home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Tomcat example source code file (HttpUtils.java)

This example Tomcat source code file (HttpUtils.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

hashtable, hashtable, httputils, illegalargumentexception, illegalargumentexception, io, ioexception, lstring_file, servlet, servletinputstream, string, string, stringbuffer, stringbuffer, stringindexoutofboundsexception, stringtokenizer, util

The Tomcat HttpUtils.java source code

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 javax.servlet.http;

import javax.servlet.ServletInputStream;
import java.util.Hashtable;
import java.util.ResourceBundle;
import java.util.StringTokenizer;
import java.io.IOException;

/**
 * @deprecated		As of Java(tm) Servlet API 2.3. 
 *			These methods were only useful
 *			with the default encoding and have been moved
 *			to the request interfaces.
 *
*/


public class HttpUtils {

    private static final String LSTRING_FILE =
	"javax.servlet.http.LocalStrings";
    private static ResourceBundle lStrings =
	ResourceBundle.getBundle(LSTRING_FILE);
        
    
    
    /**
     * Constructs an empty <code>HttpUtils object.
     *
     */

    public HttpUtils() {}
    
    
    
    

    /**
     *
     * Parses a query string passed from the client to the
     * server and builds a <code>HashTable object
     * with key-value pairs. 
     * The query string should be in the form of a string
     * packaged by the GET or POST method, that is, it
     * should have key-value pairs in the form <i>key=value,
     * with each pair separated from the next by a & character.
     *
     * <p>A key can appear more than once in the query string
     * with different values. However, the key appears only once in 
     * the hashtable, with its value being
     * an array of strings containing the multiple values sent
     * by the query string.
     * 
     * <p>The keys and values in the hashtable are stored in their
     * decoded form, so
     * any + characters are converted to spaces, and characters
     * sent in hexadecimal notation (like <i>%xx) are
     * converted to ASCII characters.
     *
     * @param s		a string containing the query to be parsed
     *
     * @return		a <code>HashTable object built
     * 			from the parsed key-value pairs
     *
     * @exception IllegalArgumentException	if the query string 
     *						is invalid
     *
     */

    static public Hashtable parseQueryString(String s) {

	String valArray[] = null;
	
	if (s == null) {
	    throw new IllegalArgumentException();
	}
	Hashtable ht = new Hashtable();
	StringBuffer sb = new StringBuffer();
	StringTokenizer st = new StringTokenizer(s, "&");
	while (st.hasMoreTokens()) {
	    String pair = (String)st.nextToken();
	    int pos = pair.indexOf('=');
	    if (pos == -1) {
		// XXX
		// should give more detail about the illegal argument
		throw new IllegalArgumentException();
	    }
	    String key = parseName(pair.substring(0, pos), sb);
	    String val = parseName(pair.substring(pos+1, pair.length()), sb);
	    if (ht.containsKey(key)) {
		String oldVals[] = (String []) ht.get(key);
		valArray = new String[oldVals.length + 1];
		for (int i = 0; i < oldVals.length; i++) 
		    valArray[i] = oldVals[i];
		valArray[oldVals.length] = val;
	    } else {
		valArray = new String[1];
		valArray[0] = val;
	    }
	    ht.put(key, valArray);
	}
	return ht;
    }




    /**
     *
     * Parses data from an HTML form that the client sends to 
     * the server using the HTTP POST method and the 
     * <i>application/x-www-form-urlencoded MIME type.
     *
     * <p>The data sent by the POST method contains key-value
     * pairs. A key can appear more than once in the POST data
     * with different values. However, the key appears only once in 
     * the hashtable, with its value being
     * an array of strings containing the multiple values sent
     * by the POST method.
     *
     * <p>The keys and values in the hashtable are stored in their
     * decoded form, so
     * any + characters are converted to spaces, and characters
     * sent in hexadecimal notation (like <i>%xx) are
     * converted to ASCII characters.
     *
     *
     *
     * @param len	an integer specifying the length,
     *			in characters, of the 
     *			<code>ServletInputStream
     *			object that is also passed to this
     *			method
     *
     * @param in	the <code>ServletInputStream
     *			object that contains the data sent
     *			from the client
     * 
     * @return		a <code>HashTable object built
     *			from the parsed key-value pairs
     *
     *
     * @exception IllegalArgumentException	if the data
     *			sent by the POST method is invalid
     *
     */
     

    static public Hashtable parsePostData(int len, 
					  ServletInputStream in)
    {
	// XXX
	// should a length of 0 be an IllegalArgumentException
	
	if (len <=0)
	    return new Hashtable(); // cheap hack to return an empty hash

	if (in == null) {
	    throw new IllegalArgumentException();
	}
	
	//
	// Make sure we read the entire POSTed body.
	//
        byte[] postedBytes = new byte [len];
        try {
            int offset = 0;
       
	    do {
		int inputLen = in.read (postedBytes, offset, len - offset);
		if (inputLen <= 0) {
		    String msg = lStrings.getString("err.io.short_read");
		    throw new IllegalArgumentException (msg);
		}
		offset += inputLen;
	    } while ((len - offset) > 0);

	} catch (IOException e) {
	    throw new IllegalArgumentException(e.getMessage());
	}

        // XXX we shouldn't assume that the only kind of POST body
        // is FORM data encoded using ASCII or ISO Latin/1 ... or
        // that the body should always be treated as FORM data.
        //

        try {
            String postedBody = new String(postedBytes, 0, len, "8859_1");
            return parseQueryString(postedBody);
        } catch (java.io.UnsupportedEncodingException e) {
            // XXX function should accept an encoding parameter & throw this
            // exception.  Otherwise throw something expected.
            throw new IllegalArgumentException(e.getMessage());
        }
    }




    /*
     * Parse a name in the query string.
     */

    static private String parseName(String s, StringBuffer sb) {
	sb.setLength(0);
	for (int i = 0; i < s.length(); i++) {
	    char c = s.charAt(i); 
	    switch (c) {
	    case '+':
		sb.append(' ');
		break;
	    case '%':
		try {
		    sb.append((char) Integer.parseInt(s.substring(i+1, i+3), 
						      16));
		    i += 2;
		} catch (NumberFormatException e) {
		    // XXX
		    // need to be more specific about illegal arg
		    throw new IllegalArgumentException();
		} catch (StringIndexOutOfBoundsException e) {
		    String rest  = s.substring(i);
		    sb.append(rest);
		    if (rest.length()==2)
			i++;
		}
		
		break;
	    default:
		sb.append(c);
		break;
	    }
	}
	return sb.toString();
    }




    /**
     *
     * Reconstructs the URL the client used to make the request,
     * using information in the <code>HttpServletRequest object.
     * The returned URL contains a protocol, server name, port
     * number, and server path, but it does not include query
     * string parameters.
     * 
     * <p>Because this method returns a StringBuffer,
     * not a string, you can modify the URL easily, for example,
     * to append query parameters.
     *
     * <p>This method is useful for creating redirect messages
     * and for reporting errors.
     *
     * @param req	a <code>HttpServletRequest object
     *			containing the client's request
     * 
     * @return		a <code>StringBuffer object containing
     *			the reconstructed URL
     *
     */

    public static StringBuffer getRequestURL (HttpServletRequest req) {
	StringBuffer url = new StringBuffer ();
	String scheme = req.getScheme ();
	int port = req.getServerPort ();
	String urlPath = req.getRequestURI();
	
	//String		servletPath = req.getServletPath ();
	//String		pathInfo = req.getPathInfo ();

	url.append (scheme);		// http, https
	url.append ("://");
	url.append (req.getServerName ());
	if ((scheme.equals ("http") && port != 80)
		|| (scheme.equals ("https") && port != 443)) {
	    url.append (':');
	    url.append (req.getServerPort ());
	}
	//if (servletPath != null)
	//    url.append (servletPath);
	//if (pathInfo != null)
	//    url.append (pathInfo);
	url.append(urlPath);
	return url;
    }
}



Other Tomcat examples (source code examples)

Here is a short list of links related to this Tomcat HttpUtils.java source code file:



my book on functional programming

 

new blog posts

 

Copyright 1998-2019 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.