attachmentservlet.java

wiki建站资源 java编写的 很好用

                if( in != null ) in.close();
                if( out != null ) out.close();
            }
        }
    }




    /**
     * Grabs mime/multipart data and stores it into the temporary area.
     * Uses other parameters to determine which name to store as.
     *
     * <p>The input to this servlet is generated by an HTML FORM with
     * two parts. The first, named 'page', is the WikiName identifier
     * for the parent file. The second, named 'content', is the binary
     * content of the file.
     */
    public void doPost( HttpServletRequest  req, HttpServletResponse res ) 
        throws IOException, ServletException 
    {
        try
        {
            String nextPage = upload( req );
            req.getSession().removeAttribute("msg");
            res.sendRedirect( nextPage );
        }
        catch( RedirectException e )
        {
            req.getSession().setAttribute("msg", e.getMessage());
            res.sendRedirect( e.getRedirect() );
        }
    }


    /**
     *  Uploads a specific mime multipart input set, intercepts exceptions.
     *
     *  @return The page to which we should go next.
     */
    protected String upload( HttpServletRequest req )
        throws RedirectException,
               IOException
    {
        String msg     = "";
        String attName = "(unknown)";
        String errorPage = m_engine.getURL( WikiContext.ERROR, "", null, false ); // If something bad happened, Upload should be able to take care of most stuff
        String nextPage = errorPage;

        try
        {
            MultipartRequest multi;

            multi = new MultipartRequest( null, // no debugging
                                          req.getContentType(), 
                                          req.getContentLength(), 
                                          req.getInputStream(), 
                                          m_tmpDir, 
                                          Integer.MAX_VALUE,
                                          m_engine.getContentEncoding() );

            nextPage        = multi.getURLParameter( "nextpage" );
            String wikipage = multi.getURLParameter( "page" );

            WikiContext context = m_engine.createContext( req, WikiContext.UPLOAD );
            errorPage = context.getURL( WikiContext.UPLOAD,
                                        wikipage );

            //
            //  FIXME: This has the unfortunate side effect that it will receive the
            //  contents.  But we can't figure out the page to redirect to
            //  before we receive the file, due to the stupid constructor of MultipartRequest.
            //
            if( req.getContentLength() > m_maxSize )
            {
                // FIXME: Does not delete the received files.
                throw new RedirectException( "File exceeds maximum size ("+m_maxSize+" bytes)",
                                             errorPage );
            }

            UserProfile user    = context.getCurrentUser();

            //
            //  Go through all files being uploaded.
            //
            Enumeration files = multi.getFileParameterNames();

            while( files.hasMoreElements() )
            {
                String part = (String) files.nextElement();
                File   f    = multi.getFile( part );
                AttachmentManager mgr = m_engine.getAttachmentManager();
                InputStream in;

                try
                {
                    //
                    //  Is a file to be uploaded.
                    //

                    String filename = multi.getFileSystemName( part );

                    if( filename == null || filename.trim().length() == 0 )
                    {
                        log.error("Empty file name given.");

                        throw new RedirectException("Empty file name given.",
                                                    errorPage);
                    }

                    //
                    //  Should help with IE 5.22 on OSX
                    //
                    filename = filename.trim();

                    //
                    //  Remove any characters that might be a problem. Most
                    //  importantly - characters that might stop processing
                    //  of the URL.
                    //
                    filename = StringUtils.replaceChars( filename, "#?\"'", "____" );
                    
                    log.debug("file="+filename);
                    //
                    //  Attempt to open the input stream
                    //
                    if( f != null )
                    {
                        in = new FileInputStream( f );
                    }
                    else
                    {
                        //
                        //  This happens onl when the size of the 
                        //  file is small enough to be cached in memory
                        //
                        in = multi.getFileContents( part );
                    }

                    if( in == null )
                    {
                        log.error("File could not be opened.");

                        throw new RedirectException("File could not be opened.",
                                                    errorPage);
                    }

                    //
                    //  Check whether we already have this kind of a page.
                    //  If the "page" parameter already defines an attachment
                    //  name for an update, then we just use that file.
                    //  Otherwise we create a new attachment, and use the
                    //  filename given.  Incidentally, this will also mean
                    //  that if the user uploads a file with the exact
                    //  same name than some other previous attachment,
                    //  then that attachment gains a new version.
                    //

                    Attachment att = mgr.getAttachmentInfo( wikipage );

                    if( att == null )
                    {
                        att = new Attachment( wikipage, filename );
                    }

                    if( !m_engine.pageExists(att.getParentName()) )
                    {
                        throw new RedirectException("Parent page does not exist.",
                                                    errorPage );
                    }
                    
                    //
                    //  Check if we're allowed to do this?
                    //

                    if( m_engine.getAuthorizationManager().checkPermission( att,
                                                                            user,
                                                                            "upload" ) )
                    {
                        if( user != null )
                        {
                            att.setAuthor( user.getName() );
                        }
                
                        m_engine.getAttachmentManager().storeAttachment( att, in );

                        log.info( "User " + user + " uploaded attachment to " + wikipage + 
                                  " called "+filename+", size " + multi.getFileSize(part) );
                    }
                    else
                    {
                        throw new RedirectException("No permission to upload a file",
                                                    errorPage);
                    }
                }
                finally
                {
                    if( f != null )
                        f.delete();
                }
            }

            // Inform the JSP page of which file we are handling:
            // req.setAttribute( ATTR_ATTACHMENT, wikiname );
        }
        catch( ProviderException e )
        {
            msg = "Upload failed because the provider failed: "+e.getMessage();
            log.warn( msg + " (attachment: " + attName + ")", e );

            throw new IOException(msg);
        }
        catch( IOException e )
        {
            // Show the submit page again, but with a bit more 
            // intimidating output.
            msg = "Upload failure: " + e.getMessage();
            log.warn( msg + " (attachment: " + attName + ")", e );

            throw e;
        }
        finally
        {
            // FIXME: In case of exceptions should absolutely
            //        remove the uploaded file.
        }

        return nextPage;
    }


    /**
     * Produces debug output listing parameters and files.
     */
    /*
    private void debugContentList( MultipartRequest  multi )
    {
        StringBuffer sb = new StringBuffer();
        
        sb.append( "Upload information: parameters: [" );

        Enumeration params = multi.getParameterNames();
        while( params.hasMoreElements() ) 
        {
            String name = (String)params.nextElement();
            String value = multi.getURLParameter( name );
            sb.append( "[" + name + " = " + value + "]" );
        }
              
        sb.append( " files: [" );
        Enumeration files = multi.getFileParameterNames();
        while( files.hasMoreElements() ) 
        {
            String name = (String)files.nextElement();
            String filename = multi.getFileSystemName( name );
            String type = multi.getContentType( name );
            File f = multi.getFile( name );
            sb.append( "[name: " + name );
            sb.append( " temp_file: " + filename );
            sb.append( " type: " + type );
            if (f != null) 
            {
                sb.append( " abs: " + f.getPath() );
                sb.append( " size: " + f.length() );
            }
            sb.append( "]" );
        }
        sb.append( "]" );


        log.debug( sb.toString() );
    }
    */

}