在jsp页面中使用javaBean:三个标签；
<jsp:useBean>标签
<jsp:setProperty>标签
<jsp:getProperty>标签
首先建立一个customer类：
package com.lanqiao.javatest;
public class Customer {
private Integer id;
private String name;
private int age;
public Customer() {
super();
// TODO Auto-generated constructor stub
}
public Customer(Integer id, String name, int age) {
super();
this.id = id;
this.name = name;
this.age = age;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Customer [id=" + id + ", name=" + name + ", age=" + age + "]";
}
}
建立一个jsp页面：直接调用customer的属性和方法，并且可以给属性赋值；
<%@page import="com.atguigu.javaweb.Customer"%>
<%@ 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> <jsp:useBean id="customer" class="com.lanqiao.javatest.Customer"
scope="request"></jsp:useBean> <jsp:useBean id="customer2" beanName="com.lanqiao.javatest.Customer"
type="java.lang.Object" scope="request"></jsp:useBean> <%--
Object customer2 = request.getAttribute("customer2");
if(customer2){
customer2 = Class.forName("com.lanqiao.javatest.Customer").newInstance();
request.setAttribute("customer2", customer2);
}
--%> <!-- 若 property 的值为 *, 省略 value 属性值, 则将自动为所有属性赋值为对应的请求参数的值. -->
<jsp:setProperty property="*" name="customer"/> <%--
<jsp:setProperty property="name" value="ATGUIGU2" name="customer"/>
--%> age: <jsp:getProperty property="age" name="customer"/>
<br>
name: <jsp:getProperty property="name" name="customer"/>
<br>
id: <jsp:getProperty property="id" name="customer"/> <%--
<%= customer.getAge() %>
--%> <%--
customer.setAge(10);
--%> <%--
//1. 从 scope(session) 中获取 id(customer) 属性值, 赋给 class(com.lanqiao.javatest.Customer)
//类型的 id(customer) 变量
Customer customer = (Customer)session.getAttribute("customer"); //2. 若属性值为 null, 则利用反射创建一个新的对象, 把该对象赋给 id(customer), 并以 id(customer)
//为属性名让如到 scope(session) 中.
if(customer == null){
customer = (Customer)Class.forName("com.lanqiao.javatest.Customer").newInstance();
session.setAttribute("customer", customer);
}
--%> </body>
</html>