异常分为以下三种

• 自定义异常
• 可预知异常
• 不可预知异常

下面具体说明如何分类处理，从而保证无论触发什么异常均可返回理想的自定义数据格式

ResultCode

/**
 * Created by mrt on 2018/3/5.
 * 10000-- 通用错误代码
 * 22000-- 媒资错误代码
 * 23000-- 用户中心错误代码
 * 24000-- cms错误代码
 * 25000-- 文件系统
 */
public interface ResultCode {
    //操作是否成功,true为成功，false操作失败
    boolean success();
    //操作代码
    int code();
    //提示信息
    String message();

}

ResponseResult

import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@Data
@ToString
@NoArgsConstructor
public class ResponseResult implements Response {

    //操作是否成功
    boolean success = SUCCESS;

    //操作代码
    int code = SUCCESS_CODE;

    //提示信息
    String message;

    public ResponseResult(ResultCode resultCode) {
        this.success = resultCode.success();
        this.code = resultCode.code();
        this.message = resultCode.message();
    }

    public static ResponseResult SUCCESS() {
        return new ResponseResult(CommonCode.SUCCESS);
    }

    public static ResponseResult FAIL() {
        return new ResponseResult(CommonCode.FAIL);
    }

}

自定义异常类

import com.xuecheng.framework.model.response.ResultCode;

/**
 * 自定义异常
 *
 * @author john
 * @date 2019/12/20 - 10:57
 */
public class CustomException extends RuntimeException {
    private ResultCode resultCode;

    public CustomException(ResultCode resultCode) {
        //异常信息为错误代码+异常信息
        super("错误代码：" + resultCode.code() + "错误信息：" + resultCode.message());
        this.resultCode = resultCode;
    }

    public ResultCode getResultCode() {
        return this.resultCode;
    }
}

CommonCode (自定义异常信息返回数据枚举类)

import lombok.ToString;

@ToString
public enum CommonCode implements ResultCode{
    INVALID_METHOD(false,10004,"非法方法！"),
    INVALID_PARAM(false,10003,"非法参数！"),
    SUCCESS(true,10000,"操作成功！"),
    FAIL(false,11111,"操作失败！"),
    UNAUTHENTICATED(false,10001,"此操作需要登陆系统！"),
    UNAUTHORISE(false,10002,"权限不足，无权操作！"),
    SERVER_ERROR(false,99999,"抱歉，系统繁忙，请稍后重试！");
//    private static ImmutableMap<Integer, CommonCode> codes ;
    //操作是否成功
    boolean success;
    //操作代码
    int code;
    //提示信息
    String message;
    private CommonCode(boolean success,int code, String message){
        this.success = success;
        this.code = code;
        this.message = message;
    }

    @Override
    public boolean success() {
        return success;
    }
    @Override
    public int code() {
        return code;
    }

    @Override
    public String message() {
        return message;
    }


}

异常处理（包含自定义异常和不可预见异常和可预见异常）

import com.google.common.collect.ImmutableMap;
import com.xuecheng.framework.model.response.CommonCode;
import com.xuecheng.framework.model.response.ResponseResult;
import com.xuecheng.framework.model.response.ResultCode;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 * @author john
 * @date 2019/12/20 - 11:01
 */
@Slf4j
@ControllerAdvice
public class ExceptionCatch {
    //使用EXCEPTIONS存放异常类型和错误代码的映射，ImmutableMap的特点的一旦创建不可改变，并且线程安全
    private static ImmutableMap<Class<? extends Throwable>, ResultCode> EXCEPTIONS;
    //使用builder来构建一个异常类型和错误代码的异常
    protected static ImmutableMap.Builder<Class<? extends Throwable>, ResultCode> builder =
            ImmutableMap.builder();

    static {
        //在这里加入一些基础的异常类型判断---异常存在非自定义异常
        // 参数异常
        // 请求方法异常
        builder.put(HttpMessageNotReadableException.class, CommonCode.INVALID_PARAM);
        builder.put(HttpRequestMethodNotSupportedException.class, CommonCode.INVALID_METHOD);
    }


    //捕获   CustomException异常
    @ExceptionHandler(CustomException.class)
    @ResponseBody
    public ResponseResult customException(CustomException e) {
        log.error("catch   exception   :   {}\r\nexception:   ", e.getMessage(), e);
        ResultCode resultCode = e.getResultCode();
        return new ResponseResult(resultCode);
    }


    //捕获Exception异常---非自定义异常
    @ResponseBody
    @ExceptionHandler(Exception.class)
    public ResponseResult exception(Exception e) {
        log.error("catch   exception   :   {}\r\nexception:   ", e.getMessage(), e);
        if (EXCEPTIONS == null)
            EXCEPTIONS = builder.build();
        // 查看异常是否被定义返回格式---没有就返回默认错误格式
        final ResultCode resultCode = EXCEPTIONS.get(e.getClass());
        final ResponseResult responseResult;
        if (resultCode != null) {
            responseResult = new ResponseResult(resultCode);
        } else {
            responseResult = new ResponseResult(CommonCode.SERVER_ERROR);
        }
        return responseResult;
    }
}