Coverage Report - org.mule.util.MuleUrlStreamHandlerFactory
 
Classes in this File Line Coverage Branch Coverage Complexity
MuleUrlStreamHandlerFactory
79%
22/28
50%
5/10
2.5
 
 1  
 /*
 2  
  * $Id: MuleUrlStreamHandlerFactory.java 7963 2007-08-21 08:53:15Z dirk.olmes $
 3  
  * --------------------------------------------------------------------------------------
 4  
  * Copyright (c) MuleSource, Inc.  All rights reserved.  http://www.mulesource.com
 5  
  *
 6  
  * The software in this package is published under the terms of the CPAL v1.0
 7  
  * license, a copy of which has been included with this distribution in the
 8  
  * LICENSE.txt file.
 9  
  */
 10  
 
 11  
 package org.mule.util;
 12  
 
 13  
 import java.net.URL;
 14  
 import java.net.URLStreamHandler;
 15  
 import java.net.URLStreamHandlerFactory;
 16  
 import java.util.Collections;
 17  
 import java.util.HashMap;
 18  
 import java.util.Map;
 19  
 import java.util.StringTokenizer;
 20  
 
 21  
 import org.apache.commons.logging.Log;
 22  
 import org.apache.commons.logging.LogFactory;
 23  
 
 24  
 /**
 25  
  * A factory for loading URL protocol handlers. This factory is necessary to make
 26  
  * Mule work in cases where the standard approach using system properties does not
 27  
  * work, e.g. in application servers or with maven's surefire tests.
 28  
  * <p>
 29  
  * Client classes can register a subclass of {@link URLStreamHandler} for a given
 30  
  * protocol. This implementation first checks its registered handlers before
 31  
  * resorting to the default mechanism.
 32  
  * <p>
 33  
  * @see java.net.URL#URL(String, String, int, String)
 34  
  */
 35  2
 public class MuleUrlStreamHandlerFactory extends Object implements URLStreamHandlerFactory
 36  
 {
 37  
     private static final String HANDLER_PKGS_SYSTEM_PROPERTY = "java.protocol.handler.pkgs";
 38  4
     private static final Log log = LogFactory.getLog(MuleUrlStreamHandlerFactory.class);
 39  
     
 40  2
     private static Map registry = Collections.synchronizedMap(new HashMap());
 41  
 
 42  
     /**
 43  
      * Install an instance of this class as UrlStreamHandlerFactory. This may be done exactly
 44  
      * once as {@link URL} will throw an {@link Error} on subsequent invocations. 
 45  
      * <p>
 46  
      * This method takes care that multiple invocations are possible, but the 
 47  
      * UrlStreamHandlerFactory is installed only once.
 48  
      */
 49  
     public static synchronized void installUrlStreamHandlerFactory()
 50  
     {
 51  
         /*
 52  
          * When running under surefire, this class will be loaded by different class loaders and
 53  
          * will be running in multiple "main" thread objects. Thus, there is no way for this class
 54  
          * to register a globally available variable to store the info whether our custom 
 55  
          * UrlStreamHandlerFactory was already registered.
 56  
          * 
 57  
          * The only way to accomplish this is to catch the Error that is thrown by URL when
 58  
          * trying to re-register the custom UrlStreamHandlerFactory.
 59  
          */
 60  
         try
 61  
         {
 62  2
             URL.setURLStreamHandlerFactory(new MuleUrlStreamHandlerFactory());
 63  
         }
 64  0
         catch (Error err)
 65  
         {
 66  0
             if (log.isDebugEnabled())
 67  
             {
 68  0
                 log.debug("Custom MuleUrlStreamHandlerFactory already registered", err);
 69  
             }
 70  2
         }
 71  2
     }
 72  
     
 73  
     public static void registerHandler(String protocol, URLStreamHandler handler)
 74  
     {
 75  0
         registry.put(protocol, handler);
 76  0
     }
 77  
 
 78  
     public URLStreamHandler createURLStreamHandler(String protocol)
 79  
     {
 80  6
         URLStreamHandler handler = (URLStreamHandler) registry.get(protocol);
 81  6
         if (handler == null)
 82  
         {
 83  6
             handler = this.defaultHandlerCreateStrategy(protocol);
 84  
         }
 85  6
         return handler;
 86  
     }
 87  
 
 88  
     private URLStreamHandler defaultHandlerCreateStrategy(String protocol)
 89  
     {
 90  6
         String packagePrefixList = System.getProperty(HANDLER_PKGS_SYSTEM_PROPERTY, "");
 91  
 
 92  6
         if (packagePrefixList.endsWith("|") == false)
 93  
         {
 94  6
             packagePrefixList += "|sun.net.www.protocol";
 95  
         }
 96  
 
 97  6
         StringTokenizer tokenizer = new StringTokenizer(packagePrefixList, "|");
 98  
 
 99  6
         URLStreamHandler handler = null;
 100  12
         while (handler == null && tokenizer.hasMoreTokens())
 101  
         {
 102  6
             String packagePrefix = tokenizer.nextToken().trim();
 103  6
             String className = packagePrefix + "." + protocol + ".Handler";
 104  
             try
 105  
             {
 106  6
                 handler = (URLStreamHandler) ClassUtils.instanciateClass(className, null);
 107  
             }
 108  0
             catch (Exception ex)
 109  
             {
 110  
                 // not much we can do here
 111  6
             }
 112  6
         }
 113  
          
 114  6
         return handler;
 115  
     }
 116  
 }