数据的处理

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1、提交数据的处理

a：提交的域名称和处理方法的参数名一致

提交的数据：http://localhost:8080/spring_data/hello.do?name=allen

处理方法：

HelloController：

package controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;@Controllerpublic class HelloController {public HelloController() {System.out.println("hello controller");}@RequestMapping("/hello")public String hello(String name) {// 重定向：System.out.println(name);return "index.jsp";}}

b：如果域名称和参数名不一致

http://localhost:8080/spring_data/hello.do?uname=allen

HelloController.java

package controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;@Controllerpublic class HelloController {public HelloController() {System.out.println("hello controller");}//uname是提交的域名称@RequestMapping("/hello")public String hello(@RequestParam("uname")String name) {// 重定向：System.out.println(name);return "index.jsp";}}

c：提交的是一个对象

要求提交的表单域名和对象的属性名一致，参数使用对象即可

http://localhost:8080/spring_data/user.do?name=leijun&age=48

处理方法：

package controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import cn.sxt.vo.User;@Controllerpublic class HelloController {public HelloController() {System.out.println("hello controller");}@RequestMapping("/user")public String user(User user) {System.out.println(user);return "user.jsp";}}

实体类：User.java

package cn.sxt.vo;import java.util.Date;import org.springframework.format.annotation.DateTimeFormat;public class User {private String name;private int age;@DateTimeFormat(pattern="yyyy-MM-dd")private Date birthday;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 getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}@Overridepublic String toString() {return "User [name=" + name + ", age=" + age + "]";}}

2、将数据显示到UI层

第一种通过ModelAndView---需要视图解析器：

package springmvc.controller;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.mvc.Controller;public class HelloController implements Controller {@Overridepublic ModelAndView handleRequest(HttpServletRequest arg0,HttpServletResponse arg1) throws Exception { ModelAndView mv = new ModelAndView();

//相当于req.setAttribute("msg","hello spring mvc");mv.addObject("msg", "hello springmvc controller");mv.setViewName("hello");return mv;}}

第二种：通过ModelMap来实现，不需要视图解析器

需要作为处理方法的参数

@RequestMapping("/hello")public String hello(@RequestParam("uname") String name,ModelMap model) {// 相当于request.setAttribute("name",name);model.addAttribute("name","name");System.out.println(name);return "index.jsp";}

ModelAndView和ModelMap的区别：

相同点：都可以将数据封装显示在UI层

不同点：ModelAndView可以指定跳转的视图，ModelMap不能

ModelAndView需要视图解析器，ModelMap不需要

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