Thursday 20 June 2013

Advanced JSP

JSP - Database Access

This tutorial assumes you have good understanding on how JDBC application works. Before starting with database access through a JSP, make sure you have proper JDBC environment setup along with a database.
For more detail on how to access database using JDBC and its environment setup you can go through our JDBC Tutorial.
To start with basic concept, let us create a simple table and create few records in that table as follows:

Create Table

To create the Employees table in EMP database, use the following steps:

Step 1:

Open a Command Prompt and change to the installation directory as follows:
C:\>
C:\>cd Program Files\MySQL\bin
C:\Program Files\MySQL\bin>

Step 2:

Login to database as follows
C:\Program Files\MySQL\bin>mysql -u root -p
Enter password: ********
mysql>

Step 3:

Create the table Employee in TEST database as follows:
mysql> use TEST;
mysql> create table Employees
    (
     id int not null,
     age int not null,
     first varchar (255),
     last varchar (255)
    );
Query OK, 0 rows affected (0.08 sec)
mysql>

Create Data Records

Finally you create few records in Employee table as follows:
mysql> INSERT INTO Employees VALUES (100, 18, 'Zara', 'Ali');
Query OK, 1 row affected (0.05 sec)
 
mysql> INSERT INTO Employees VALUES (101, 25, 'Mahnaz', 'Fatma');
Query OK, 1 row affected (0.00 sec)
 
mysql> INSERT INTO Employees VALUES (102, 30, 'Zaid', 'Khan');
Query OK, 1 row affected (0.00 sec)
 
mysql> INSERT INTO Employees VALUES (103, 28, 'Sumit', 'Mittal');
Query OK, 1 row affected (0.00 sec)
 
mysql>

SELECT Operation:

Following example shows how we can execute SQL SELECT statement using JTSL in JSP programming:
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
 
<html>
<head>
<title>SELECT Operation</title>
</head>
<body>
 
<sql:setDataSource var="snapshot" driver="com.mysql.jdbc.Driver"
     url="jdbc:mysql://localhost/TEST"
     user="root"  password="pass123"/>
 
<sql:query dataSource="${snapshot}" var="result">
SELECT * from Employees;
</sql:query>
 
<table border="1" width="100%">
<tr>
   <th>Emp ID</th>
   <th>First Name</th>
   <th>Last Name</th>
   <th>Age</th>
</tr>
<c:forEach var="row" items="${result.rows}">
<tr>
   <td><c:out value="${row.id}"/></td>
   <td><c:out value="${row.first}"/></td>
   <td><c:out value="${row.last}"/></td>
   <td><c:out value="${row.age}"/></td>
</tr>
</c:forEach>
</table>
 
</body>
</html>
Now try to access above JSP, which should display the following result:
Emp IDFirst NameLast NameAge
100ZaraAli18
101MahnazFatma25
102ZaidKhan30
103SumitMittal28

INSERT Operation:

Following example shows how we can execute SQL INSERT statement using JTSL in JSP programming:
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
 
<html>
<head>
<title>JINSERT Operation</title>
</head>
<body>
 
<sql:setDataSource var="snapshot" driver="com.mysql.jdbc.Driver"
     url="jdbc:mysql://localhost/TEST"
     user="root"  password="pass123"/>


<sql:update dataSource="${snapshot}" var="result">
INSERT INTO Employees VALUES (104, 2, 'Nuha', 'Ali');
</sql:update>
 
<sql:query dataSource="${snapshot}" var="result">
SELECT * from Employees;
</sql:query>
 
<table border="1" width="100%">
<tr>
   <th>Emp ID</th>
   <th>First Name</th>
   <th>Last Name</th>
   <th>Age</th>
</tr>
<c:forEach var="row" items="${result.rows}">
<tr>
   <td><c:out value="${row.id}"/></td>
   <td><c:out value="${row.first}"/></td>
   <td><c:out value="${row.last}"/></td>
   <td><c:out value="${row.age}"/></td>
</tr>
</c:forEach>
</table>
 
</body>
</html>
Now try to access above JSP, which should display the following result:
Emp IDFirst NameLast NameAge
100ZaraAli18
101MahnazFatma25
102ZaidKhan30
103SumitMittal28
104NuhaAli2

DELETE Operation:

Following example shows how we can execute SQL DELETE statement using JTSL in JSP programming:
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
 
<html>
<head>
<title>DELETE Operation</title>
</head>
<body>
 
<sql:setDataSource var="snapshot" driver="com.mysql.jdbc.Driver"
     url="jdbc:mysql://localhost/TEST"
     user="root"  password="pass123"/>
 
<c:set var="empId" value="103"/>
 
<sql:update dataSource="${snapshot}" var="count">
  DELETE FROM Employees WHERE Id = ?
  <sql:param value="${empId}" />
</sql:update>
 
<sql:query dataSource="${snapshot}" var="result">
   SELECT * from Employees;
</sql:query>
 
<table border="1" width="100%">
<tr>
   <th>Emp ID</th>
   <th>First Name</th>
   <th>Last Name</th>
   <th>Age</th>
</tr>
<c:forEach var="row" items="${result.rows}">
<tr>
   <td><c:out value="${row.id}"/></td>
   <td><c:out value="${row.first}"/></td>
   <td><c:out value="${row.last}"/></td>
   <td><c:out value="${row.age}"/></td>
</tr>
</c:forEach>
</table>
 
</body>
</html>
Now try to access above JSP, which should display the following result:
Emp IDFirst NameLast NameAge
100ZaraAli18
101MahnazFatma25
102ZaidKhan30

UPDATE Operation:

Following example shows how we can execute SQL UPDATE statement using JTSL in JSP programming:
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
 
<html>
<head>
<title>DELETE Operation</title>
</head>
<body>
 
<sql:setDataSource var="snapshot" driver="com.mysql.jdbc.Driver"
     url="jdbc:mysql://localhost/TEST"
     user="root"  password="pass123"/>
 
<c:set var="empId" value="102"/>
 
<sql:update dataSource="${snapshot}" var="count">
  UPDATE Employees SET last = 'Ali'
  <sql:param value="${empId}" />
</sql:update>
 
<sql:query dataSource="${snapshot}" var="result">
   SELECT * from Employees;
</sql:query>
 
<table border="1" width="100%">
<tr>
   <th>Emp ID</th>
   <th>First Name</th>
   <th>Last Name</th>
   <th>Age</th>
</tr>
<c:forEach var="row" items="${result.rows}">
<tr>
   <td><c:out value="${row.id}"/></td>
   <td><c:out value="${row.first}"/></td>
   <td><c:out value="${row.last}"/></td>
   <td><c:out value="${row.age}"/></td>
</tr>
</c:forEach>
</table>
 
</body>
</html>
Now try to access above JSP, which should display the following result:
Emp IDFirst NameLast NameAge
100ZaraAli18
101MahnazFatma25
102ZaidAli30

JSP - XML Data

When you send XML data via HTTP, it makes sense to use JSP to handle incoming and outgoing XML documents for example RSS documents. As an XML document is merely a bunch of text, creating one through a JSP is no more difficult than creating an HTML document.

Sending XML from a JSP:

You can send XML content using JSPs the same way you send HTML. The only difference is that you must set the content type of your page to text/xml. To set the content type, use the <%@page%> tag, like this:
<%@ page contentType="text/xml" %>
Following is a simple example to send XML content to the browser:
<%@ page contentType="text/xml" %>

<books>
   <book>
      <name>Padam History</name>
      <author>ZARA</author>
      <price>100</price>
   </book>
</books>
Try to access above XML using different browsers to see the document tree presentation of the above XML.

Processing XML in JSP:

Before you proceed with XML processing using JSP, you would need to copy following two XML and XPath related libraries into your <Tomcat Installation Directory>\lib:
Let us put following content in books.xml file:
<books>
<book>
  <name>Padam History</name>
  <author>ZARA</author>
  <price>100</price>
</book>
<book>
  <name>Great Mistry</name>
  <author>NUHA</author>
  <price>2000</price>
</book>
</books>
Now try the following main.jsp, keeping in the same directory:
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="x" uri="http://java.sun.com/jsp/jstl/xml" %>
 
<html>
<head>
  <title>JSTL x:parse Tags</title>
</head>
<body>
<h3>Books Info:</h3>
<c:import var="bookInfo" url="http://localhost:8080/books.xml"/>
 
<x:parse xml="${bookInfo}" var="output"/>
<b>The title of the first book is</b>: 
<x:out select="$output/books/book[1]/name" />
<br>
<b>The price of the second book</b>: 
<x:out select="$output/books/book[2]/price" />
 
</body>
</html>
Now try to access above JSP using http://localhost:8080/main.jsp, this would produce following result:

BOOKS INFO:

The title of the first book is:Padam History
The price of the second book: 2000

Formatting XML with JSP:

Consider the following XSLT stylesheet style.xsl:
<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl=
"http://www.w3.org/1999/XSL/Transform" version="1.0">
 
<xsl:output method="html" indent="yes"/>
 
<xsl:template match="/">
  <html>
  <body>
   <xsl:apply-templates/>
  </body>
  </html>
</xsl:template>
 
<xsl:template match="books">
  <table border="1" width="100%">
    <xsl:for-each select="book">
      <tr>
        <td>
          <i><xsl:value-of select="name"/></i>
        </td>
        <td>
          <xsl:value-of select="author"/>
        </td>
        <td>
          <xsl:value-of select="price"/>
        </td>
      </tr>
    </xsl:for-each>
  </table>
</xsl:template>
</xsl:stylesheet>
Now consider the following JSP file:
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="x" uri="http://java.sun.com/jsp/jstl/xml" %>
 
<html>
<head>
  <title>JSTL x:transform Tags</title>
</head>
<body>
<h3>Books Info:</h3>
<c:set var="xmltext">
  <books>
    <book>
      <name>Padam History</name>
      <author>ZARA</author>
      <price>100</price>
    </book>
    <book>
      <name>Great Mistry</name>
      <author>NUHA</author>
      <price>2000</price>
    </book>
  </books>
</c:set>
 
<c:import url="http://localhost:8080/style.xsl" var="xslt"/>
<x:transform xml="${xmltext}" xslt="${xslt}"/>
 
</body>
</html>
This would produce following result:

BOOKS INFO:

Padam HistoryZARA100
Great MistryNUHA2000
For more detail on XML processing using JSTL, you can check JSP Standard Tag Library.

JSP - JavaBeans

A JavaBean is a specially constructed Java class written in the Java and coded according to the JavaBeans API specifications.
Following are the unique characteristics that distinguish a JavaBean from other Java classes:
  • It provides a default, no-argument constructor.
  • It should be serializable and implement the Serializable interface.
  • It may have a number of properties which can be read or written.
  • It may have a number of "getter" and "setter" methods for the properties.

JavaBeans Properties:

A JavaBean property is a named attribute that can be accessed by the user of the object. The attribute can be of any Java data type, including classes that you define.
A JavaBean property may be read, write, read only, or write only. JavaBean properties are accessed through two methods in the JavaBean's implementation class:
MethodDescription
getPropertyName()For example, if property name is firstName, your method name would be getFirstName() to read that property. This method is called accessor.
setPropertyName()For example, if property name is firstName, your method name would be setFirstName() to write that property. This method is called mutator.
A read-only attribute will have only a getPropertyName() method, and a write-only attribute will have only a setPropertyName() method.

JavaBeans Example:

Consider a student class with few properties:
package com.only4programmers.blogspot;

public class StudentsBean implements java.io.Serializable
{
   private String firstName = null;
   private String lastName = null;
   private int age = 0;

   public StudentsBean() {
   }
   public String getFirstName(){
      return firstName;
   }
   public String getLastName(){
      return lastName;
   }
   public int getAge(){
      return age;
   }
   public void setFirstName(String firstName){
      this.firstName = firstName;
   }
   public void setLastName(String lastName){
      this.lastName = lastName;
   }
   public void setAge(Integer age){
      this.age = age;
   }
}

Accessing JavaBeans:

The useBean action declares a JavaBean for use in a JSP. Once declared, the bean becomes a scripting variable that can be accessed by both scripting elements and other custom tags used in the JSP. The full syntax for the useBean tag is as follows:
<jsp:useBean id="bean's name" scope="bean's scope" typeSpec/>
Here values for the scope attribute could be page, request, session or application based on your requirement. The value of the id attribute may be any value as a long as it is a unique name among other useBean declarations in the same JSP.
Following example shows its simple usage:
<html>
<head>
<title>useBean Example</title>
</head>
<body>

<jsp:useBean id="date" class="java.util.Date" /> 
<p>The date/time is <%= date %>

</body>
</html>
This would produce following result:
The date/time is Thu Sep 30 11:18:11 GST 2010 

Accessing JavaBeans Properties:

Along with <jsp:useBean...>, you can use <jsp:getProperty/> action to access get methods and <jsp:setProperty/> action to access set methods. Here is the full syntax:
<jsp:useBean id="id" class="bean's class" scope="bean's scope">
   <jsp:setProperty name="bean's id" property="property name"  
                    value="value"/>
   <jsp:getProperty name="bean's id" property="property name"/>
   ...........
</jsp:useBean>
The name attribute references the id of a JavaBean previously introduced to the JSP by the useBean action. The property attribute is the name of the get or set methods that should be invoked.
Following is a simple example to access the data using above syntax:
<html>
<head>
<title>get and set properties Example</title>
</head>
<body>

<jsp:useBean id="students" 
                    class="com.yourdomain.StudentsBean"> 
   <jsp:setProperty name="students" property="firstName"
                    value="Zara"/>
   <jsp:setProperty name="students" property="lastName" 
                    value="Ali"/>
   <jsp:setProperty name="students" property="age" 
                    value="10"/>
</jsp:useBean>

<p>Student First Name: 
   <jsp:getProperty name="students" property="firstName"/>
</p>
<p>Student Last Name: 
   <jsp:getProperty name="students" property="lastName"/>
</p>
<p>Student Age: 
   <jsp:getProperty name="students" property="age"/>
</p>

</body>
</html>
Let us make StudentsBean.class available in CLASSPATH and try to access above JSP. This would produce following result:
Student First Name: Zara 

Student Last Name: Ali 

Student Age: 10 

JSP - Exception Handling

When you are writing JSP code, a programmer may leave a coding errors which can occur at any part of the code. You can have following type of errors in your JSP code:
  • Checked exceptions: Achecked exception is an exception that is typically a user error or a problem that cannot be foreseen by the programmer. For example, if a file is to be opened, but the file cannot be found, an exception occurs. These exceptions cannot simply be ignored at the time of compilation.
  • Runtime exceptions: A runtime exception is an exception that occurs that probably could have been avoided by the programmer. As opposed to checked exceptions, runtime exceptions are ignored at the time of compliation.
  • Errors: These are not exceptions at all, but problems that arise beyond the control of the user or the programmer. Errors are typically ignored in your code because you can rarely do anything about an error. For example, if a stack overflow occurs, an error will arise. They are also ignored at the time of compilation.
This tutorial will give you few simple and elegant ways to handle run time exception/error occuring in your JSP code.

Using Exception Object:

The exception object is an instance of a subclass of Throwable (e.g., java.lang. NullPointerException) and is only available in error pages. Following is the list of important medthods available in the Throwable class.
SNMethods with Description
1public String getMessage()
Returns a detailed message about the exception that has occurred. This message is initialized in the Throwable constructor.
2public Throwable getCause()
Returns the cause of the exception as represented by a Throwable object.
3public String toString()
Returns the name of the class concatenated with the result of getMessage()
4public void printStackTrace()
Prints the result of toString() along with the stack trace to System.err, the error output stream.
5public StackTraceElement [] getStackTrace()
Returns an array containing each element on the stack trace. The element at index 0 represents the top of the call stack, and the last element in the array represents the method at the bottom of the call stack.
6public Throwable fillInStackTrace()
Fills the stack trace of this Throwable object with the current stack trace, adding to any previous information in the stack trace.
JSP gives you an option to specify Error Page for each JSP. Whenever the page throws an exception, the JSP container automatically invokes the error page.
Following is an example to specifiy an error page for a main.jsp. To set up an error page, use the <%@ page errorPage="xxx" %> directive.
<%@ page errorPage="ShowError.jsp" %>

<html>
<head>
   <title>Error Handling Example</title>
</head>
<body>
<%
   // Throw an exception to invoke the error page
   int x = 1;
   if (x == 1)
   {
      throw new RuntimeException("Error condition!!!");
   }
%>
</body>
</html>
Now you would have to write one Error Handling JSP ShowError.jsp, which is given below. Notice that the error-handling page includes the directive <%@ page isErrorPage="true" %>. This directive causes the JSP compiler to generate the exception instance variable.
<%@ page isErrorPage="true" %>
<html>
<head>
<title>Show Error Page</title>
</head>
<body>
<h1>Opps...</h1>
<p>Sorry, an error occurred.</p>
<p>Here is the exception stack trace: </p>
<pre>
<% exception.printStackTrace(response.getWriter()); %>
</pre>
</body>
</html>
Now try to access main.jsp, it should generate something as follows:
java.lang.RuntimeException: Error condition!!!
......

Opps...
Sorry, an error occurred.

Here is the exception stack trace:

Using JSTL tags for Error Page:

You can make use of JSTL tags to write an error page ShowError.jsp. This page has almost same logic which we have used in above example, but it has better structure and it provides more information:
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@page isErrorPage="true" %>
<html>
<head>
<title>Show Error Page</title>
</head>
<body>
<h1>Opps...</h1>
<table width="100%" border="1">
<tr valign="top">
<td width="40%"><b>Error:</b></td>
<td>${pageContext.exception}</td>
</tr>
<tr valign="top">
<td><b>URI:</b></td>
<td>${pageContext.errorData.requestURI}</td>
</tr>
<tr valign="top">
<td><b>Status code:</b></td>
<td>${pageContext.errorData.statusCode}</td>
</tr>
<tr valign="top">
<td><b>Stack trace:</b></td>
<td>
<c:forEach var="trace" 
         items="${pageContext.exception.stackTrace}">
<p>${trace}</p>
</c:forEach>
</td>
</tr>
</table>
</body>
</html>
Now try to access main.jsp, it should generate something as follows:

Opps...

Error:java.lang.RuntimeException: Error condition!!!
URI:/main.jsp
Status code:500
Stack trace:
org.apache.jsp.main_jsp._jspService(main_jsp.java:65)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:68)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
...................

Using Try...Catch Block:

If you want to handle errors with in the same page and want to take some action instead of firing an error page, you can make use of try....catch block.
Following is a simple example which shows how to use try...catch block. Let us put following code in main.jsp:
<html>
<head>
   <title>Try...Catch Example</title>
</head>
<body>
<%
   try{
      int i = 1;
      i = i / 0;
      out.println("The answer is " + i);
   }
   catch (Exception e){
      out.println("An exception occurred: " + e.getMessage());
   }
%>
</body>
</html>
Now try to access main.jsp, it should generate something as follows:
An exception occurred: / by zero 

JSP - Internationalization| i18n| l10n

Before we proceed, let me explain three important terms:
  • Internationalization (i18n): This means enabling a web site to provide different versions of content translated into the visitor's language or nationality.
  • Localization (l10n): This means adding resources to a web site to adapt it to a particular geographical or cultural region for example Hindi translation to a web site.
  • locale: This is a particular cultural or geographical region. It is usually referred to as a language symbol followed by a country symbol which are separated by an underscore. For example "en_US" represents english locale for US.
There are number of items which should be taken care while building up a global website. This tutorial would not give you complete detail on this but it would give you a good example on how you can offer your web page in different languages to internet community by differentiating their location ie. locale.
A JSP can pickup appropriate version of the site based on the requester's locale and provide appropriate site version according to the local language, culture and requirements. Following is the method of request object which returns Locale object.
java.util.Locale request.getLocale() 

Detecting Locale:

Following are the important locale methods which you can use to detect requester's location, language and of course locale. All the below methods display country name and language name set in requester's browser.
S.N.Method & Description
1String getCountry()
This method returns the country/region code in upper case for this locale in ISO 3166 2-letter format.
2String getDisplayCountry()
This method returns a name for the locale's country that is appropriate for display to the user.
3String getLanguage()
This method returns the language code in lower case for this locale in ISO 639 format.
4String getDisplayLanguage()
This method returns a name for the locale's language that is appropriate for display to the user.
5String getISO3Country()
This method returns a three-letter abbreviation for this locale's country.
6String getISO3Language()
This method returns a three-letter abbreviation for this locale's language.

Example:

This example shows how you display a language and associated country for a request in a JSP:
<%@ page import="java.io.*,java.util.Locale" %>
<%@ page import="javax.servlet.*,javax.servlet.http.* "%>
<%
   //Get the client's Locale
   Locale locale = request.getLocale();
   String language = locale.getLanguage();
   String country = locale.getCountry();
%>
<html>
<head>
<title>Detecting Locale</title>
</head>
<body>
<center>
<h1>Detecting Locale</h1>
</center>
<p align="center">
<% 
   out.println("Language : " + language  + "<br />");
   out.println("Country  : " + country   + "<br />");
%>
</p>
</body>
</html>

Languages Setting:

A JSP can output a page written in a Western European language such as English, Spanish, German, French, Italian, Dutch etc. Here it is important to set Content-Language header to display all the characters properly.
Second point is to display all the special characters using HTML entities, For example, "&#241;" represents "ñ", and "&#161;" represents "¡" as follows:
<%@ page import="java.io.*,java.util.Locale" %>
<%@ page import="javax.servlet.*,javax.servlet.http.* "%>
<%
    // Set response content type
    response.setContentType("text/html");
    // Set spanish language code.
    response.setHeader("Content-Language", "es");
    String title = "En Español";

%>
<html>
<head>
<title><%  out.print(title); %></title>
</head>
<body>
<center>
<h1><%  out.print(title); %></h1>
</center>
<div align="center">
<p>En Español</p>
<p>¡Hola Mundo!</p>
</div>
</body>
</html>

Locale Specific Dates:

You can use the java.text.DateFormat class and its static getDateTimeInstance( ) method to format date and time specific to locale. Following is the example which shows how to format dates specific to a given locale:
<%@ page import="java.io.*,java.util.Locale" %>
<%@ page import="javax.servlet.*,javax.servlet.http.* "%>
<%@ page import="java.text.DateFormat,java.util.Date" %>

<%
    String title = "Locale Specific Dates";
    //Get the client's Locale
    Locale locale = request.getLocale( );
    String date = DateFormat.getDateTimeInstance(
                                  DateFormat.FULL, 
                                  DateFormat.SHORT, 
                                  locale).format(new Date( ));
%>
<html>
<head>
<title><% out.print(title); %></title>
</head>
<body>
<center>
<h1><% out.print(title); %></h1>
</center>
<div align="center">
<p>Local Date: <%  out.print(date); %></p>
</div>
</body>
</html>

Locale Specific Currency

You can use the java.txt.NumberFormat class and its static getCurrencyInstance( ) method to format a number, such as a long or double type, in a locale specific curreny. Following is the example which shows how to format currency specific to a given locale:
<%@ page import="java.io.*,java.util.Locale" %>
<%@ page import="javax.servlet.*,javax.servlet.http.* "%>
<%@ page import="java.text.NumberFormat,java.util.Date" %>

<%
    String title = "Locale Specific Currency";
    //Get the client's Locale
    Locale locale = request.getLocale( );
    NumberFormat nft = NumberFormat.getCurrencyInstance(locale);
    String formattedCurr = nft.format(1000000);
%>
<html>
<head>
<title><% out.print(title); %></title>
</head>
<body>
<center>
<h1><% out.print(title); %></h1>
</center>
<div align="center">
<p>Formatted Currency: <%  out.print(formattedCurr); %></p>
</div>
</body>
</html>

Locale Specific Percentage

You can use the java.txt.NumberFormat class and its static getPercentInstance( ) method to get locale specific percentage. Following is the example which shows how to format percentage specific to a given locale:
<%@ page import="java.io.*,java.util.Locale" %>
<%@ page import="javax.servlet.*,javax.servlet.http.* "%>
<%@ page import="java.text.NumberFormat,java.util.Date" %>

<%
    String title = "Locale Specific Percentage";
    //Get the client's Locale
    Locale locale = request.getLocale( );
    NumberFormat nft = NumberFormat.getPercentInstance(locale);
    String formattedPerc = nft.format(0.51);
%>
<html>
<head>
<title><% out.print(title); %></title>
</head>
<body>
<center>
<h1><% out.print(title); %></h1>
</center>
<div align="center">
<p>Formatted Percentage: <%  out.print(formattedPerc); %></p>
</div>
</body>
</html>