此系列文章将会描述Java框架Spring Boot、服务治理框架Dubbo、应用容器引擎Docker，及使用Spring Boot集成Dubbo、Mybatis等开源框架，其中穿插着Spring Boot中日志切面等技术的实现，然后通过gitlab-CI以持续集成为Docker镜像。
本文为Spring Boot使用@ControllerAdvice进行自定义异常捕捉及处理
本系列文章中所使用的框架版本为Spring Boot 2.0.3-RELEASE，Spring 5.0.7-RELEASE，Dubbo 2.6.2。
注解
@ControllerAdvice
控制器增强，所有在Controller中被抛出的异常将会被使用@ControllerAdvice注解的类捕捉。默认情况下， @ControllerAdvice全局应用于所有控制器的方法。
若所有异常处理类返回的数据格式为
json，则可以使用@RestControllerAdvice代替@ControllerAdvice@RestControllerAdvice = @ControllerAdvice + @ResponseBody
@ExceptionHandler
异常处理器，在特定异常处理程序的类或方法中以处理异常的注解。
业务异常
常规的Controller层，会抛出业务异常、校检异常等
@RestController
@RequestMapping(value = "/")
public class TestController {
@Autowired
private BussinessService bussinessService ;
@RequestMapping(value = "/basic", method = RequestMethod.POST)
public Resp<RespVO> getBasic(@RequestBody @Valid ReqVO reqVO) {
RespVO respVO = bussinessService.getResult(reqVO);
if（respVO == null）
throws BussinessExceptionMapper.build("调用失败");
return Resp.createSuccess(respVO);
}
}
业务异常定义
@Setter
@Getter
public class BussinessException extends RuntimeException {
public static final String UNKNOWN_EXCEPTION = "unknown.exception";
public static final String SERVICE_FAIL = "service.fail";
public static final String NETWORK_EXCEPTION = "network.exception";
public static final String TIMEOUT_EXCEPTION = "timeout.exception";
private String code;
public BussinessException() {
super();
}
public BussinessException(String message, Throwable cause) {
super(message, cause);
}
public BussinessException(String message) {
super(message);
}
public BussinessException(Throwable cause) {
super(cause);
}
public BussinessException(String code, String message, Throwable cause) {
super(message, cause);
this.code = code;
}
public BussinessException(String code, String message) {
super(message);
this.code = code;
}
}
业务异常构造类
public class BussinessExceptionMapper {
public static BussinessException build(String message) {
return build(BussinessException.SERVICE_FAIL, message);
}
public static BussinessException build(String code, String message) {
return new BussinessException(code, message);
}
public static BussinessException build(String message, Throwable cause) {
return build(BussinessException.SERVICE_FAIL, message, cause);
}
public static BussinessException build(String code, String message, Throwable cause) {
return new BussinessException(code, message, cause);
}
}
异常处理
@Controller 及 @RestController中的异常捕捉及处理
参数校检异常
使用hibernate validator校检参数，@Valid注解抛出的校检异常为MethodArgumentNotValidException，在@ExceptionHandler注释的方法中捕捉第一个错误信息
@ResponseBody
@ExceptionHandler(value = MethodArgumentNotValidException.class)
public Resp validHandler(MethodArgumentNotValidException ex) {
logger.error("ValidException:", ex);
List<ObjectError> list = ex
.getBindingResult().getAllErrors();
String errorMsg = StringUtils.defaultString(list.get(0).getDefaultMessage(), "参数错误");
return Resp.createError(RespCode.PARAM_ERR, "input.param.error", errorMsg);
}
业务异常
@ResponseBody
@ExceptionHandler(value = BussinessException.class)
public Resp bussinessHandler(BussinessException ex) {
logger.error("BussinessException:", ex);
return Resp.createError(RespCode.BUSINESS_INVALID, ex.getCode(), ex.getMessage());
}
Dubbo Rpc异常及运行时异常
@ControllerAdvice
public class GlobalControllerAdvice {
private Logger logger = LoggerFactory.getLogger(GlobalControllerAdvice.class);
@ResponseBody
@ExceptionHandler(value = MethodArgumentNotValidException.class)
public Resp validHandler(MethodArgumentNotValidException ex) {
logger.error("ValidException:", ex);
List<ObjectError> list = ex
.getBindingResult().getAllErrors();
String errorMsg = StringUtils.defaultString(list.get(0).getDefaultMessage(), "参数错误");
return Resp.createError(RespCode.PARAM_ERR, "input.param.error", errorMsg);
}
@ResponseBody
@ExceptionHandler(value = BussinessException.class)
public Resp bussinessHandler(BussinessException ex) {
logger.error("BussinessException:", ex);
return Resp.createError(RespCode.BUSINESS_INVALID, ex.getCode(), ex.getMessage());
}
@ResponseBody
@ExceptionHandler(value = Exception.class)
public Resp errorHandler(Exception e) {
logger.error("uncaught Exception:", e);
Resp resp;
if (e instanceof RpcException) {
resp = Resp.createError(RespCode.ERROR, "rpc.exception",
e.getMessage());
} else if (e instanceof RuntimeException) {
resp = Resp.createError(RespCode.ERROR, "runtime.exception",
"运行时异常,详见堆栈日志");
} else {
resp = Resp.createError(RespCode.BUSINESS_INVALID,
"service.fail", "服务失败");
}
return resp;
}
}
参考资料：
1.ControllerAdvice
2.RestControllerAdvice
