With this example we are going to demonstrate how to use a Bean in a JSP page. JavaServer Pages (JSP) is a server-side programming technology that enables the creation of dynamic, platform-independent method for building Web-based applications. JSP have access to the entire family of Java APIs, including the JDBC API to access enterprise databases. In short, to use a Bean in a JSP page you should:
- Create a Java Bean. The Java Bean is a specially constructed Java class that provides a default, no-argument constructor, implements the Serializable interface and it has getter and setter methods for its properties.
- Create a jsp page, using the
<%code fragment%>scriptlet. It can contain any number of JAVA language statements, variable or method declarations, or expressions that are valid in the page scripting language. - Use the
useBeanaction to declare the JavaBean for use in the JSP page. Once declared, the bean becomes a scripting variable that can be accessed by both scripting elements and other custom tags used in the JSP. - Use the
getPropertyaction to access get methods andsetPropertyaction to access set methods of the bean.
Let’s take a look at the code snippets of a sample Bean and a JSP page that uses it, below:
SampleBean.java
package com.javacodegeeks.snippets.enterprise;
import java.util.Date;
public class SampleBean {
private String param1;
private Date param2 = new Date();
public String getParam1() {
return param1;
}
public void setParam1(String param1) {
this.param1 = param1;
}
public Date getParam2() {
return param2;
}
public void setParam2(Date param2) {
this.param2 = param2;
}
@Override
public String toString() {
return "SampleBean [param1=" + param1 + ", param2=" + param2 + "]";
}
}
UseBean.jsp
<%@ page language="java" contentType="text/html;charset=UTF-8" %> <%@ page import="com.javacodegeeks.snippets.enterprise.SampleBean"%> <html> <head> <title>Java Code Geeks Snippets - Use a Bean in JSP Page</title> </head> <body> <jsp:useBean id="sampleBean" class="com.javacodegeeks.snippets.enterprise.SampleBean" scope="session"> <%-- intialize bean properties --%> <jsp:setProperty name="sampleBean" property="param1" value="value1" /> </jsp:useBean> Sample Bean: <%= sampleBean %> param1: <jsp:getProperty name="sampleBean" property="param1" /> param2: <jsp:getProperty name="sampleBean" property="param2" /> </body>
URL:
http://myhost:8080/jcgsnippets/UseBean.jsp
Output:
Sample Bean: SampleBean [param1=value1, param2=Thu Nov 17 21:28:03 EET 2011]
param1: value1 param2: Thu Nov 17 21:28:03 EET 2011
This was an example of how to use a Bean in a JSP page.
