urlhelper.java

来自「jakarta-taglibs」· Java 代码 · 共 65 行

/*
 * Copyright 1999,2004 The Apache Software Foundation.
 * 
 * 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.apache.taglibs.io;

import java.net.MalformedURLException;
import java.net.URL;

import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.PageContext;

/** Some helper methods for creating URLs that can handle relative or absolute
  * URIs or full URLs.
  * 
  * @author <a href="mailto:[e-mail]">James Strachan</a>
  * @version $Revision: 1.3 $
  */
public class URLHelper {

    public static URL createURL(String uri, PageContext pageContext) throws MalformedURLException {
        ServletContext context = pageContext.getServletContext();
        ServletRequest request = pageContext.getRequest();
        if ( request instanceof HttpServletRequest ) {
            return createURL( uri, (HttpServletRequest) request, context );
        }
        else if ( uri.startsWith( "/" ) ) {
            int port = request.getServerPort();
            String host = request.getServerName();
            String protocol = "http";
            return new URL( protocol, host, port, uri );
        }
        else {
            return new URL(uri);
        }
    }
    
    public static URL createURL(String uri, HttpServletRequest request, ServletContext context) throws MalformedURLException {
        if ( uri.startsWith( "/" ) ) {
            int port = request.getServerPort();
            String host = request.getServerName();
            String protocol = "http";
            String path = request.getContextPath() + uri;
            return new URL( protocol, host, port, path );
        }
        else {
            return new URL( uri );
        }
    }
}