rpcservlet.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.xmlrpc;

import java.io.*;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
import org.apache.xmlrpc.XmlRpcServer;

import com.ecyrd.jspwiki.*;

/**
 *  Handles all incoming servlet requests for XML-RPC calls.
 *  <P>
 *  Uses two initialization parameters:
 *  <UL>
 *  <LI><B>handler</B> : the class which is used to handle the RPC calls.
 *  <LI><B>prefix</B> : The command prefix for that particular handler.
 *  </UL>
 *  
 *  @author Janne Jalkanen
 *  @since 1.6.6
 */
public class RPCServlet extends HttpServlet
{
    /** This is what is appended to each command, if the handler has
        not been specified.  */
    // FIXME: Should this be $default?
    public static final String XMLRPC_PREFIX = "wiki";

    private WikiEngine       m_engine;
    private XmlRpcServer     m_xmlrpcServer = new XmlRpcServer();

    Logger log = Logger.getLogger( RPCServlet.class ); 

    public void initHandler( String prefix, String handlerName )
        throws ClassNotFoundException,
               InstantiationException,
               IllegalAccessException
    {
        Class handlerClass = Class.forName( handlerName );
        WikiRPCHandler rpchandler = (WikiRPCHandler) handlerClass.newInstance();
        rpchandler.initialize( m_engine );
        m_xmlrpcServer.addHandler( prefix, rpchandler );
    }

    /**
     *  Initializes the servlet.
     */
    public void init( ServletConfig config )
        throws ServletException
    {
        m_engine = WikiEngine.getInstance( config );

        String handlerName = config.getInitParameter( "handler" );
        String prefix      = config.getInitParameter( "prefix" );

        if( handlerName == null ) handlerName = "com.ecyrd.jspwiki.xmlrpc.RPCHandler";
        if( prefix == null )      prefix = XMLRPC_PREFIX;

        try
        {
            initHandler( prefix, handlerName );

            //
            // FIXME: The metaweblog API should be possible to turn off.
            //
            initHandler( "metaWeblog", 
                         "com.ecyrd.jspwiki.xmlrpc.MetaWeblogHandler" );
        }
        catch( Exception e )
        {
            log.fatal("Unable to start RPC interface: ", e);
            throw new ServletException( "No RPC interface", e );
        }
    }

    /**
     *  Handle HTTP POST.  This is an XML-RPC call, and we'll just forward
     *  the query to an XmlRpcServer.
     */
    public void doPost( HttpServletRequest request, HttpServletResponse response )
        throws ServletException
    {
        log.debug("Received POST to RPCServlet");

        try
        {
            byte[] result = m_xmlrpcServer.execute( request.getInputStream() );

            //
            //  I think it's safe to write the output as UTF-8:
            //  The XML-RPC standard never creates other than USASCII
            //  (which is UTF-8 compatible), and our special UTF-8
            //  hack just creates UTF-8.  So in all cases our butt
            //  should be covered.
            //
            response.setContentType( "text/xml; charset=utf-8" );
            response.setContentLength( result.length );

            OutputStream out = response.getOutputStream();
            out.write( result );
            out.flush();

            // log.debug("Result = "+new String(result) );
        }
        catch( IOException e )
        {
            throw new ServletException("Failed to build RPC result", e);
        }
    }

    /**
     *  Handles HTTP GET.  However, we do not respond to GET requests,
     *  other than to show an explanatory text.
     */
    public void doGet( HttpServletRequest request, HttpServletResponse response )
        throws ServletException
    {
        log.debug("Received HTTP GET to RPCServlet");

        try
        {
            String msg = "We do not support HTTP GET here.  Sorry.";
            response.setContentType( "text/plain" );
            response.setContentLength( msg.length() );
        
            PrintWriter writer = new PrintWriter( new OutputStreamWriter( response.getOutputStream() ) );

            writer.println( msg );
            writer.flush();
        }
        catch( IOException e )
        {
            throw new ServletException("Failed to build RPC result", e);
        }
    }

}