Jetty example source code file (JarFileResource.java)

This example Jetty source code file (JarFileResource.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Jetty tags/keywords

arraylist, enumeration, file, io, jar, jarentry, jarentry, jarfile, jarfile, jarfileresource, jarfileresource, jarresource, jarurlconnection, net, network, resource, string, string, util

The Jetty JarFileResource.java source code

// ========================================================================
// Copyright 1996-2005 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// 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.
// ========================================================================
package org.mortbay.resource;

import java.io.File;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import org.mortbay.log.Log;

/* ------------------------------------------------------------ */
class JarFileResource extends JarResource
{
    
    transient JarFile _jarFile;
    transient File _file;
    transient String[] _list;
    transient JarEntry _entry;
    transient boolean _directory;
    transient String _jarUrl;
    transient String _path;
    transient boolean _exists;

    
    /* -------------------------------------------------------- */
    JarFileResource(URL url)
    {
        super(url);
    }
    
    JarFileResource(URL url, boolean useCaches)
    {
        super(url, useCaches);
    }
   

    /* ------------------------------------------------------------ */
    public synchronized void release()
    {
        _list=null;
        _entry=null;
        _file=null;
        _jarFile=null;
        super.release();
    }
    
    /* ------------------------------------------------------------ */
    protected boolean checkConnection()
    {
        try{
            super.checkConnection();
        }
        finally
        {
            if (_jarConnection==null)
            {
                _entry=null;
                _file=null;
                _jarFile=null;
                _list=null;
            }
        }
        return _jarFile!=null;
    }


    /* ------------------------------------------------------------ */
    protected void newConnection()
        throws IOException
    {
        super.newConnection();
        
        _entry=null;
        _file=null;
        _jarFile=null;
        _list=null;
        
        int sep = _urlString.indexOf("!/");
        _jarUrl=_urlString.substring(0,sep+2);
        _path=_urlString.substring(sep+2);
        if (_path.length()==0)
            _path=null;   
        _jarFile=_jarConnection.getJarFile();
        _file=new File(_jarFile.getName());
    }
    
    
    /* ------------------------------------------------------------ */
    /**
     * Returns true if the respresenetd resource exists.
     */
    public boolean exists()
    {
        if (_exists)
            return true;

        if (_urlString.endsWith("!/"))
        {
            
            String file_url=_urlString.substring(4,_urlString.length()-2);
            try{return newResource(file_url).exists();}
            catch(Exception e) {Log.ignore(e); return false;}
        }
        
        boolean check=checkConnection();
        
        // Is this a root URL?
        if (_jarUrl!=null && _path==null)
        {
            // Then if it exists it is a directory
            _directory=check;
            return true;
        }
        else 
        {
            // Can we find a file for it?
            JarFile jarFile=null;
            if (check)
                // Yes
                jarFile=_jarFile;
            else
            {
                // No - so lets look if the root entry exists.
                try
                {
                    JarURLConnection c=(JarURLConnection)((new URL(_jarUrl)).openConnection());
                    c.setUseCaches(getUseCaches());
                    jarFile=c.getJarFile();
                }
                catch(Exception e)
                {
                       Log.ignore(e);
                }
            }

            // Do we need to look more closely?
            if (jarFile!=null && _entry==null && !_directory)
            {
                // OK - we have a JarFile, lets look at the entries for our path
                Enumeration e=jarFile.entries();
                while(e.hasMoreElements())
                {
                    JarEntry entry = (JarEntry) e.nextElement();
                    String name=entry.getName().replace('\\','/');
                    
                    // Do we have a match
                    if (name.equals(_path))
                    {
                        _entry=entry;
                        // Is the match a directory
                        _directory=_path.endsWith("/");
                        break;
                    }
                    else if (_path.endsWith("/"))
                    {
                        if (name.startsWith(_path))
                        {
                            _directory=true;
                            break;
                        }
                    }
                    else if (name.startsWith(_path) && name.length()>_path.length() && name.charAt(_path.length())=='/')
                    {
                        _directory=true;
                        break;
                    }
                }
            }
        }    
        
        _exists= ( _directory || _entry!=null);
        return _exists;
    }

    
    /* ------------------------------------------------------------ */
    /**
     * Returns true if the represented resource is a container/directory.
     * If the resource is not a file, resources ending with "/" are
     * considered directories.
     */
    public boolean isDirectory()
    {
        return _urlString.endsWith("/") || exists() && _directory;
    }
    
    /* ------------------------------------------------------------ */
    /**
     * Returns the last modified time
     */
    public long lastModified()
    {
        if (checkConnection() && _file!=null)
            return _file.lastModified();
        return -1;
    }

    /* ------------------------------------------------------------ */
    public synchronized String[] list()
    {
        
        if(isDirectory() && _list==null)
        {
            ArrayList list = new ArrayList(32);

            checkConnection();
            
            JarFile jarFile=_jarFile;
            if(jarFile==null)
            {
                try
                {
                    JarURLConnection jc=(JarURLConnection)((new URL(_jarUrl)).openConnection());
                    jc.setUseCaches(getUseCaches());
                    jarFile=jc.getJarFile();
                }
                catch(Exception e)
                {
                     Log.ignore(e);
                }
            }
            
            Enumeration e=jarFile.entries();
            String dir=_urlString.substring(_urlString.indexOf("!/")+2);
            while(e.hasMoreElements())
            {
                
                JarEntry entry = (JarEntry) e.nextElement();               
                String name=entry.getName().replace('\\','/');               
                if(!name.startsWith(dir) || name.length()==dir.length())
                {
                    continue;
                }
                String listName=name.substring(dir.length());               
                int dash=listName.indexOf('/');
                if (dash>=0)
                {
                    //when listing jar:file urls, you get back one
                    //entry for the dir itself, which we ignore
                    if (dash==0 && listName.length()==1)
                        continue;
                    //when listing jar:file urls, all files and
                    //subdirs have a leading /, which we remove
                    if (dash==0)
                        listName=listName.substring(dash+1, listName.length());
                    else
                        listName=listName.substring(0,dash+1);
                    
                    if (list.contains(listName))
                        continue;
                }
                
                list.add(listName);
            }
            
            _list=new String[list.size()];
            list.toArray(_list);
        }
        return _list;
    }
    
    /* ------------------------------------------------------------ */
    /**
     * Return the length of the resource
     */
    public long length()
    {
        if (isDirectory())
            return -1;

        if (_entry!=null)
            return _entry.getSize();
        
        return -1;
    }
    
    /* ------------------------------------------------------------ */
    /** Encode according to this resource type.
     * File URIs are not encoded.
     * @param uri URI to encode.
     * @return The uri unchanged.
     */
    public String encode(String uri)
    {
        return uri;
    }

    
    /**
     * Take a Resource that possibly might use URLConnection caching
     * and turn it into one that doesn't.
     * @param resource
     * @return
     */
    public static Resource getNonCachingResource (Resource resource)
    {
        if (!(resource instanceof JarFileResource))
            return resource;
        
        JarFileResource oldResource = (JarFileResource)resource;
        
        JarFileResource newResource = new JarFileResource(oldResource.getURL(), false);
        return newResource;
        
    }
}