SpringMVC的学习____4.前端,控制器参数名不一致以及对象传递的解决方法
代码如下:
1.SpringMVC的web.xml文件:(DispatcherServlet配置)
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc-servlet.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
2.SpringMVC的配置文件 (springmvc-servlet.xml)
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!--包的自动扫描--> <context:component-scan base-package="com.xbf.controller"/> <!--静态资源过滤 SpringMVC不处理静态资源--> <mvc:default-servlet-handler/> <!--注解驱动--> <mvc:annotation-driven/> <!--视图解析器--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean> </beans>
3.Controller层的编写:
package com.xbf.controller; import com.xbf.pojo.User; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; @Controller public class UserController { @RequestMapping("/t1/{name}") //restful风格 //前端请求参数名和处理的参数名一致时 //可以直接拿过来用 //String name就是前端请求的参数名 public String test1(@PathVariable String name, Model model){ model.addAttribute("aaa",name); return "user"; } @RequestMapping("/t2") //前端传递过来的参数名和控制器进行处理的参数名不一致时 //使用 @RequestPara 注解进行解释说明 // username:前端传递过来的参数名 // name:控制器进行处理的参数名 public String test2(@RequestParam(value = "username") String name,Model model){ model.addAttribute("aaa",name); return "user"; } @RequestMapping("/t3") //研究对象的传递 //使用set方法给属性设置值,若没有传值就为默认值,设值前判断属性名是否一致呢??? //会将前端传递过来的对象属性属性值对自动封装成对象 (user) public String test3(User user,Model model){ System.out.println(user); model.addAttribute("user",user); return "user"; } @RequestMapping("/t333/{id}/{name}/{age}") //restful风格 public String test33(User user,Model model){ System.out.println(user); model.addAttribute("user",user); return "user"; } @RequestMapping("/t33/{id}/{name}/{age}") //restful风格 public String test33(@PathVariable int id,@PathVariable String name,@PathVariable int age,Model model){ User user = new User(); user.setName(name); user.setId(id); user.setAge(age); System.out.println(user); model.addAttribute("user",user); return "user"; } }
4.前端页面 (user.jsp)
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> ${aaa} <hr> <p> 姓名:${user.getName()} ID:${user.getId()} 年龄:${user.getAge()} </p> </body> </html>
pojo实体类:
package com.xbf.pojo; public class User { private int id; private String name; private int age; public User() { } public User(int id, String name, int age) { this.id = id; this.name = name; this.age = age; } public int getId() { return id; } public void setId(int 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 "User{" + "id=" + id + ", name='" + name + '\'' + ", age=" + age + '}'; } }
总结: DispatcherServlet将拦截的前端请求分发给某个具体的控制器,由控制器进行模型数据处理并返回。