org.mortbay.resource.URLResource Maven / Gradle / Ivy
// ========================================================================
// 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.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.security.Permission;
import org.mortbay.log.Log;
import org.mortbay.util.URIUtil;
/* ------------------------------------------------------------ */
/** Abstract resource class.
*
* @author Nuno Pregui�a
* @author Greg Wilkins (gregw)
*/
public class URLResource extends Resource
{
protected URL _url;
protected String _urlString;
protected transient URLConnection _connection;
protected transient InputStream _in=null;
transient boolean _useCaches = Resource.__defaultUseCaches;
/* ------------------------------------------------------------ */
protected URLResource(URL url, URLConnection connection)
{
_url = url;
_urlString=_url.toString();
_connection=connection;
}
protected URLResource (URL url, URLConnection connection, boolean useCaches)
{
this (url, connection);
_useCaches = useCaches;
}
/* ------------------------------------------------------------ */
protected synchronized boolean checkConnection()
{
if (_connection==null)
{
try{
_connection=_url.openConnection();
_connection.setUseCaches(_useCaches);
}
catch(IOException e)
{
Log.ignore(e);
}
}
return _connection!=null;
}
/* ------------------------------------------------------------ */
/** Release any resources held by the resource.
*/
public synchronized void release()
{
if (_in!=null)
{
try{_in.close();}catch(IOException e){Log.ignore(e);}
_in=null;
}
if (_connection!=null)
_connection=null;
}
/* ------------------------------------------------------------ */
/**
* Returns true if the respresened resource exists.
*/
public boolean exists()
{
try
{
synchronized(this)
{
if (checkConnection() && _in==null )
_in = _connection.getInputStream();
}
}
catch (IOException e)
{
Log.ignore(e);
}
return _in!=null;
}
/* ------------------------------------------------------------ */
/**
* Returns true if the respresenetd resource is a container/directory.
* If the resource is not a file, resources ending with "/" are
* considered directories.
*/
public boolean isDirectory()
{
return exists() && _url.toString().endsWith("/");
}
/* ------------------------------------------------------------ */
/**
* Returns the last modified time
*/
public long lastModified()
{
if (checkConnection())
return _connection.getLastModified();
return -1;
}
/* ------------------------------------------------------------ */
/**
* Return the length of the resource
*/
public long length()
{
if (checkConnection())
return _connection.getContentLength();
return -1;
}
/* ------------------------------------------------------------ */
/**
* Returns an URL representing the given resource
*/
public URL getURL()
{
return _url;
}
/* ------------------------------------------------------------ */
/**
* Returns an File representing the given resource or NULL if this
* is not possible.
*/
public File getFile()
throws IOException
{
// Try the permission hack
if (checkConnection())
{
Permission perm = _connection.getPermission();
if (perm instanceof java.io.FilePermission)
return new File(perm.getName());
}
// Try the URL file arg
try {return new File(_url.getFile());}
catch(Exception e) {Log.ignore(e);}
// Don't know the file
return null;
}
/* ------------------------------------------------------------ */
/**
* Returns the name of the resource
*/
public String getName()
{
return _url.toExternalForm();
}
/* ------------------------------------------------------------ */
/**
* Returns an input stream to the resource
*/
public synchronized InputStream getInputStream()
throws java.io.IOException
{
if (!checkConnection())
throw new IOException( "Invalid resource");
try
{
if( _in != null)
{
InputStream in = _in;
_in=null;
return in;
}
return _connection.getInputStream();
}
finally
{
_connection=null;
}
}
/* ------------------------------------------------------------ */
/**
* Returns an output stream to the resource
*/
public OutputStream getOutputStream()
throws java.io.IOException, SecurityException
{
throw new IOException( "Output not supported");
}
/* ------------------------------------------------------------ */
/**
* Deletes the given resource
*/
public boolean delete()
throws SecurityException
{
throw new SecurityException( "Delete not supported");
}
/* ------------------------------------------------------------ */
/**
* Rename the given resource
*/
public boolean renameTo( Resource dest)
throws SecurityException
{
throw new SecurityException( "RenameTo not supported");
}
/* ------------------------------------------------------------ */
/**
* Returns a list of resource names contained in the given resource
*/
public String[] list()
{
return null;
}
/* ------------------------------------------------------------ */
/**
* Returns the resource contained inside the current resource with the
* given name
*/
public Resource addPath(String path)
throws IOException,MalformedURLException
{
if (path==null)
return null;
path = URIUtil.canonicalPath(path);
return newResource(URIUtil.addPaths(_url.toExternalForm(),path));
}
/* ------------------------------------------------------------ */
public String toString()
{
return _urlString;
}
/* ------------------------------------------------------------ */
public int hashCode()
{
return _url.hashCode();
}
/* ------------------------------------------------------------ */
public boolean equals( Object o)
{
return o instanceof URLResource &&
_url.equals(((URLResource)o)._url);
}
public boolean getUseCaches ()
{
return _useCaches;
}
}