Docjar: org/roller/presentation/velocity/WebappResourceLoader.java

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Source code: org/roller/presentation/velocity/WebappResourceLoader.java

1   package org.roller.presentation.velocity;
2   
3   import org.apache.commons.collections.ExtendedProperties;
4   import org.apache.commons.logging.Log;
5   import org.apache.commons.logging.LogFactory;
6   import org.apache.velocity.exception.ResourceNotFoundException;
7   import org.apache.velocity.runtime.resource.Resource;
8   import org.apache.velocity.runtime.resource.loader.ResourceLoader;
9   import org.roller.presentation.RollerContext;
10  
11  import java.io.InputStream;
12  
13  import javax.servlet.ServletContext;
14  
15  /**
16   * Tries to load Velocity resources from the Webapp.
17   * This class borrows heavily from
18   * org.apache.velocity.tools.view.servlet.WebappLoader
19   * http://cvs.apache.org/viewcvs/jakarta-velocity-
20   * tools/view/src/java/org/apache/velocity/tools/view/servlet/WebappLoader.java?
21   * rev=1.1.1.1&content-type=text/vnd.viewcvs-markup
22   * 
23   * @author Lance Lavandowska
24   */
25  public class WebappResourceLoader extends ResourceLoader
26  {
27    private static Log mLogger = 
28      LogFactory.getFactory().getInstance(WebappResourceLoader.class);
29      
30      private static ServletContext mContext = null; 
31    
32    /**
33     * @see org.apache.velocity.runtime.resource.loader.ResourceLoader#init(org.apache.commons.collections.ExtendedProperties)
34     */
35    public void init(ExtendedProperties arg0)
36    {
37      rsvc.info("WebappResourceLoader : initialization starting.");
38  
39      this.getContext();
40      if (mContext == null)
41      {
42        mLogger.warn("WebappResourceLoader : Unable to find ServletContext!");
43      }
44  
45      rsvc.info("WebappResourceLoader : initialization complete.");
46    }
47    
48    private ServletContext getContext()
49    {
50      if (mContext == null)
51      {
52        mContext = RollerContext.getServletContext();
53      }
54      return mContext;
55    }
56    
57    public static void setServletContext(ServletContext context)
58    {
59      mContext = context;
60    }
61    
62    /**
63     * @see org.apache.velocity.runtime.resource.loader.ResourceLoader#getResourceStream(java.lang.String)
64     */
65    public InputStream getResourceStream(String name)
66      throws ResourceNotFoundException
67    {
68      InputStream result = null;
69          
70      if (name == null || name.length() == 0)
71      {
72        throw new ResourceNotFoundException ("No template name provided");
73      }
74          
75      try 
76      {
77        if (!name.startsWith("/"))
78          name = "/" + name;
79  
80        result = getContext().getResourceAsStream( name );
81      }
82      catch( NullPointerException npe)
83      {
84        String msg = "WebappResourceLoader.getResourceStream(): " + name;
85        if (mContext == null)
86        {
87          mLogger.info("WebappResourceLoader("+name+"): ServletContext is null");
88          msg += "\n\tServletContext is null";
89        }
90        throw new ResourceNotFoundException(msg);
91      }
92      catch( Exception fnfe )
93      {
94        /*
95         *  log and convert to a general Velocity ResourceNotFoundException
96         */            
97        throw new ResourceNotFoundException( fnfe.getMessage() );
98      }
99          
100     return result;
101   }
102   
103   /**
104    * Defaults to return false.
105    * @see org.apache.velocity.runtime.resource.loader.ResourceLoader#isSourceModified(org.apache.velocity.runtime.resource.Resource)
106    */
107   public boolean isSourceModified(Resource arg0)
108   {
109     return false;
110   }
111   
112   /**
113    * Defaults to return 0.
114    * @see org.apache.velocity.runtime.resource.loader.ResourceLoader#getLastModified(org.apache.velocity.runtime.resource.Resource)
115    */
116   public long getLastModified(Resource arg0)
117   {
118     return 0;
119   }
120 }