springboot 统一异常处理；统一返回结果处理

        自己封装的一个springboot 接口框架，使用springboot+mybatis，开箱即用使用，互相交流。地址：https://gitee.com/xiaokd/springboot-demo

我项目中使用了lombok，请大家先配置好lombok插件

1. 定义一个父级枚举接口（所有异常枚举类实现此接口）

package com.lwk.springbootdemo.common.exception;


public interface SuperEnumFace {
    
    public int getCode();

    
    public String getMessage();
}

2. 定义一个基本异常类 （注意自定义的异常类类要继承 RuntimeException，因为spring默认抛出运行时异常事务才会自动回滚）

package com.lwk.springbootdemo.common.exception;

import lombok.AllArgsConstructor;
import lombok.Getter;


@Getter
@AllArgsConstructor
public class BaseException extends RuntimeException{
    private int code;
    private String message;

    
    public BaseException(SuperEnumFace superEnumFace){
        this.code = superEnumFace.getCode();
        this.message = superEnumFace.getMessage();
    }
}

3. 定义一个异常枚举

package com.lwk.springbootdemo.common.exception;

import lombok.AllArgsConstructor;


@AllArgsConstructor
public enum BaseExceptionEnum implements SuperEnumFace{

    SUCESS(20000, "操作成功"),
    FAIL(40000, "操作失败"),
    ERROR(50000, "服务器异常，请稍后重试"),
    LOGIN_EXPIRE(60000, "登录状态过期，请重新登陆")
    ;

    private int code;
    private String message;

    @Override
    public int getCode() {
        return this.code;
    }

    @Override
    public String getMessage() {
        return this.message;
    }
}

4. 定义一个结果类 

package com.lwk.springbootdemo.common.repo;

import com.lwk.springbootdemo.common.exception.BaseExceptionEnum;
import com.lwk.springbootdemo.common.exception.SuperEnumFace;
import lombok.AllArgsConstructor;
import lombok.Data;
import org.springframework.util.ObjectUtils;

import java.io.Serializable;


@Data
@AllArgsConstructor
public class Result implements Serializable {
    
    private int code;
    
    private String message;
    
    private T data;

    public Result(int code, String message){
        this.code = code;
        this.message = message;
    }

    public Result(SuperEnumFace superEnumFace){
        this.code = superEnumFace.getCode();
        this.message = superEnumFace.getMessage();
    }

    public Result(SuperEnumFace superEnumFace, T data){
        this.code = superEnumFace.getCode();
        this.message = superEnumFace.getMessage();
        this.data = data;
    }

    
    public static Result error(String message){
        if(ObjectUtils.isEmpty(message)){
            return new Result(BaseExceptionEnum.ERROR);
        }else {
            return new Result(BaseExceptionEnum.ERROR.getCode(), message);
        }
    }

    
    public static  Result success(T data){
        return new Result(BaseExceptionEnum.SUCESS, data);
    }
}

5. 定义统一异常处理类

package com.lwk.springbootdemo.common.advice;

import com.lwk.springbootdemo.common.exception.BaseException;
import com.lwk.springbootdemo.common.repo.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestControllerAdvice;


@Slf4j
@RestControllerAdvice
public class ExceptionHandlerAdvice {

    
    @ExceptionHandler(value = BaseException.class)
    @ResponseBody
    public Result exceptionHandler(BaseException baseException){
        log.error("业务异常：{}", baseException.getMessage());
        return Result.error(baseException.getMessage());
    }

    
    public Result exceptionHandler(Exception exception){
        log.error("运行时异常：{}", exception.getMessage());
        return Result.error(null);
    }
}

6. 定义统一结果处理类（string类型要单独进行处理）

package com.lwk.springbootdemo.common.advice;

import com.alibaba.fastjson.JSON;
import com.lwk.springbootdemo.common.repo.Result;
import lombok.SneakyThrows;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;


@RestControllerAdvice
public class ResponseAdvice implements ResponseBodyAdvice {

    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        return !returnType.getGenericParameterType().equals(Result.class);
    }

    @SneakyThrows
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        if(returnType.getGenericParameterType().equals(String.class)){ //返回string类型
            return JSON.toJSONString(Result.success(body));
        }else if(body == null){ //返回void
            return Result.success(null);
        }else {
            return Result.success(body);
        }
    }
}

7. 抛出异常，查看返回结果

package com.lwk.springbootdemo.service.impl;

import com.lwk.springbootdemo.common.exception.BaseException;
import com.lwk.springbootdemo.common.exception.BaseExceptionEnum;
import com.lwk.springbootdemo.entity.Dept;
import com.lwk.springbootdemo.mapper.DeptMapper;
import com.lwk.springbootdemo.service.DeptService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;


@Service
public class DeptServiceImpl implements DeptService {
    @Resource
    private DeptMapper deptMapper;

    @Override
    public List getDepts(int id) {
        if(id == 0){
            throw new BaseException(BaseExceptionEnum.ERROR);
        }
        List depts = deptMapper.getDetps();
        return depts;
    }
}

8. 结果显示：参数传1，正确返回数据；参数传0，抛出异常

9. 收工