Sometimes, we need to put some url as a parameter in the page url, example:
https://open.login.yahoo.com/openid/yrp/signin?returnUrl=http%3A%2F%2Fmail.yahoo.com&rpcrumb=TzwDznuzRzH&.src=ym
The value of parameter "returnUrl" is an encoded url (http%3A%2F%2Fmail.yahoo.com)
So, whenever you want to put a URL as a parameter, you have to URL encode it.
(you can use JS function encodeUrlComponenet
Showing posts with label url-encoding. Show all posts
Showing posts with label url-encoding. Show all posts
30 January 2012
07 May 2010
Enable Arabic (non-ASCII) characters in request parameteres of "GET" method
Al salamo Alykom,
If you have a JSP page that sends a request with non-ASCII data to a Servlet, here's the steps to enable the Servlet from interrupting the correct character.
First, for your Servlet (Server) to interrupt the character encoding correctly, It needs to know in what encoding the client will send the request.
1- suppose you are sending the following JSP Page:
2- create the following Class:
3- create that filter :
and here's its mapping:
4- and here's the Servlet that accepts the User input:
Good luck :)
(for more comprehensive tutorial, please see http://www.arabteam2000-forum.com/index.php?showtopic=220589 (In Arabic) )
If you have a JSP page that sends a request with non-ASCII data to a Servlet, here's the steps to enable the Servlet from interrupting the correct character.
First, for your Servlet (Server) to interrupt the character encoding correctly, It needs to know in what encoding the client will send the request.
1- suppose you are sending the following JSP Page:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="SomeServlet" method="get">
Enter your name (in arabic, or in any non-ASCII language)<input type="text" name="username" />
<input type="submit">
</form>
</body>
</html>
2- create the following Class:
package com.forat.web.util;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
/**
* Used to overrides the implementations of
* getParameterXXXXX methods in {@link HttpServletRequest} <br />
* It decoded the query string for the incoming requests Requests before calling the getParameterXXXX methods
*
* @author mhewedy
*/
public class EncodedHttpServletRequest extends HttpServletRequestWrapper {
private String encoding;
private HttpServletRequest request;
private Map paramMap;
/**
* This Constructor is the same as if you create an instance by calling
* EncodedHttpServletRequest(request, "GB2312")
* @param request
* @see #EncodedHttpServletRequest(HttpServletRequest, String)
*/
public EncodedHttpServletRequest(HttpServletRequest request) {
this(request, "UTF-8");
}
/**
* Create instance of this class, trying to set the character encoding - that will be used to decode the query
* string - by calling {@link HttpServletRequest#getCharacterEncoding()}, if its value is null,
* then the <em>encoding</em> parameter's value will be used instead
* @param request
* @param encoding encoding to be used to encode the request's query string
*/
public EncodedHttpServletRequest(HttpServletRequest request, String encoding) {
super(request);
this.request = request;
this.encoding = encoding;
}
public Map getParameterMap() {
if (paramMap == null) {
String queryString = request.getQueryString();
if (queryString == null) return Collections.unmodifiableMap(paramMap = new HashMap());
synchronized (this) {
if (paramMap == null) {
paramMap = new HashMap();
fillParameterMap(queryString);
}
}
}
return Collections.unmodifiableMap(paramMap);
}
private void fillParameterMap(String queryString) {
try {
String[] nvPair = queryString.split("&");
for (String pair : nvPair) {
String[] pairArr = pair.split("=");
String key = pairArr[0];
String value = URLDecoder.decode(pairArr[1], encoding) ;
if (paramMap.containsKey(key)) {
String[] valArr = (String[]) paramMap.get(key);
String[] newValArr = new String[valArr.length + 1];
System.arraycopy(valArr, 0, newValArr, 0, valArr.length);
newValArr[newValArr.length - 1] = value;
paramMap.put(key, newValArr);
}else {
paramMap.put(key, new String[] {value});
}
}
}catch(UnsupportedEncodingException ex) {
throw new RuntimeException(ex.getMessage(), ex);
}catch(Exception ex) {
throw new RuntimeException("Malformed query string: " + queryString, ex);
}
}
public String getParameter(String name) {
Object value = getParameterMap().get(name);
if (value == null)
return null;
return ((String[])getParameterMap().get(name))[0];
}
public String[] getParameterValues(String name) {
Object value = getParameterMap().get(name);
if (value == null)
return null;
return ((String[])getParameterMap().get(name));
}
public Enumeration getParameterNames() {
return Collections.enumeration(getParameterMap().keySet());
}
}
3- create that filter :
package com.forat.web.util;
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;
/**
* Set the encoding for the POST requests if one not specified by the incoming request
* @author mhewedy
*/
public class EncodingFilter implements Filter {
public void init(FilterConfig fConfig) throws ServletException {}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
String HTTP_METHOD = ((HttpServletRequest) request).getMethod();
if ("GET".equalsIgnoreCase(HTTP_METHOD)) {
// for GET requests
request = new EncodedHttpServletRequest((HttpServletRequest) request, "UTF-8");
}else if ("POST".equalsIgnoreCase(HTTP_METHOD)) {
// for Posted requests
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
}
chain.doFilter(request, response);
}
public void destroy() {}
}
and here's its mapping:
<filter>
<display-name>EncodingFilter</display-name>
<filter-name>EncodingFilter</filter-name>
<filter-class>com.forat.web.util.EncodingFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>EncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
<dispatcher>REQUEST</dispatcher>
<dispatcher>FORWARD</dispatcher>
<dispatcher>INCLUDE</dispatcher>
<dispatcher>ERROR</dispatcher>
</filter-mapping>
4- and here's the Servlet that accepts the User input:
package com.forat.web;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class SomeServlet
*/
public class SomeServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public SomeServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println(request.getParameter("username"));
}
}
Good luck :)
(for more comprehensive tutorial, please see http://www.arabteam2000-forum.com/index.php?showtopic=220589 (In Arabic) )
21 April 2010
How to send Query String throw the form GET method using specific encoding
In this post, I'll not talk much about Java, but about URL Encoding in General, although, I'll use java code to Illustrate that.
As you might know, the Get method of the HTTP protocol puts the query string in the request header.
example:
When you submit this form, the query string will looks like:
this appears for you in the browser navigation box.
for more info see:
http://en.wikipedia.org/wiki/Query_string and http://en.wikipedia.org/wiki/Percent-encoding
As it is clear from wiki links, not all characters can be included as is in the Query String, that characters get "URL Encoded" , and this URL encoding converts these characters in the form %HH, and this conversion (encoding) done based on the encoding schema, as the UTF-8 encoding schema encodes 'أ' to '%D8%A3' whereas other encoding such as ISO-8859-6 encodes it to '%C3'.
BTW, character 'أ', is the first character in the Arabic Language (proudly my native language).
The browser do URL Encoding to the Query String and sends this request to the server, So the server has to "Decode" this Query String back to the original characters to manipulate it as it's needs (inserts in db, etc ..)
Example:
index.html:
TestServlet.java
Try to change the encoding of index.html and TestServlet.jsp and notice the different encoding representations.
As you might know, the Get method of the HTTP protocol puts the query string in the request header.
example:
<html>
<head>
</head>
<body>
<form method="GET" action="/some/server">
<input type="text" name="name1" value="val1" />
<input type="text" name="name2" value="val2" />
<input type="text" name="name3" value="val3" />
<input type="submit" />
</form>
</body>
</html>
When you submit this form, the query string will looks like:
name1=val1&name2=val2&name3=val3
this appears for you in the browser navigation box.
for more info see:
http://en.wikipedia.org/wiki/Query_string and http://en.wikipedia.org/wiki/Percent-encoding
As it is clear from wiki links, not all characters can be included as is in the Query String, that characters get "URL Encoded" , and this URL encoding converts these characters in the form %HH, and this conversion (encoding) done based on the encoding schema, as the UTF-8 encoding schema encodes 'أ' to '%D8%A3' whereas other encoding such as ISO-8859-6 encodes it to '%C3'.
BTW, character 'أ', is the first character in the Arabic Language (proudly my native language).
The browser do URL Encoding to the Query String and sends this request to the server, So the server has to "Decode" this Query String back to the original characters to manipulate it as it's needs (inserts in db, etc ..)
Example:
index.html:
<html>
<head>
<meta http-equiv='Content-Type' content='text/html; charset=UTF-8'>
</head>
<body>
<form method="GET" action="TestServlet" accept-charset="UTF-8" >
<input type="text" name="name1" /> <!-- put here any non-ascii char, ex أ >
<input type="submit" />
</form>
</body>
</html>
TestServlet.java
package com.forat;
import java.io.IOException;
import java.net.URLDecoder;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String qString = request.getQueryString();
System.out.println("Raw Query String: " + qString);
System.out.println("Decoded Query String: " + URLDecoder.decode(qString, "UTF-8"));
}
}
Try to change the encoding of index.html and TestServlet.jsp and notice the different encoding representations.
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