httpmessages.java

Tomcat 4.1与WebServer集成组件的源代码包.

/*
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */ 

package org.apache.tomcat.util.http;

import org.apache.tomcat.util.res.StringManager;

import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;

/**
 * Handle (internationalized) HTTP messages.
 * 
 * @author James Duncan Davidson [[e-mail]]
 * @author James Todd [[e-mail]]
 * @author Jason Hunter [[e-mail]]
 * @author Harish Prabandham
 * @author [e-mail]
 */
public class HttpMessages {
    // XXX move message resources in this package
    protected static StringManager sm =
        StringManager.getManager("org.apache.tomcat.util.http.res");
	
    static String st_200=null;
    static String st_302=null;
    static String st_400=null;
    static String st_404=null;
    
    /** Get the status string associated with a status code.
     *  No I18N - return the messages defined in the HTTP spec.
     *  ( the user isn't supposed to see them, this is the last
     *  thing to translate)
     *
     *  Common messages are cached.
     *
     */
    public static String getMessage( int status ) {
	// method from Response.
	
	// Does HTTP requires/allow international messages or
	// are pre-defined? The user doesn't see them most of the time
	switch( status ) {
	case 200:
	    if( st_200==null ) st_200=sm.getString( "sc.200");
	    return st_200;
	case 302:
	    if( st_302==null ) st_302=sm.getString( "sc.302");
	    return st_302;
	case 400:
	    if( st_400==null ) st_400=sm.getString( "sc.400");
	    return st_400;
	case 404:
	    if( st_404==null ) st_404=sm.getString( "sc.404");
	    return st_404;
	}
	return sm.getString("sc."+ status);
    }

    /**
     * Filter the specified message string for characters that are sensitive
     * in HTML.  This avoids potential attacks caused by including JavaScript
     * codes in the request URL that is often reported in error messages.
     *
     * @param message The message string to be filtered
     */
    public static String filter(String message) {

	if (message == null)
	    return (null);

	char content[] = new char[message.length()];
	message.getChars(0, message.length(), content, 0);
	StringBuffer result = new StringBuffer(content.length + 50);
	for (int i = 0; i < content.length; i++) {
	    switch (content[i]) {
	    case '<':
		result.append("&lt;");
		break;
	    case '>':
		result.append("&gt;");
		break;
	    case '&':
		result.append("&amp;");
		break;
	    case '"':
		result.append("&quot;");
		break;
	    default:
		result.append(content[i]);
	    }
	}
	return (result.toString());
    }

}