3 rest

原创地址:http://wiselyman.iteye.com/blog/2214290

3.1 REST

• REST:Representational State Transfer;
• REST是一种数据导向web service,相对于SOAP是一种操作操作和处理导向的web service;
• Spring为对REST的支持提供了@RestController;
  • 在没有@RestController可以通过@Controller,@ResponseBody组合实现REST控制器;
  • 但是我们经常会使用@ResponseBody这样很麻烦,且易忘记;
  • 使用@RestController替代@Controller,我们就不用使用@ResponseBody;
• REST支持的http method(通过@RequestMapping的method属性控制)
  • POST:新增
  • GET:读取
  • PUT/PATCH:更新
  • DELETE:删除

• 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,浏览器上的js回掉拿到的是字符串,需要自己转换对象;
  • 如返回application/json的话,浏览器上的js拿到的就是js对象而不是字符串,就不需要进行转换;

• 本例演示向控制器提交json数据,返回结果分别为json和xml格式;

3.2 示例

3.2.1 @RestController源码

从@RestController看出,@RestController是一个元注解,组合了@Controller,@ResponseBody,相当于同时使用了@Controller @ResponseBody

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Controller@ResponseBodypublic @interface RestController {    /**     * The value may indicate a suggestion for a logical component name,     * to be turned into a Spring bean in case of an autodetected component.     * @return the suggested component name, if any     * @since 4.0.1     */    String value() default "";}

3.2.2 代码

• 添加jackson依赖

jackson-dataformat-xml依赖jackson-bind,这样我们能同时返回xml和json

<dependency>    <groupId>com.fasterxml.jackson.dataformat</groupId>    <artifactId>jackson-dataformat-xml</artifactId>    <version>2.5.3</version></dependency>

若只需返回json数据(大多数项目都是这样),将上面依赖更换为

 <dependency>    <groupId>com.fasterxml.jackson.core</groupId>    <artifactId>jackson-databind</artifactId>    <version>2.5.3</version></dependency>

• 传值对象

package com.wisely.web;public class DemoObj {    private Long id;    private String name;    //此处一定要有空构造,不然会有400 bad request,主要是jackson将json参数转换为对象需要    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;    }}

• DemoMVCConfig注册静态资源

    // 静态资源映射    @Override    public void addResourceHandlers(ResourceHandlerRegistry registry) {        registry.addResourceHandler("/js/**").addResourceLocations("/js/");    }

• 控制器

package com.wisely.web;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestController@RequestMapping("/api")public class RESTController {    @RequestMapping(value = "/getjson",produces={"application/json;charset=UTF-8"})    public DemoObj getjson(@RequestBody DemoObj obj){        return new DemoObj(obj.getId()+1, obj.getName()+"yy");    }    @RequestMapping(value = "/getxml",produces={"application/xml;charset=UTF-8"})    public DemoObj getxml(@RequestBody DemoObj obj){        return new DemoObj(obj.getId()+1, obj.getName()+"yy");    }}

• 页面代码

<script type="text/javascript" src="<c:url value="/js/jquery.js" />"></script><script type="text/javascript">var json = {"id":456,"name":"phy"};$.ajax({      url: "api/getjson",      data: JSON.stringify(json),      type:"POST",      contentType:"application/json",      success: function(data){          console.log(data);      }    });$.ajax({      url: "api/getxml",      data: JSON.stringify(json),      type:"POST",      contentType:"application/json",      success: function(data){          console.log(data);      }    });</script>

• 结果