详解SpringBoot如何实现统一后端返回格式

@GetMapping("/hello")
public String hello() {
    return  "hello";
}

@GetMapping("/student")
public Student getStudent() {
        Student student = new Student();
        student.setId(1);
        student.setName("didiplus");
        return  student;
}


//student的类
@Data
public class Student {
    private Integer id;
    private String name;
}

@GetMapping("/error")
public int error(){
    int i = 9/0;
    return i;
}

package com.didiplus.common.WEB.response;

import lombok.Data;

import java.io.Serializable;



@Data
public class Result<T> implements Serializable {

    
    private boolean success;

    
    private int code;

    
    private String msg;

    
    private T data;

    
    private long timestamp ;


    public Result (){
        this.timestamp = System.currentTimeMillis();
    }
    
    public static <T> Result<T> success() {
        return  success(null);
    }

    
    public static <T> Result<T> success(T data){
        return success(ResultCode.RC100.getMessage(),data);
    }

    
    public static <T> Result<T> success(String message) {
        return success(message, null);
    }

        
    public static <T> Result<T> success(String message, T data) {
        return success(ResultCode.RC100.getCode(), message, data);
    }

    
    public static <T> Result<T> success(int code, String message) {
        return success(code, message, null);
    }

    public static <T> Result<T> success(int code,String message,T data) {
        Result<T> result = new Result<T>();
        result.setCode(code);
        result.setMsg(message);
        result.setSuccess(true);
        result.setData(data);
        return result;
    }

    
    public static <T> Result<T> failure() {
        return failure(ResultCode.RC100.getMessage());
    }

    
    public static <T> Result<T> failure(String message) {
        return failure(message, null);
    }

    
    public static <T> Result<T> failure(String message, T data) {
        return failure(ResultCode.RC999.getCode(), message, data);
    }

    
    public static <T> Result<T> failure(int code, String message) {
        return failure(ResultCode.RC999.getCode(), message, null);
    }

    
    public static <T> Result<T> failure(int code, String message, T data) {
        Result<T> result = new Result<T>();
        result.setCode(code);
        result.setMsg(message);
        result.setSuccess(false);
        result.setData(data);
        return result;
    }

    
    public static <T> Result<T> decide(boolean b) {
        return decide(b, ResultCode.RC100.getMessage(), ResultCode.RC999.getMessage());
    }

    
    public static <T> Result<T> decide(boolean b, String success, String failure) {
        if (b) {
            return success(success);
        } else {
            return failure(failure);
        }
    }
}

package com.didiplus.common.web.response;

import lombok.Getter;


public enum ResultCode {
    
    RC100(100,"操作成功"),
    
    RC999(999,"操作失败"),
    
    RC200(200,"服务开启限流保护,请稍后再试!"),
    
    RC201(201,"服务开启降级保护,请稍后再试!"),
    
    RC202(202,"热点参数限流,请稍后再试!"),
    
    RC203(203,"系统规则不满足要求,请稍后再试!"),
    
    RC204(204,"授权规则不通过,请稍后再试!"),
    
    RC403(403,"无访问权限,请联系管理员授予权限"),
    
    RC401(401,"匿名用户访问无权限资源时的异常"),
    
    RC500(500,"系统异常，请稍后重试"),

    INVALID_TOKEN(2001,"访问令牌不合法"),
    ACCESS_DENIED(2003,"没有权限访问该资源"),
    CLIENT_AUTHENTICATION_FAILED(1001,"客户端认证失败"),
    USERNAME_OR_PASSWord_ERROR(1002,"用户名或密码错误"),
    UNSUPPORTED_GRANT_TYPE(1003, "不支持的认证模式");

    
    @Getter
    private final int code;

    
    @Getter
    private final String message;
    
    ResultCode(int code, String message) {

        this.code = code;

        this.message = message;
    }
}

    @GetMapping("/hello")
    public Result<String> hello() {
        return  Result.success("操作成功","hello");
    }

public interface ResponseBodyAdvice<T> {
		
    boolean supports(MethodParameter var1, Class<? extends HttpMessageConverter<?>> var2);

	  
    @Nullable
    T beforeBodyWrite(@Nullable T var1, MethodParameter var2, MediaType var3, Class<? extends HttpMessageConverter<?>> var4, ServerHttpRequest var5, ServerHttpResponse var6);
}

@RestControllerAdvice
public class ResponseAdvice  implements ResponseBodyAdvice<Object> {


    @Autowired
    ObjectMapper objectMapper;

    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return true;
    }

    @SneakyThrows
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response)  {
        if (body instanceof  String){
            return objectMapper.writeValueAsString(Result.success(ResultCode.RC100.getMessage(),body));
        }
        return Result.success(ResultCode.RC100.getMessage(),body);
    }
}

        if (body instanceof  String){
            return objectMapper.writeValueAsString(Result.success(ResultCode.RC100.getMessage(),body));
        }

    @GetMapping("/hello")
    public String hello() {
        return "hello,didiplus";
    }


    @GetMapping("/student")
    public Student getStudent() {
        Student student = new Student();
        student.setId(1);
        student.setName("didiplus");
        return student;
    }