welcomefilter.java

来自「是离开的肌肤了卡机是离开的就富利卡及是了的开发及拉考试及的福利科技阿斯利康的肌肤」· Java 代码 · 共 67 行

// ========================================================================
// Copyright 199-2004 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.servlet;
import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

/* ------------------------------------------------------------ */
/** Welcome Filter
 * This filter can be used to server an index file for a directory 
 * when no index file actually exists (thus the web.xml mechanism does
 * not work).
 * 
 * This filter will dispatch requests to a directory (URLs ending with /)
 * to the welcome URL determined by the "welcome" init parameter.  So if
 * the filter "welcome" init parameter is set to "index.do" then a request
 * to "/some/directory/" will be dispatched to "/some/directory/index.do" and
 * will be handled by any servlets mapped to that URL.
 *
 * Requests to "/some/directory" will be redirected to "/some/directory/".
 */
public  class WelcomeFilter implements Filter
{
    private String welcome;
    
    public void init(FilterConfig filterConfig)
    {
        welcome=filterConfig.getInitParameter("welcome");
	if (welcome==null)
	    welcome="index.html";
    }

    /* ------------------------------------------------------------ */
    public void doFilter(ServletRequest request,
                         ServletResponse response,
                         FilterChain chain)
	throws IOException, ServletException
    {
        String path=((HttpServletRequest)request).getServletPath();
        if (welcome!=null && path.endsWith("/"))
            request.getRequestDispatcher(path+welcome).forward(request,response);
        else
            chain.doFilter(request, response);
    }

    public void destroy() {}
}