SpringBoot: Unified JSON information return

There are several types of return results after calling the back-end service, such as String Integer Boolean List Map etc., and in one project, in order to maintain consistency, our method return results can all use JSON data format, as follows:

{
    "code":200,
    "msg":"成功",
    "data":"JSON数据"
}

code is the status code corresponding to the results of this request processing, msg is the interpretation information corresponding to the status code, data is the content of the data to be returned, can be any one of the objects.

Encapsulates the response information object

public class ResponseEntity<T> implements Serializable {


    private static final long serialVersionUID = 3595741978061989861L;
    private Integer code;//状态码
    private String msg;//状态码对应信息
    private T data;//要返回的数据


    public Integer getCode() {
        return code;
    }


    public void setCode(Integer code) {
        this.code = code;
    }


    public String getMsg() {
        return msg;
    }


    public void setMsg(String msg) {
        this.msg = msg;
    }


    public T getData() {
        return data;
    }


    public void setData(T data) {
        this.data = data;
    }
}

There are several states, Http request status codes, and are enumerated, as in the following example:

public enum ResponseEnum {


    SUCCESS(200, "成功"),
    FAIL(-1, "失败"),
    ERROR_400(400, "错误的请求"),
    ERROR_404(404, "访问资源不存在"),
    ERROR_500(500, "服务器异常");


    private Integer code;
    private String msg;


    ResponseEnum(Integer code, String msg) {
        this.code = code;
        this.msg = msg;
    }


    public Integer getCode() {
        return code;
    }


    public void setCode(Integer code) {
        this.code = code;
    }


    public String getMsg() {
        return msg;
    }


    public void setMsg(String msg) {
        this.msg = msg;
    }
}

Create a public class to generate a response object

public class ResponseUtil {


    /**
     * 成功返回
     * @param object 返回数据
     * @return
     */
    public static ResponseEntity success(Object object){
        ResponseEntity resp = new ResponseEntity();
        resp.setCode(ResponseEnum.SUCCESS.getCode());
        resp.setMsg(ResponseEnum.SUCCESS.getMsg());
        resp.setData(object);
        return resp;
    }


    /**
     * 成功返回  无数据
     * @return
     */
    public static ResponseEntity success(){
        return success(null);
    }


    /**
     * 失败返回
     * @param responseEnum 响应标识
     * @return
     */
    public static ResponseEntity error(ResponseEnum responseEnum){
        ResponseEntity resp = new ResponseEntity();
        resp.setCode(responseEnum.getCode());
        resp.setMsg(responseEnum.getMsg());
        return resp;
    }
}

Controllers in Spring can be declared with @Controller and @RestController annotations, where @Controller identifies that the current controller is SpringMvc controller and needs to be used in conjunction with @ResponseBody annotations to return JSON object data; @RestController is primarily used to build Restful interface that returns request data from the client, equivalent to using @Controller and @ResponseBody annotations.

(Recommended course: Spring tutorial)

Create a Pojo package and the corresponding entity class

public class DemoEntity {


    private Integer id;
    private String name;


    public Integer getId() {
        return id;
    }


    public void setId(Integer id) {
        this.id = id;
    }


    public String getName() {
        return name;
    }


    public void setName(String name) {
        this.name = name;
    }
}

Create a controller

@Controller

@Controller
public class DemoController {


    @RequestMapping(value = "/users", method= RequestMethod.GET)
    @ResponseBody
    public ResponseEntity users(){
        List<DemoEntity> list = new ArrayList<DemoEntity>();
        DemoEntity demo = new DemoEntity();
        demo.setId(1);
        demo.setName("蜗牛");
        list.add(demo);
        DemoEntity demo1 = new DemoEntity();
        demo1.setId(2);
        demo1.setName("葡萄");
        list.add(demo1);
        return ResponseUtil.success(list);
    }
}

Test: After you start the service, enter http://localhost:8080/users in the browser address bar and you can see the output on the page

{"code":200,"msg":"成功","data":[{"id":1,"name":"蜗牛"},{"id":2,"name":"葡萄"}]}

@RestController

@RestController
public class DemoRestController {


    @RequestMapping(value = "/users1", method= RequestMethod.GET)
    public ResponseEntity users(){
        List<DemoEntity> list = new ArrayList<DemoEntity>();
        DemoEntity demo = new DemoEntity();
        demo.setId(1);
        demo.setName("蜗牛");
        list.add(demo);
        DemoEntity demo1 = new DemoEntity();
        demo1.setId(2);
        demo1.setName("葡萄");
        list.add(demo1);
        return ResponseUtil.success(list);
    }
}

You can also see the results above after the request.

(Recommended tutorial: Spring Boot those things.) )

The above is about SpringBoot: Unified JSON information return related to the introduction, I hope to help you.