Jetty example source code file (JarResource.java)

This example Jetty source code file (JarResource.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

extract, file, file, fileoutputstream, inputstream, io, ioexception, ioexception, jar, jarinputstream, jarresource, jarresource, jarurlconnection, net, network, string, string, url

The Jetty JarResource.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.FileOutputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;

import org.mortbay.log.Log;
import org.mortbay.util.IO;


/* ------------------------------------------------------------ */
public class JarResource extends URLResource
{

    protected transient JarURLConnection _jarConnection;
    
    /* -------------------------------------------------------- */
    JarResource(URL url)
    {
        super(url,null);
    }

    /* ------------------------------------------------------------ */
    JarResource(URL url, boolean useCaches)
    {
        super(url, null, useCaches);
    }
    
    /* ------------------------------------------------------------ */
    public synchronized void release()
    {
        _jarConnection=null;
        super.release();
    }
    
    /* ------------------------------------------------------------ */
    protected boolean checkConnection()
    {
        super.checkConnection();
        try
        {
            if (_jarConnection!=_connection)
                newConnection();
        }
        catch(IOException e)
        {
            Log.ignore(e);
            _jarConnection=null;
        }
        
        return _jarConnection!=null;
    }

    /* ------------------------------------------------------------ */
    /**
     * @throws IOException Sub-classes of <code>JarResource may throw an IOException (or subclass) 
     */
    protected void newConnection() throws IOException
    {
        _jarConnection=(JarURLConnection)_connection;
    }
    
    /* ------------------------------------------------------------ */
    /**
     * Returns true if the respresenetd resource exists.
     */
    public boolean exists()
    {
        if (_urlString.endsWith("!/"))
            return checkConnection();
        else
            return super.exists();
    }    

    /* ------------------------------------------------------------ */
    public File getFile()
        throws IOException
    {
        return null;
    }
    
    /* ------------------------------------------------------------ */
    public InputStream getInputStream()
        throws java.io.IOException
    {     
        checkConnection();
        if (!_urlString.endsWith("!/"))
            return new FilterInputStream(super.getInputStream()) 
            {
                public void close() throws IOException {this.in=IO.getClosedStream();}
            };

        URL url = new URL(_urlString.substring(4,_urlString.length()-2));      
        InputStream is = url.openStream();
        return is;
    }
    
    /* ------------------------------------------------------------ */
    public static void extract(Resource resource, File directory, boolean deleteOnExit)
        throws IOException
    {
        if(Log.isDebugEnabled())Log.debug("Extract "+resource+" to "+directory);
        
        
        String urlString = resource.getURL().toExternalForm().trim();
        int endOfJarUrl = urlString.indexOf("!/");
        int startOfJarUrl = (endOfJarUrl >= 0?4:0);
        
        if (endOfJarUrl < 0)
            throw new IOException("Not a valid jar url: "+urlString);
        
        URL jarFileURL = new URL(urlString.substring(startOfJarUrl, endOfJarUrl));
        String subEntryName = (endOfJarUrl+2 < urlString.length() ? urlString.substring(endOfJarUrl + 2) : null);
        boolean subEntryIsDir = (subEntryName != null && subEntryName.endsWith("/")?true:false);
      
        if (Log.isDebugEnabled()) Log.debug("Extracting entry = "+subEntryName+" from jar "+jarFileURL);
        
        InputStream is = jarFileURL.openConnection().getInputStream();
        JarInputStream jin = new JarInputStream(is);
        JarEntry entry;
        boolean shouldExtract;
        while((entry=jin.getNextJarEntry())!=null)
        {
            String entryName = entry.getName();
           
            if ((subEntryName != null) && (entryName.startsWith(subEntryName)))
            { 
                //if there is a particular subEntry that we are looking for, only
                //extract it.
                if (subEntryIsDir)
                {
                    //if it is a subdirectory we are looking for, then we
                    //are looking to extract its contents into the target
                    //directory. Remove the name of the subdirectory so
                    //that we don't wind up creating it too.
                    entryName = entryName.substring(subEntryName.length());
                    if (!entryName.equals(""))
                    {
                        //the entry is 
                        shouldExtract = true;                   
                    }
                    else
                        shouldExtract = false;
                }
                else
                    shouldExtract = true;
            }
            else if ((subEntryName != null) && (!entryName.startsWith(subEntryName)))
            {
                //there is a particular entry we are looking for, and this one
                //isn't it
                shouldExtract = false;
            }
            else
            {
                //we are extracting everything
                shouldExtract =  true;
            }
                
            
            if (!shouldExtract)
            {
                if (Log.isDebugEnabled()) Log.debug("Skipping entry: "+entryName);
                continue;
            }
                
           
            File file=new File(directory,entryName);
            if (entry.isDirectory())
            {
                // Make directory
                if (!file.exists())
                    file.mkdirs();
            }
            else
            {
                // make directory (some jars don't list dirs)
                File dir = new File(file.getParent());
                if (!dir.exists())
                    dir.mkdirs();

                // Make file
                FileOutputStream fout = null;
                try
                {
                    fout = new FileOutputStream(file);
                    IO.copy(jin,fout);
                }
                finally
                {
                    IO.close(fout);
                }

                // touch the file.
                if (entry.getTime()>=0)
                    file.setLastModified(entry.getTime());
            }
            if (deleteOnExit)
                file.deleteOnExit();
        }
    }
    
    /* ------------------------------------------------------------ */
    public void extract(File directory, boolean deleteOnExit)
        throws IOException
    {
        extract(this,directory,deleteOnExit);
    }   
}