谈到微服务,必不可免就谈到spring cloud.

笔者正是基于spring cloud架构下的异常处理.

异常,按照业务划分下来,分为三类: 参数校验异常,自定义异常,以及系统异常.

参数校验异常: 通常是缺少参数,参数类型错误,以及相关校验不通过(javax.validation).

通常我们项目一开始,便定义了统一的基础异常类,和统一的错误码.

例如:

• 成功: 2000
• 缺少参数: 5001
• 参数类型错误: 5002
• 参数校验异常: 5003
• 系统异常: 5000

基础异常类:

public abstract class BaseException extends RuntimeException {private String code = ResultCodeConstant.SYSTEM_ERROR;public Result getResult() {return Result.fail(this.code, this.getMessage() != null?this.getMessage():"error");}public BaseException() {}public BaseException(String message) {super(message);}public BaseException(String code, String message) {super(message);this.code = code;}public BaseException(String message, Throwable cause) {super(message, cause);}public BaseException(Throwable cause) {super(cause);}public BaseException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {super(message, cause, enableSuppression, writableStackTrace);}public String getCode() {return this.code;}public void setCode(String code) {this.code = code;}
}

code常量类:

public class ResultCodeConstant {public static final String SUCCESS = "2000";//成功public static final String ARGUMENT_VANISH = "5001";//缺少参数public static final String ARGUMENT_TYPE_MISMATCH = "5002";//类型错误public static final String ARGUMENT_CONSTRAINT_VIOLATION = "5003";//参数校验错误public static final String SYSTEM_ERROR = "5000";
}

对外服务

为了达到对外服务的友好和保密,处理异常时,往往是拦截异常后返回友好结果.

首先约定了对外的结果的封装

public class Result<T> implements Serializable {private String code;private String desc;private T data;public T getData() {return this.data;}public Result(String code, String desc, T data) {this.code = code;this.desc = desc;this.data = data;}public void setData(T data) {this.data = data;}public Result() {}public Result(String code, String desc) {this.code = code;this.desc = desc;}public String getCode() {return this.code;}public void setCode(String code) {this.code = code;}public String getDesc() {return this.desc;}public void setDesc(String desc) {this.desc = desc;}public String toJsonString() {return JSONObject.toJSONString(this, new SerializerFeature[]{SerializerFeature.WriteNullStringAsEmpty, SerializerFeature.WriteDateUseDateFormat});}public static Result okDesc() {return new Result(ResultCodeConstant.SUCCESS, "成功");}public static Result okDesc(String desc) {return new Result(ResultCodeConstant.SUCCESS, desc);}public static Result ok(Object data) {return new Result(ResultCodeConstant.SUCCESS, "", data);}public static Result ok(String desc, Object data) {return new Result(ResultCodeConstant.SUCCESS, desc, data);}public static Result fail() {return new Result(ResultCodeConstant.SYSTEM_ERROR, "error");}public static Result fail(String dsec) {return new Result(ResultCodeConstant.SYSTEM_ERROR, dsec);}public static Result fail(String code, String dsec) {return new Result(code, dsec);}public static Result fail(String code, String dsec, Object data) {return new Result(code, dsec, data);}
}

在spring中,可以通过@ControllerAdvice来拦截controller中抛出的异常

/*** Created by wenshiliang on 2017/1/16.*/
@ControllerAdvice()
@ConfigurationProperties
@Slf4j
public class GlobalExceptionHandler {@Autowiredprivate CounterService counterService;public GlobalExceptionHandler() {log.info("GlobalExceptionHandler构建");}@ExceptionHandler(BaseException.class)@ResponseBodypublic Result baseExceptionHandler(BaseException e, HttpServletResponse response) {log.error("拦截自定义异常", e);counterService.increment("exception.custom");return e.getResult();}@ExceptionHandler(MissingServletRequestParameterException.class)@ResponseBodypublic Result missingServletRequestParameterExceptionHandler(MissingServletRequestParameterException e,HttpServletResponse response) {log.warn("缺少参数", e);counterService.increment("exception.check");return Result.fail(ResultCodeConstant.ARGUMENT_VANISH,"缺少参数");}@ExceptionHandler(MethodArgumentTypeMismatchException.class)@ResponseBodypublic Result methodArgumentTypeMismatchExceptionExceptionHandler(MethodArgumentTypeMismatchException e,HttpServletResponse response) {log.warn("参数类型不正确", e);counterService.increment("exception.check");return Result.fail(ResultCodeConstant.ARGUMENT_TYPE_MISMATCH,"参数类型不正确");}/*** 参数校验异常** @param e* @param response* @return*/@ExceptionHandler(ConstraintViolationException.class)@ResponseBodypublic Result constraintViolationExceptionHandler(ConstraintViolationException e, HttpServletResponse response) {log.warn("参数校验异常", e);StringBuilder builder = new StringBuilder();Set<ConstraintViolation<?>> set = e.getConstraintViolations();if (set != null && set.size() > 0) {set.forEach(active -> {log.warn(active.getRootBeanClass() + active.getMessage());builder.append(active.getMessage()).append(".");});} else {builder.append("参数校验异常");}counterService.increment("exception.check");return Result.fail(ResultCodeConstant.ARGUMENT_CONSTRAINT_VIOLATION,builder.toString());}@ExceptionHandler(BindException.class)@ResponseBodypublic Result BindException(BindException e, HttpServletResponse response) {log.warn("参数校验异常", e);counterService.increment("exception.check");String desc = e.getBindingResult().getFieldError().getDefaultMessage();return Result.fail(ResultCodeConstant.ARGUMENT_CONSTRAINT_VIOLATION, desc);}@ExceptionHandler//处理其他异常@ResponseBody //public Result exceptionHandler(Exception e, HttpServletResponse response) {Result result = null;log.error("拦截异常", e);counterService.increment("exception.system");result = Result.fail();return result;}
}

##对内服务