java/src/main/com/google/appengine/tools/development/PrivilegedJspServlet.java

   1 // Copyright 2009 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.tools.development;
   4
   5 import org.apache.jasper.servlet.JspServlet;
   6 import java.security.AccessController;
   7 import java.security.PrivilegedExceptionAction;
   8 import java.security.PrivilegedActionException;
   9
  10 import javax.servlet.ServletException;
  11 import javax.servlet.ServletConfig;
  12 import javax.servlet.http.HttpServletRequest;
  13 import javax.servlet.http.HttpServletResponse;
  14
  15 import java.io.IOException;
  16
  17 /**
  18  * {@code PrivilegedJspServlet} wraps the Jasper {@link JspServlet}
  19  * with {@code doPrivileged} blocks.
  20  *
  21  */
  22 public class PrivilegedJspServlet extends JspServlet {
  23
  24   /**
  25    * The request attribute that contains the name of the JSP file, when the
  26    * request path doesn't refer directly to the JSP file (for example,
  27    * it's instead a servlet mapping).
  28    */
  29   private static final String JASPER_JSP_FILE = "org.apache.catalina.jsp_file";
  30
  31   @Override
  32   public void init(final ServletConfig config) throws ServletException {
  33     try {
  34       AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
  35         @Override
  36         public Object run() throws ServletException {
  37           PrivilegedJspServlet.super.init(config);
  38           return null;
  39         }
  40       });
  41     } catch (PrivilegedActionException ex) {
  42       Throwable cause = ex.getException();
  43       if (cause instanceof ServletException) {
  44         throw (ServletException) cause;
  45       } else {
  46         throw new RuntimeException(cause);
  47       }
  48     }
  49   }
  50
  51   @Override
  52   public void service (final HttpServletRequest request, final HttpServletResponse response)
  53       throws ServletException, IOException {
  54     fixupJspFileAttribute(request);
  55
  56     try {
  57       AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
  58         @Override
  59           public Object run() throws IOException, ServletException {
  60             PrivilegedJspServlet.super.service(request, response);
  61             return null;
  62           }
  63       });
  64     } catch (PrivilegedActionException ex) {
  65       Throwable cause = ex.getException();
  66       if (cause instanceof IOException) {
  67         throw (IOException) cause;
  68       } else if (cause instanceof ServletException) {
  69         throw (ServletException) cause;
  70       } else {
  71         throw new RuntimeException(cause);
  72       }
  73     }
  74   }
  75
  76   private void fixupJspFileAttribute(HttpServletRequest request) {
  77     String jspFile = (String)request.getAttribute(JASPER_JSP_FILE);
  78
  79     if (jspFile != null) {
  80       if (jspFile.length() == 0) {
  81         jspFile = "/";
  82       } else if (jspFile.charAt(0) != '/') {
  83         jspFile = "/" + jspFile;
  84       }
  85       request.setAttribute(JASPER_JSP_FILE, jspFile);
  86     }
  87   }
  88 }