basicattachmentprovider.java

wiki建站资源 java编写的 很好用

/* 
    JSPWiki - a JSP-based WikiWiki clone.

    Copyright (C) 2001-2002 Janne Jalkanen ([e-mail])

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 2.1 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package com.ecyrd.jspwiki.providers;

import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.io.File;
import java.io.FilenameFilter;
import java.io.FileOutputStream;
import java.io.FileInputStream;

import java.util.Collection;
import java.util.Properties;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Date;
import java.util.List;
import java.util.Collections;

import org.apache.log4j.Logger;

import com.ecyrd.jspwiki.*;
import com.ecyrd.jspwiki.attachment.Attachment;

/**
 *  Provides basic, versioning attachments.
 *
 *  <PRE>
 *   Structure is as follows:
 *      attachment_dir/
 *         ThisPage/
 *            attachment.doc/
 *               attachment.properties
 *               1.doc
 *               2.doc
 *               3.doc
 *            picture.png/
 *               attachment.properties
 *               1.png
 *               2.png
 *         ThatPage/
 *            picture.png/
 *               attachment.properties
 *               1.png
 *             
 *  </PRE>
 *
 *  The names of the directories will be URLencoded.
 *  <p>
 *  "attachment.properties" consists of the following items:
 *  <UL>
 *   <LI>1.author = author name for version 1 (etc)
 *  </UL>
 */
public class BasicAttachmentProvider
    implements WikiAttachmentProvider
{
    private String m_storageDir;
    public static final String PROP_STORAGEDIR = "jspwiki.basicAttachmentProvider.storageDir";

    public static final String PROPERTY_FILE   = "attachment.properties";

    public static final String DIR_EXTENSION   = "-att";
    public static final String ATTDIR_EXTENSION = "-dir";
    
    static final Logger log = Logger.getLogger( BasicAttachmentProvider.class );

    public void initialize( WikiEngine engine, Properties properties ) 
        throws NoRequiredPropertyException,
               IOException
    {
        m_storageDir = WikiEngine.getRequiredProperty( properties, PROP_STORAGEDIR );

        //
        //  Check if the directory exists - if it doesn't, create it.
        //
        File f = new File( m_storageDir );

        if( !f.exists() )
        {
            f.mkdirs();
        }
    }

    /**
     *  Finds storage dir, and if it exists, makes sure that it is valid.
     *
     *  @param wikipage Page to which this attachment is attached.
     */
    private File findPageDir( String wikipage )
        throws ProviderException
    {
        wikipage = mangleName( wikipage );

        File f = new File( m_storageDir, wikipage+DIR_EXTENSION );

        if( f.exists() && !f.isDirectory() )
        {
            throw new ProviderException("Storage dir '"+f.getAbsolutePath()+"' is not a directory!");
        }

        return f;
    }

    private static String mangleName( String wikiname )
    {
        String res = TextUtil.urlEncodeUTF8( wikiname );

        return res;
    }

    private static String unmangleName( String filename )
    {
        return TextUtil.urlDecodeUTF8( filename );
    }
    
    /**
     *  Finds the dir in which the attachment lives.
     */
    private File findAttachmentDir( Attachment att )
        throws ProviderException
    {
        File f = new File( findPageDir(att.getParentName()), 
                           mangleName(att.getFileName()+ATTDIR_EXTENSION) );

        //
        //  Migration code for earlier versions of JSPWiki.
        //  Originally, we used plain filename.  Then we realized we need
        //  to urlencode it.  Then we realized that we have to use a
        //  postfix to make sure illegal file names are never formed.
        //
        if( !f.exists() )
        {
            File oldf = new File( findPageDir( att.getParentName() ),
                                  mangleName( att.getFileName() ) );
            if( oldf.exists() )
            {
                f = oldf;
            }
            else
            {
                oldf = new File( findPageDir( att.getParentName() ),
                                 att.getFileName() );

                if( oldf.exists() )
                {
                    f = oldf;
                }
            }
        }

        return f;
    }

    /**
     *  Goes through the repository and decides which version is
     *  the newest one in that directory.
     *
     *  @return Latest version number in the repository, or 0, if
     *          there is no page in the repository.
     */
    private int findLatestVersion( Attachment att )
        throws ProviderException
    {
        // File pageDir = findPageDir( att.getName() );
        File attDir  = findAttachmentDir( att );

        // log.debug("Finding pages in "+attDir.getAbsolutePath());
        String[] pages = attDir.list( new AttachmentVersionFilter() );

        if( pages == null )
        {
            return 0; // No such thing found.
        }

        int version = 0;

        for( int i = 0; i < pages.length; i++ )
        {
            // log.debug("Checking: "+pages[i]);
            int cutpoint = pages[i].indexOf( '.' );
                String pageNum = ( cutpoint > 0 ) ? pages[i].substring( 0, cutpoint ) : pages[i] ;

                try
                {
                    int res = Integer.parseInt( pageNum );

                    if( res > version )
                    {
                        version = res;
                    }
                }
                catch( NumberFormatException e ) {} // It's okay to skip these.
            }

        return version;
    }

    /**
     *  Returns the file extension.  For example "test.png" returns "png".
     *  <p>
     *  If file has no extension, will return "bin"
     */
    protected static String getFileExtension( String filename )
    {
        String fileExt = "bin";

        int dot = filename.lastIndexOf('.');
        if( dot >= 0 && dot < filename.length()-1 )
        {
            fileExt = mangleName( filename.substring( dot+1 ) );
        }

        return fileExt;
    }

    /**
     *  Writes the page properties back to the file system.
     *  Note that it WILL overwrite any previous properties.
     */
    private void putPageProperties( Attachment att, Properties properties )
        throws IOException,
               ProviderException
    {
        File attDir = findAttachmentDir( att );
        File propertyFile = new File( attDir, PROPERTY_FILE );

        OutputStream out = new FileOutputStream( propertyFile );

        properties.store( out, 
                          " JSPWiki page properties for "+
                          att.getName()+
                          ". DO NOT MODIFY!" );

        out.close();
    }

    /**
     *  Reads page properties from the file system.
     */
    private Properties getPageProperties( Attachment att )
        throws IOException,
               ProviderException
    {
        Properties props = new Properties();

        File propertyFile = new File( findAttachmentDir(att), PROPERTY_FILE );

        if( propertyFile != null && propertyFile.exists() )
        {
            InputStream in = new FileInputStream( propertyFile );

            props.load(in);

            in.close();
        }
        
        return props;
    }

    public void putAttachmentData( Attachment att, InputStream data )
        throws ProviderException,
               IOException
    {
        OutputStream out = null;
        File attDir = findAttachmentDir( att );

        if(!attDir.exists())
        {
            attDir.mkdirs();
        }

        int latestVersion = findLatestVersion( att );

        // System.out.println("Latest version is "+latestVersion);

        try
        {
            int versionNumber = latestVersion+1;

            File newfile = new File( attDir, versionNumber+"."+
                                     getFileExtension(att.getFileName()) );

            log.info("Uploading attachment "+att.getFileName()+" to page "+att.getParentName());
            log.info("Saving attachment contents to "+newfile.getAbsolutePath());
            out = new FileOutputStream(newfile);

            FileUtil.copyContents( data, out );