最简单全局异常处理

全局异常处理
首先是异常错误码，用接口统一起来

/**
 * 封装API的错误码
 */
public interface IErrorCode {
    long getCode();

    String getMessage();
}

public enum BizExceptionEnum implements IErrorCode {

    /**
     * 业务请求相关异常，基本上是返回给用户的
     */
    INCORRECT_PARAMETER(20000L, "参数不正确"),
    NO_RECORD(20001L, "没有记录,请核对查询条件"),
    PARAMS_INVALID(20003L, "参数:{0}为必传项");


    BizExceptionEnum(Long code, String message) {
        this.code = code;
        this.message = message;
    }

    private Long code;

    private String message;

    public void setCode(Long code) {
        this.code = code;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    @Override
    public long getCode() {
        return code;
    }

    @Override
    public String getMessage() {
        return message;
    }
}
public enum BizExceptionEnum implements IErrorCode {
​
    /**
     * 业务请求相关异常，基本上是返回给用户的
     */
    INCORRECT_PARAMETER(20000L, "参数不正确"),
    NO_RECORD(20001L, "没有记录,请核对查询条件"),
    PARAMS_INVALID(20003L, "参数:{0}为必传项");
​
​
    BizExceptionEnum(Long code, String message) {
        this.code = code;
        this.message = message;
    }
​
    private Long code;
​
    private String message;
​
    public void setCode(Long code) {
        this.code = code;
    }
​
    public void setMessage(String message) {
        this.message = message;
    }
​
    @Override
    public long getCode() {
        return code;
    }
​
    @Override
    public String getMessage() {
        return message;
    }
}

这个错误码不止异常可以用，也可以用来返回

public enum ResultCode implements IErrorCode {
    SUCCESS(200, "操作成功"),
    FAILED(500, "服务器繁忙,请稍后再试"),
    BUSINESS_FAILED(501, "业务异常,具体错误看下级状态码"),
    LIMIT_REQ_FAILED(503, "服务器繁忙,请稍后再试"),
    FAILED_UP_SERVER(505, "上游服务不可用"),
    FAIL_MESSAGE(509, "服务器繁忙,请稍后再试"),
    VALIDATE_FAILED(404, "参数检验失败"),
    UNAUTHORIZED(401, "暂未登录或token已经过期"),
    FORBIDDEN(403, "没有相关权限");
    private long code;
    private String message;
​
    private ResultCode(long code, String message) {
        this.code = code;
        this.message = message;
    }
​
    public long getCode() {
        return code;
    }
​
    public String getMessage() {
        return message;
    }
}

接下来就是自定义异常，很简单
public class BaseException extends RuntimeException {
    private IErrorCode iErrorCode;
​
    public BaseException() {
        super();
    }
​
    public BaseException(IErrorCode exceptionEnum) {
        super(exceptionEnum.getMessage());
        this.iErrorCode=exceptionEnum;
    }
​
    public BaseException(IErrorCode exceptionEnum, Throwable cause) {
        super(exceptionEnum.getMessage(), cause);
        this.iErrorCode=exceptionEnum;
    }
​
    public BaseException(Throwable cause) {
        super(cause);
    }
​
    public static void fail(IErrorCode exceptionEnum) {
        throw new BaseException(exceptionEnum);
​
    }
    /**
     * 断言flag为真，不是真就报错，返回message
     */
    public static void assertTrue(boolean flag, IErrorCode exceptionEnum) {
        if (!flag) {
            fail(exceptionEnum);
        }
    }
​
    /**
     * 断言flag为假，不是false就报错
     */
    public static void assertFalse(boolean flag, IErrorCode exceptionEnum) {
        assertTrue(!flag, exceptionEnum);
    }
    public IErrorCode getiErrorCode() {
        return iErrorCode;
    }
}

里面加个两个断言方法，用起来方便一点。
接下来就是全局异常的控制，也是采用@ControllerAdvice注解

@RestControllerAdvice
@Slf4j
public class GlobalExceptionHandler {
    private static final String PARAM_PREFIX  = "param:{}";
​
    /**
     *自定义异常处理
     * @return
     */
    @ExceptionHandler(ApiException.class)
    public CommonResult exception(HttpServletRequest request,ApiException e){
        log.error(PARAM_PREFIX, request.getRequestURI(), e);
        return CommonResult.failed(e.getMessage());
    }
}

@RestControllerAdvice和@RestController一样，就是@ResponseBody+@ControllerAdvice，不用再单独写了。
that’s all