SpringBoot使用注解的方式统一返回接口结果集

1.创建一个Result类，包含返回的状态码，返回提示消息和数据结果

package com.dyzwj.zwjsharding.entity;

import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;


// 成功结果实体
@Data
public class Result implements Serializable {

    private Integer code;
    private String message;
    private T data;

    public void setResultCode(ResultCode resultCode) {
        this.code = resultCode.code();
    }

    public static Result success() {
        Result result = new Result();
        result.setResultCode(ResultCode.SUCCESS);
        return result;
    }

    public static Result success(T data) {
        Result result = new Result();
        result.setResultCode(ResultCode.SUCCESS);
        result.setCode(ResultCode.SUCCESS.code());
        result.setMessage(ResultCode.SUCCESS.message());
        result.setData(data);
        return result;
    }

    public static Result failure(Integer code, String message) {
        Result result = new Result();
        result.setCode(code);
        result.setMessage(message);
        return result;
    }
}

 2.创建结果状态码枚举类

package com.dyzwj.zwjsharding.entity;


public enum ResultCode {
    
    SUCCESS(1, "成功"),
    SYSTEM_ERROR(400, "系统繁忙，请稍后重试"),
    
    PARAM_IS_INVALID(1001, "参数无效"),
    PARAM_IS_BLANK(1002, "参数为空"),
    PARAM_TYPE_BIND_ERROR(1003, "参数类型错误"),
    PARAM_NOT_COMPLETE(1004, "参数缺失"),
    
    USER_NOT_LOGGED_IN(2001, "用户未登录,访问的路径需要验证,请登录"),
    USER_LOGIN_ERROR(2002, "账号不存在或密码错误"),
    USER_ACCOUNT_FORBIDDEN(2003, "账号已被禁用"),
    USER_NOT_EXIST(2004, "用户不存在"),
    USER_HAS_EXISTED(2005, "用户已存在");

    private Integer code;
    private String message;

    ResultCode(Integer code, String message) {
        this.code = code;
        this.message = message;
    }

    public Integer code() {
        return this.code;
    }

    public String message(){
        return this.message;
    }
}

3.错误结果集

package com.concom.domain;

import lombok.Data;

// 错误结果实体
@Data
public class ErrorResult {
    private Integer code;
    private String message;

    public ErrorResult(Integer code, String message){
        this.code = code;
        this.message = message;
    }
}

4.创建注解类 

package com.dyzwj.zwjsharding.annotation;

import java.lang.annotation.*;

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE,ElementType.METHOD})
@documented
public @interface ResponseResult {
}

5.创建切面类

package com.dyzwj.zwjsharding.aop;

import com.dyzwj.zwjsharding.annotation.ResponseResult;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import java.lang.reflect.Method;

@Aspect
@Component
@Slf4j
public class ResponseResultAop {
    private static final String RESPONSE_RESULT_ANNO = "RESPONSE_RESULT_ANNO";

    //@Around("@within(com.dyzwj.zwjsharding.annotation.ResponseResult)")//这个切点表达式只作用在类上
    @Around("@annotation(com.dyzwj.zwjsharding.annotation.ResponseResult)")//这个切点表达式的作用只用在方法上
    public Object processAop(ProceedingJoinPoint joinPoint)  {
        Object result = null;
        try {
            log.info("开始切入");
            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
            Class clazz = joinPoint.getTarget().getClass();
            MethodSignature signature = (MethodSignature) joinPoint.getSignature();
            Method method = signature.getMethod();
            if (clazz.isAnnotationPresent(ResponseResult.class)) {
                request.setAttribute(RESPONSE_RESULT_ANNO, clazz.getAnnotation(ResponseResult.class));
            }else if (method.isAnnotationPresent(ResponseResult.class)) {
                request.setAttribute(RESPONSE_RESULT_ANNO, method.getAnnotation(ResponseResult.class));
            }
            result = joinPoint.proceed();
            log.info("目标方法执行完成");
        } catch (Throwable e) {
            log.error("切面执行出错,原因是:{}", e);
        }
        return result;
    }
}

6. 写一个类继承ResponseBodyAdvice重写supports()和beforeBodyWrire()方法，该类需要使用@RestControllerAdvice注解和@RestControllerAdvice注解，并将其放入IOC容器交给spring进行管理,这个类就是在将数据返回给DispathchServlet对视图进行渲渲染前对body进行重写，当supports方法返回true的时候，该方法才会去执行beforeBodyWrite()方法，对返回的body进行重写

package com.dyzwj.zwjsharding.handler;

import com.dyzwj.zwjsharding.annotation.ResponseResult;
import com.dyzwj.zwjsharding.entity.ErrorResult;
import com.dyzwj.zwjsharding.entity.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import javax.servlet.http.HttpServletRequest;

@Component
@Slf4j
@RestControllerAdvice
public class ResponseResultAdvice implements ResponseBodyAdvice