分享程序员开发的那些事...
更新时间：2022-05-09 02:53:03
1.useBean标签的使用
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jsp:useBean标签的使用</title>
</head>
<body>
<!-- 如果没有实例化person对象，那么就将id存入scope对应的对象中，下次访问时从对象中取出相应的实例
如果实例化了，就取出了person实例（其实都详单与new一个person类）-->
<jsp:useBean id="person" class="cn.edu.domain.Person" scope="session">
<h4>创建了一个person对象！！！</h4> <!-- 如果是session，这句话只出现一次，就是创建session那一次 -->
</jsp:useBean>
<%=person.getName() %>
</body>
</html>
2.setProperty标签的使用
名为Person的JavaBean:
package cn.edu.domain;
import java.util.Date;
public class Person {
private String name="aaa";
private int age;
private Date brithday;
private Address address;
public Person(){}
public Person(String name) {
this.name = name;
}
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;
}
public Date getBrithday() {
return brithday;
}
public void setBrithday(Date brithday) {
this.brithday = brithday;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
}
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jsp:setProperty标签的使用</title>
</head>
<body>
<jsp:useBean id="person" class="cn.edu.domain.Person" scope="page"/>
<!-- 手工为bean赋值 -->
<jsp:setProperty property="name" name="person" value="XXXXX"/>
<%=person.getName() %><br/>
<!-- 请求参数为bean的属性赋值 (URL路径带的值，如http://localhost:8080/day09/Jsp2.jsp?name=jack&&age=12)-->
<jsp:setProperty property="name" name="person" param="name"/>
<!-- 支持8中基础数据类型的转换，把客户机提交的字符串，转换成相应的8中基础类型，赋到bean的属性中 -->
<jsp:setProperty property="age" name="person" param="age"/>
<jsp:setProperty property="brithday" name="person" value="<%=new Date() %>"/>
<%=person.getName() %><br/>
<%=person.getAge() %><br/>
<%=person.getBrithday()%><br/>
<hr/>
<!-- 用所有的请求参数为bean赋值 -->
<jsp:setProperty property="*" name="person"/>
<%=person.getName() %><br/>
<%=person.getAge() %><br/>
<hr/>
<!-- 用getproperty标签取bean的值 -->
<jsp:getProperty property="name" name="person"/><br/>
<jsp:getProperty property="age" name="person"/><br/>
<jsp:getProperty property="brithday" name="person"/><br/>
</body>
</html>