Struts2-整理笔记Action生命周期如何获取参数（3种）集合类型参数封装
Posted
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了Struts2-整理笔记Action生命周期如何获取参数（3种）集合类型参数封装相关的知识，希望对你有一定的参考价值。
一、Action生命周期
每次请求到来时，都会创建一个新的Action实例
Action是线程安全的，可以使用成员变量接收参数
二、获取参数的方式（3种）
1.属性驱动获得参数
每次请求Action时都会创建新的Action实例对象
1 public class Demo8Action extends ActionSupport{ 2 //准备与参数键 3 private String name; 4 //自动类型转换 只能转换8大基本数据类型以及对应包装类 5 private Integer age; 6 //支持特定类型字符串转换为Date，例如yyyy-mm-dd 7 private Date birthday; 8 9 public String getName() { 10 return name; 11 } 12 13 public Integer getAge() { 14 return age; 15 } 16 17 public void setAge(Integer age) { 18 this.age = age; 19 } 20 21 public void setName(String name) { 22 this.name = name; 23 } 24 25 @Override 26 public String execute() throws Exception { 27 System.out.println("name参数值:"+name+",age参数值："+age+"生日:"+birthday); 28 return SUCCESS; 29 } 30 31 public Date getBirthday() { 32 return birthday; 33 } 34 35 public void setBirthday(Date birthday) { 36 this.birthday = birthday; 37 } 38 39 }
jsp页面
<%@ 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> <form action="${pageContext.request.contextPath}/Demo8Action"> 用户名:<input type="text" name="name" /><br> 年龄:<input type="text" name="age" /><br> 生日:<input type="text" name="birthday" /><br> <input type="submit" value="提交"> </form> </body> </html>
2.对象驱动获得参数
public class Demo9Action extends ActionSupport { private User user; public User getUser() { return user; } public void setUser(User user) { this.user = user; } @Override public String execute() throws Exception { System.out.println(user); return super.execute(); } }
jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <form action="${pageContext.request.contextPath}/Demo9Action"> 用户名:<input type="text" name="user.name" /><br> 年龄:<input type="text" name="user.age" /><br> 生日:<input type="text" name="user.birthday" /><br> <input type="submit" value="提交"> </form> </body> </html>
3.模型驱动获得参数
第一步实现ModelDriven并规定泛型 重写方法 返回 泛型内容
第二步准备user 成员变量
有一个缺点 只能返回一个对象
public class Demo10Action extends ActionSupport implements ModelDriven<User>{ private User user = new User(); @Override public String execute() throws Exception { System.out.println(user); return super.execute(); } @Override public User getModel() { return user; } }
jsp页面
<%@ 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> <form action="${pageContext.request.contextPath}/Demo10Action"> 用户名:<input type="text" name="name" /><br> 年龄:<input type="text" name="age" /><br> 生日:<input type="text" name="birthday" /><br> <input type="submit" value="提交"> </form> </body> </html>
三、集合类型参数封装
public class Demo11Action extends ActionSupport { //list private List<String> list; //Map private Map<String,String> map; public Map<String, String> getMap() { return map; } public void setMap(Map<String, String> map) { this.map = map; } public List<String> getList() { return list; } public void setList(List<String> list) { this.list = list; } @Override public String execute() throws Exception { System.out.println("map:"+map); System.out.println("list:"+list); return super.execute(); } }
jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <form action="${pageContext.request.contextPath}/Demo11Action" method="post"> list:<input type="text" name="list" /><br> list:<input type="text" name="list[3]" /><br> map:<input type="text" name="map[‘haha‘]" /><br> map:<input type="text" name="map[‘lala‘]" /><br> <input type="submit" value="提交"> </form> </body> </html>
以上是关于Struts2-整理笔记Action生命周期如何获取参数（3种）集合类型参数封装的主要内容，如果未能解决你的问题，请参考以下文章