SpringMVC之@RequestBody

╰+攻爆jí腚メ 2022-05-17 08:23 153阅读 0赞

# @RequestBody #

因为一直觉得传简单对象直接不用注解也可以自动组装，就以为Spring可以为我们组装所有类型的对象。但今天测试过，原来象Map，List或复合对象都必需使用这个注解才可以正确组装，以下是我的测试代码：

首先写个测试的Controller：

import java.util.List;
    import java.util.Map;
    
    import javax.servlet.http.HttpServletResponse;
    
    import org.cunframework.core.common.controller.BaseController;
    import org.springframework.context.annotation.Scope;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.CrossOrigin;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.alibaba.fastjson.JSON;
    
    class A{
        private String name;
        private String value;
        public String getName() {
            return name;
        }
        public String getValue() {
            return value;
        }
        public void setName(String name) {
            this.name = name;
        }
        public void setValue(String value) {
            this.value = value;
        }
    }
    
    class B{
        private List<A> a;
        private String count;
    
        public List<A> getA() {
            return a;
        }
        public String getCount() {
            return count;
        }
        public void setA(List<A> a) {
            this.a = a;
        }
        public void setCount(String count) {
            this.count = count;
        }
    }
    
    @Scope("prototype")
    @Controller
    @RequestMapping("/rb")
    
    public class RequestBodyController extends BaseController{ 
    
        @RequestMapping(value = "test1")
        @ResponseBody
        public Map test1(A a,HttpServletResponse response) {
    
            try {
                System.out.println(JSON.toJSONString(a));
                return toSuccess();
            } catch (Exception e) {
                e.printStackTrace();
                return toError();
            }
        }
    
        @RequestMapping(value = "test2")
        @ResponseBody
        public Map test2(List<A> a,HttpServletResponse response) {
            try {
                System.out.println(JSON.toJSONString(a));
                return toSuccess();
            } catch (Exception e) {
                e.printStackTrace();
                return toError();
            }
        }
    
        @RequestMapping(value = "test3")
        @ResponseBody
        public Map test3(@RequestBody List<A> a,HttpServletResponse response) {
            try {
                System.out.println(JSON.toJSONString(a));
                return toSuccess();
            } catch (Exception e) {
                e.printStackTrace();
                return toError();
            }
        }
    
        @RequestMapping(value = "test4")
        @ResponseBody
        public Map test4(B b,HttpServletResponse response) {
            try {
                System.out.println(JSON.toJSONString(b));
                return toSuccess();
            } catch (Exception e) {
                e.printStackTrace();
                return toError();
            }
        }
    
        @RequestMapping(value = "test5")
        @ResponseBody
        public Map test5(@RequestBody B b,HttpServletResponse response) {
            try {
                System.out.println(JSON.toJSONString(b));
                return toSuccess();
            } catch (Exception e) {
                e.printStackTrace();
                return toError();
            }
        }
    }

测试用的html文件：

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Document</title>
        <script src="http://lib.sinaapp.com/js/jquery/1.9.1/jquery-1.9.1.min.js"></script>
        <script> function ajax(url,data,contentType){ $.ajax({ type: "POST", contentType: contentType, url: url, data: data, success: function(data){ console.log(data); }, error: function(XMLHttpRequest, textStatus, errorThrown) { alert("Error Occured!"); } }); } function test1(){ var data = { name:123, value:456 }; ajax( "http://localhost:8080/orcs/rb/test1.do", data, "application/x-www-form-urlencoded" ) } function test2(){ var data = [ { name:123, value:456 }, { name:222, value:222 }, { name:333, value:444456 } ]; ajax( "http://localhost:8080/orcs/rb/test2.do", data, "application/x-www-form-urlencoded" ); } function test3(){ var data = [ { name:123, value:456 }, { name:222, value:222 }, { name:333, value:444456 } ]; ajax( "http://localhost:8080/orcs/rb/test3.do", JSON.stringify(data), "application/json" ); } function test4(){ var data = { a:[{ name:123, value:456 }, { name:222, value:222 }, { name:333, value:444456 }], count:222 } ajax( "http://localhost:8080/orcs/rb/test4.do", data, "application/x-www-form-urlencoded" ); } function test5(){ var data = { a:[{ name:123, value:456 }, { name:222, value:222 }, { name:333, value:444456 }], count:222 }; ajax( "http://localhost:8080/orcs/rb/test5.do", JSON.stringify(data), "application/json" ); } </script>
    </head>
    <body>
        <button onclick="test1()">btn1</button>
        <button onclick="test2()">btn2</button>
        <button onclick="test3()">btn3</button>
        <button onclick="test4()">btn4</button>
        <button onclick="test5()">btn5</button>
    </body>
    </html>

发现`@RequestBody`这个注解，使用时对`ajax`有些要求：

*  数据必需要用`JSON.stringify(data)`处理
 *  contentType类型必需为`application/json`

而不加这个，注解组装简单对象时，则：

*  数据直接用json，不必处理
 *  contentType类型默认为`application/x-www-form-urlencoded`即可

> 转载自[《Spring MVC 解决跨域问题&以及对@RequestBody的理解》][Spring MVC _RequestBody]

[Spring MVC _RequestBody]: https://blog.csdn.net/wq_static/article/details/51418384