JSP STANDARD ACTION jsp:setProperty

                                          <jsp:setProperty>         
Introduction:

1.    The <jsp:setProperty> element sets the value of one or more properties in a Bean, using the Bean's setter methods.

2.    You must declare the Bean with <jsp:useBean> before you set a property value with <jsp:setProperty>. Because <jsp:useBean> and <jsp:setProperty> work together.

3.    the Bean instance names they use must match (that is, the value of name in <jsp:setProperty> and the value of id in <jsp:useBean> must be the same).

Syntax:

<jsp:setProperty name = “bean instance name” property = “name” value = “vlaue”>

Description:

1.    We can use this standard action in the following combinations.

<jsp:setProperty property="uname" name="b" value="myjavahub0001"/>

2.    It retrieves the value of request parameter and assign it to the specified bean property.

<jsp:setProperty property="uname" name="b" param="username" />

3.    If the request parameter Name matches with bean property Name then it is not required to use param attribute .

<jsp:setProperty  property="uname" name="b" /> 

4.    <jsp:setProperty property="*" name="b"/>

‘*’ specifies all properties of the bean

Note: It iterates through all request parameters and it any parameter name matched with bean property name then assigns request parameter value through the bean property.

  

Attributes:

1.    Name:

It represents the name of the bean object whose property has to set.This is exactly same as id attribute <jsp:useBean>,It is the mandatory attribute.

2.Property:

The name of the java bean property which has to set.It is the mandatory attribute.

3. Value:

 It specifies the value which has to set to the java bean property.It is optional attribute and never becomes in combination with param attribute.

4.  Param:

 It represents the name of the request parameter whose value has to set to the    bean property. It is optional attribute and never comes in combination with value attribute.

Example: login.jsp

<body > <form action = "/Scwcd_jsp/test.jsp"> Enter name: <input type = 'text' name = "uname"> <br> Enter mail   : <input type = 'text' name = "mail"> <br> Enter age: <input type = 'text' name = "age"><br> <input type = "submit"> </form> </body>

 test.jsp

<jsp:useBean id="b" class="com.myjavahub.SimpleBean"></jsp:useBean> <jsp:setProperty property="mail" name="b" value="chamu001@gmail.com"/> <jsp:setProperty property="*" name="b"/> <table border=2> <tr><td><h2>property</h2></td><td><h2>value</h2></td></tr> <tr><td><h2>User Name</h2></td><td><h2><%= b.getUname()%></h2></td></tr> <tr><td><h2>Age</h2></td><td><h2><%= b.getAge()%></h2></td></tr> <tr><td><h2>Mail Id</h2></td><td><h2><%= b.getMail()%></h2></td></tr> </table>

SimpleBean.java

package com.myjavahub; public class SimpleBean {           private String uname ;           private int  age;           private String mail ;                     public int getAge() {                    return age;           }           public void setAge(int age) {                    this.age = age;            }    public String getUname() {                    return uname;           }           public void setUname(String uname) {                    this.uname = uname;           }                     public String getMail() {                    return mail;           }           public void setMail(String mail) {                    this.mail = mail;           } }

Output:  http://localhost:8080/Scwcd_jsp/login.jsp

Enter name,mail,age and click on submit button :

  

 Note: All the required type conversions will take care by automatically by the <jsp:setProperty>  :(string to int).

Note: It is always a good programming practice to maintain form parameter name are exactly same as bean property names.