected</code> modifier if the method is declared in a
	* base class of the resource provider.
	*
	* @return The <code>getResource(String)</code> method or <code>null</code>
	* if the {@link #getResourceProvider() resource provider} is
	* <code>null</code> or does not provide such a method.
	*/
	private Method getGetResourceMethod()
	{
	Method tmpGetResourceMethod = null;

	Object resourceProvider = getResourceProvider();
	if ( resourceProvider != null )
	{
	try
	{
	Class cl = resourceProvider.getClass();
	while ( tmpGetResourceMethod == null && cl != Object.class )
	{
	Method[] methods = cl.getDeclaredMethods();
	for ( int i = 0; i < methods.length; i++ )
	{
	Method m = methods[i];
	if ( GET_RESOURCE_METHOD_NAME.equals( m.getName() ) && m.getParameterTypes().length == 1
	&& m.getParameterTypes()[0] == String.class && m.getReturnType() == URL.class )
	{
	// ensure modifier is protected or public or the private
	// method is defined in the plugin class itself
	int mod = m.getModifiers();
	if ( Modifier.isProtected( mod ) \|\| Modifier.isPublic( mod )
	\|\| ( Modifier.isPrivate( mod ) && cl == resourceProvider.getClass() ) )
	{
	m.setAccessible( true );
	tmpGetResourceMethod = m;
	break;
	}
	}
	}
	cl = cl.getSuperclass();
	}
	}
	catch ( Throwable t )
	{
	tmpGetResourceMethod = null;
	}
	}

	return tmpGetResourceMethod;
	}

	/**
	* If the request addresses a resource which may be served by the
	* <code>getResource</code> method of the
	* {@link #getResourceProvider() resource provider}, this method serves it
	* and returns <code>true</code>. Otherwise <code>false</code> is returned.
	* <code>false</code> is also returned if the resource provider has no
	* <code>getResource</code> method.
	* <p>
	* If <code>true</code> is returned, the request is considered complete and
	* request processing terminates. Otherwise request processing continues
	* with normal plugin rendering.
	*
	* @param request The request object
	* @param response The response object
	* @return <code>true</code> if the request causes a resource to be sent back.
	*
	* @throws IOException If an error occurrs accessing or spooling the resource.
	*/
	private boolean spoolResource( HttpServletRequest request, HttpServletResponse response ) throws IOException
	{
	// no resource if no resource accessor
	if ( getResourceMethod == null )
	{
	return false;
	}

	String pi = request.getPathInfo();
	InputStream ins = null;
	try
	{

	// check for a resource, fail if none
	URL url = ( URL ) getResourceMethod.invoke( getResourceProvider(), new Object[]
	{ pi } );
	if ( url == null )
	{
	return false;
	}

	// open the connection and the stream (we use the stream to be able
	// to at least hint to close the connection because there is no
	// method to explicitly close the conneciton, unfortunately)
	URLConnection connection = url.openConnection();
	ins = connection.getInputStream();

	// check whether we may return 304/UNMODIFIED
	long lastModified = connection.getLastModified();
	if ( lastModified > 0 )
	{
	long ifModifiedSince = request.getDateHeader( "If-Modified-Since" );
	if ( ifModifiedSince >= ( lastModified / 1000 * 1000 ) )
	{
	// Round down to the nearest second for a proper compare
	// A ifModifiedSince of -1 will always be less
	response.setStatus( HttpServletResponse.SC_NOT_MODIFIED );

	return true;
	}

	// have to send, so set the last modified header now
	response.setDateHeader( "Last-Modified", lastModified );
	}

	// describe the contents
	response.setContentType( getServletContext().getMimeType( pi ) );
	response.setIntHeader( "Content-Length", connection.getContentLength() );

	// spool the actual contents
	OutputStream out = response.getOutputStream();
	byte[] buf = new byte[2048];
	int rd;
	while ( ( rd = ins.read( buf ) ) >= 0 )
	{
	out.write( buf, 0, rd );
	}

	// over and out ...
	return true;
	}
	catch ( IllegalAccessException iae )
	{
	// log or throw ???
	}
	catch ( InvocationTargetException ite )
	{
	// log or throw ???
	// Throwable cause = ite.getTargetException();
	}
	finally
	{
	if ( ins != null )
	{
	try
	{
	ins.close();
	}
	catch ( IOException ignore )
	{
	}
	}
	}

	return false;
	}


	}