helma/src/Acme/Serve/FileServlet.java

316 lines
9.8 KiB
Java

// FileServlet - servlet similar to a standard httpd
//
// Copyright (C)1996,1998 by Jef Poskanzer <jef@acme.com>. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// Visit the ACME Labs Java page for up-to-date versions of this and other
// fine Java utilities: http://www.acme.com/java/
package Acme.Serve;
import java.io.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;
/// Servlet similar to a standard httpd.
// <P>
// Implements the "GET" and "HEAD" methods for files and directories.
// Handles index.html.
// Redirects directory URLs that lack a trailing /.
// Handles If-Modified-Since and Range.
// <P>
// <A HREF="/resources/classes/Acme/Serve/FileServlet.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>
// <P>
// @see Acme.Serve.Serve
public class FileServlet extends HttpServlet
{
// We keep a single throttle table for all instances of the servlet.
// Normally there is only one instance; the exception is subclasses.
static Acme.WildcardDictionary throttleTab = null;
/// Constructor.
public FileServlet()
{
}
/// Constructor with throttling.
// @param throttles filename containing throttle settings
// @see ThrottledOutputStream
public FileServlet( String throttles ) throws IOException
{
this();
readThrottles( throttles );
}
private void readThrottles( String throttles ) throws IOException
{
Acme.WildcardDictionary newThrottleTab =
ThrottledOutputStream.parseThrottleFile( throttles );
if ( throttleTab == null )
throttleTab = newThrottleTab;
else
{
// Merge the new one into the old one.
Enumeration keys = newThrottleTab.keys();
Enumeration elements = newThrottleTab.elements();
while ( keys.hasMoreElements() )
{
Object key = keys.nextElement();
Object element = elements.nextElement();
throttleTab.put( key, element );
}
}
}
/// Returns a string containing information about the author, version, and
// copyright of the servlet.
public String getServletInfo()
{
return "servlet similar to a standard httpd";
}
/// Services a single request from the client.
// @param req the servlet request
// @param req the servlet response
// @exception ServletException when an exception has occurred
public void service( HttpServletRequest req, HttpServletResponse res ) throws ServletException, IOException
{
boolean headOnly;
if ( req.getMethod().equalsIgnoreCase( "get" ) )
headOnly = false;
else if ( ! req.getMethod().equalsIgnoreCase( "head" ) )
headOnly = true;
else
{
res.sendError( HttpServletResponse.SC_NOT_IMPLEMENTED );
return;
}
String path = req.getServletPath();
if ( path == null || path.charAt( 0 ) != '/' )
{
res.sendError( HttpServletResponse.SC_BAD_REQUEST );
return;
}
if ( path.indexOf( "/../" ) != -1 || path.endsWith( "/.." ) )
{
res.sendError( HttpServletResponse.SC_FORBIDDEN );
return;
}
// Make a version without the leading /.
String pathname = path.substring( 1 );
if ( pathname.length() == 0 )
pathname = "./";
dispatchPathname( req, res, headOnly, path, pathname );
}
private void dispatchPathname( HttpServletRequest req, HttpServletResponse res, boolean headOnly, String path, String pathname ) throws IOException
{
String filename = pathname.replace( '/', File.separatorChar );
if ( filename.charAt( filename.length() - 1 ) == File.separatorChar )
filename = filename.substring( 0, filename.length() - 1 );
filename = getServletContext().getRealPath( filename );
File file = new File( filename );
if ( file.exists() )
{
if ( ! file.isDirectory() )
serveFile( req, res, headOnly, path, filename, file );
else
{
if ( pathname.charAt( pathname.length() - 1 ) != '/' )
redirectDirectory( req, res, path, file );
else
{
String indexFilename =
filename + File.separatorChar + "index.html";
File indexFile = new File( indexFilename );
if ( indexFile.exists() )
serveFile(
req, res, headOnly, path, indexFilename,
indexFile );
else
serveDirectory(
req, res, headOnly, path, filename, file );
}
}
}
else
{
if ( pathname.endsWith( "/index.html" ) )
dispatchPathname(
req, res, headOnly, path,
pathname.substring( 0, pathname.length() - 10 ) );
else if ( pathname.equals( "index.html" ) )
dispatchPathname( req, res, headOnly, path, "./" );
else
res.sendError( HttpServletResponse.SC_NOT_FOUND );
}
}
protected void serveFile( HttpServletRequest req, HttpServletResponse res, boolean headOnly, String path, String filename, File file ) throws IOException
{
// log( "getting " + path );
if ( ! file.canRead() )
{
res.sendError( HttpServletResponse.SC_FORBIDDEN );
return;
}
// Handle If-Modified-Since.
res.setStatus( HttpServletResponse.SC_OK );
long lastMod = file.lastModified();
String ifModSinceStr = req.getHeader( "If-Modified-Since" );
long ifModSince = -1;
if ( ifModSinceStr != null )
{
int semi = ifModSinceStr.indexOf( ';' );
if ( semi != -1 )
ifModSinceStr = ifModSinceStr.substring( 0, semi );
try
{
ifModSince =
DateFormat.getDateInstance().parse( ifModSinceStr ).getTime();
}
catch ( Exception ignore ) {}
}
if ( ifModSince != -1 && ifModSince >= lastMod )
{
res.setStatus( HttpServletResponse.SC_NOT_MODIFIED );
headOnly = true;
}
String rangeStr = req.getHeader( "Range" );
if ( rangeStr != null )
{
//!!!
}
res.setContentType( getServletContext().getMimeType( filename ) );
res.setContentLength( (int) file.length() );
res.setDateHeader( "Last-modified", lastMod );
OutputStream out = res.getOutputStream();
if ( ! headOnly )
{
// Check throttle.
if ( throttleTab != null )
{
ThrottleItem throttleItem =
(ThrottleItem) throttleTab.get( path );
if ( throttleItem != null )
{
// !!! Need to account for multiple simultaneous fetches.
out = new ThrottledOutputStream(
out, throttleItem.getMaxBps() );
}
}
InputStream in = new FileInputStream( file );
copyStream( in, out );
in.close();
}
out.close();
}
/// Copy a file from in to out.
// Sub-classes can override this in order to do filtering of some sort.
public void copyStream( InputStream in, OutputStream out ) throws IOException
{
Acme.Utils.copyStream( in, out );
}
private void serveDirectory( HttpServletRequest req, HttpServletResponse res, boolean headOnly, String path, String filename, File file ) throws IOException
{
log( "indexing " + path );
if ( ! file.canRead() )
{
res.sendError( HttpServletResponse.SC_FORBIDDEN );
return;
}
res.setStatus( HttpServletResponse.SC_OK );
res.setContentType( "text/html" );
OutputStream out = res.getOutputStream();
if ( ! headOnly )
{
PrintStream p = new PrintStream( new BufferedOutputStream( out ) );
p.println( "<HTML><HEAD>" );
p.println( "<TITLE>Index of " + path + "</TITLE>" );
p.println( "</HEAD><BODY BGCOLOR=\"#ffffff\">" );
p.println( "<H2>Index of " + path + "</H2>" );
p.println( "<PRE>" );
p.println( "mode bytes last-changed name" );
p.println( "<HR>" );
String[] names = file.list();
Acme.Utils.sortStrings( names );
for ( int i = 0; i < names.length; ++i )
{
String aFilename = filename + File.separatorChar + names[i];
File aFile = new File( aFilename );
String aFileType;
if ( aFile.isDirectory() )
aFileType = "d";
else if ( aFile.isFile() )
aFileType = "-";
else
aFileType = "?";
String aFileRead = ( aFile.canRead() ? "r" : "-" );
String aFileWrite = ( aFile.canWrite() ? "w" : "-" );
String aFileExe = "-";
String aFileSize = Acme.Fmt.fmt( aFile.length(), 8 );
String aFileDate =
Acme.Utils.lsDateStr( new Date( aFile.lastModified() ) );
String aFileDirsuf = ( aFile.isDirectory() ? "/" : "" );
String aFileSuf = ( aFile.isDirectory() ? "/" : "" );
p.println(
aFileType + aFileRead + aFileWrite + aFileExe +
" " + aFileSize + " " + aFileDate + " " +
"<A HREF=\"" + names[i] + aFileDirsuf + "\">" +
names[i] + aFileSuf + "</A>" );
}
p.println( "</PRE>" );
p.println( "<HR>" );
ServeUtils.writeAddress( p );
p.println( "</BODY></HTML>" );
p.flush();
}
out.close();
}
protected void redirectDirectory( HttpServletRequest req, HttpServletResponse res, String path, File file ) throws IOException
{
log( "redirecting " + path );
res.sendRedirect( path + "/" );
}
}