[9.4] Jsp:useBean, jsp:setProperty and jsp:getProperty action tag

Jsp:useBean, jsp:setProperty and jsp:getProperty action tag

jsp:useBean action tag:

jsp:useBean action tag is used to instantiate a bean class. It first search for an existing instance using id and scope variables. If object is not found than it creates bean class object.

Commonly used attributes of jsp:useBean:

1. id: This attribute is used to uniquely identify the bean class within the specified block.
2. scope: This attribute represents the scope of the bean. Scope may page (default scope), request, session or application.
3. class: This attribute specifies the full package name of the bean.
Syntax:  

 jsp:setProperty action tag:

jsp:setProperty action tag is used to set the value of the specified bean property.

Commonly used attributes of jsp:setProperty:

1. name: This attribute refers to the bean class.property: This attribute specifies the bean property whose value is to be set.
2. value: This attribute specifies the value set to the bean property.
Syntax:    

jsp:getProperty action tag:

jsp:getProperty action tag is used to get the value of the specified bean property and insert it into output.

Commonly used attributes of jsp:getProperty:

1. name: This attribute refers to the bean class.
2. property: This attribute specifies the bean property whose value is to be retrieve.
Syntax:

Example:

test.jsp
<html>
 <head>
  <title>useBean,setProperty and getProperty action example</title>
 </head>
 <body>
  <h4>Enter student detail.</h4> 
  <form action="display.jsp" method="post"> 
  Name:  <input type="text" name="name"><br/><br/> 
  RollNo: <input type="text" name="rollNo"><br/><br/> 
  <input type="submit" value="Sign up"> 
  </form> 
 </body>
</html>
StudentBean.java
/**
 * This class is act as a java bean for a student.
 * @author javawithease
 */
public class StudentBean {
 //student properties
 private String name;
 private String rollNo;
 
 //no-argument constructor
 public StudentBean(){
 
 }
 
 public String getName() {
  return name;
 }
 
 public void setName(String name) {
  this.name = name;
 }
 
 public String getRollNo() {
  return rollNo;
 }
 
 public void setRollNo(String rollNo) {
  this.rollNo = rollNo;
 } 
}
display.jsp
<html>
 <head>
  <title>useBean,setProperty and getProperty action example</title>
 </head>
 <body>
  <h4>Student detail:</h4>
  <jsp:useBean id="student"
                           class="com.javawithease.business.StudentBean"/>
         <jsp:setProperty name="student" property="*"/>
         Name:<jsp:getProperty name="student" property="name"/><br>
         RollNo:<jsp:getProperty name="student" property="rollNo"/><br>
 </body>
</html>
web.xml
<web-app>
 
  <welcome-file-list>
          <welcome-file>test.jsp</welcome-file>
  </welcome-file-list> 
 
</web-app>

Output:


Enter Name and RollNo:

 Click on Sign up button: