3.Spring MVC 4.1-@RequestMapping

2.1 @RequestMapping

• @RequestMapping是SpringMVC的核心注解,负责访问的url与调用方法之间的映射;
• @RequestMapping可以放在类和方法上;
  • @RequestMapping的属性produces属性控制response返回的形式;
  • @RequestMapping的属性method属性控制接受访问的类型,不写不做限制,本例为演示方便全部都是get请求;
• @ResponseBody(放在方法上或者返回值类型前)将方法参数放置在web body的body中(返回的不是页面而是你所控制的字符)
• @RequestBody(放在方法参数前)将方法参数放置在web request的body中(如提交一个json对象作为参数-在03点睛Spring MVC 4.1-REST演示)
• produces的内容是指定返回的媒体类型让浏览器识别
  • 如返回text/plain的话,chrome浏览器下network显示Response的Content-Type:text/plain;
  • 如返回application/json的话,chrome浏览器下network显示Response的application/json;
  • 因本节无页面,在03点睛Spring MVC 4.1-REST有只管的阐述和演示;
• 这节使用@RequestMapping演示常用映射场景

2.2 演示

• 传值对象

package com.wisely.web;public class DemoObj {    private Long id;    private String name;    public DemoObj() {        super();    }    public DemoObj(Long id, String name) {        super();        this.id = id;        this.name = name;    }    public Long getId() {        return id;    }    public void setId(Long id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

• 控制器 TestController

package com.wisely.web;import javax.servlet.http.HttpServletRequest;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.ResponseBody;@Controller //声明为控制器bean@RequestMapping("/test")// 根地址为http://localhost:8080/testSpringMVC/testpublic class TestController {    //response媒体类型(MediaType)为text/plain,编码是utf-8    @RequestMapping(produces = "text/plain;charset=UTF-8")    //映射地址为http://localhost:8080/testSpringMVC/test    @ResponseBody //此注解让返回值不是页面,也是将结果字符串直接返回    public  String root(HttpServletRequest request){        return "url:"+request.getRequestURL()+" 可以访问此方法";    }    @RequestMapping(value = "/add",produces = "text/plain;charset=UTF-8")    //映射地址为http://localhost:8080/testSpringMVC/test/add    @ResponseBody    public   String add(HttpServletRequest request){        return "url:"+request.getRequestURL()+" 可以访问此方法";    }    @RequestMapping(value = {"/remove","/delete"},produces = "text/plain;charset=UTF-8")    //映射地址为http://.../test/remove(或http://.../test/delete)    @ResponseBody    public   String remove(HttpServletRequest request){        return "url:"+request.getRequestURL()+" 可以访问此方法";    }    //获取request参数    //获取路径参数    @RequestMapping(value = "/get",produces = "text/plain;charset=UTF-8")    //映射路径http://.../test/get?id=123    @ResponseBody    public String passRequestParam(@RequestParam Long id,HttpServletRequest request){        System.out.println("id为"+id);        return "url:"+request.getRequestURL()+" 可以访问此方法";    }    //获取路径参数    @RequestMapping(value = "/{id}",produces = "text/plain;charset=UTF-8")    //映射路径http://.../test/123    @ResponseBody    public String passPathVariable(@PathVariable Long id,HttpServletRequest request){        System.out.println("id为"+id);        return "url:"+request.getRequestURL()+" 可以访问此方法";    }    //获得对象    @RequestMapping(value = "/pass",produces = "text/plain;charset=UTF-8")    //映射路径http://.../test/pass?id=123&name=wyf    @ResponseBody    public String passObj(DemoObj obj,HttpServletRequest request){        System.out.println("对象的id和名称分别为为："+obj.getId()+"/"+obj.getName());        return "url:"+request.getRequestURL()+" 可以访问此方法";    }}