后端对返回数据的封装

public class Result<T> {

    private int code;
    private String msg;
    private T data;

    public static <T> Result<T> success(T data){
        return new Result<T>(data);
    }
    
    public static <T> Result<T> error(CodeMsg codeMsg){
        return new  Result<T>(codeMsg);
    }
    
    private Result(T data) {
        this.code = 0;
        this.msg = "success";
        this.data = data;
    }
    
    private Result(CodeMsg codeMsg) {
        if(codeMsg == null) {
            return;
        }
        this.code = codeMsg.getCode();
        this.msg = codeMsg.getMsg();
    }

    public int getCode() {
        return code;
    }
    public String getMsg() {
        return msg;
    }
    public T getData() {
        return data;
    }

}

public class CodeMsg {

    private int code;
    private String msg;

    public static CodeMsg SERVER_ERROR = new CodeMsg(500100, "服务端异常");

    private CodeMsg(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }
    
    public int getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }

}

@Controller
@RequestMapping("/demo")
public class DemoController {
    
         @RequestMapping("/hello")
        @ResponseBody
        public Result<String> hello() {
             return Result.success("hello 小老弟");
        }
         
         @RequestMapping("/helloError")
        @ResponseBody
        public Result<String> helloError() {
             return Result.error(CodeMsg.SERVER_ERROR);
        }
         
}