Spring-AOP之异常转换

引子

最近项目遇到了一个问题，就是说业务层向展现层需要转换成统一个异常类，并抛出异常，但是由于业务层的异常类过多，所以导致业务异常转换代码充斥着异常转换的代码，本着程序猿能省写代码就省写代码的原则，决定用Spring AOP来做一个切片，业务异常类转换.

最原始代码

最原始的代码，咱简称V1.0

 @Overridepublic GnAreaVo selectByID(GnAreaCondition condition) throws CallerException {try {//业务处理if (StringUtils.isEmpty(condition.getAreaCode()))throw new BusinessException("10001", "区域编码不能为空");Gson gson = new Gson();//处理结果return gson.fromJson(gson.toJson(iGnAreaBusinessService.selectByID(condition.getAreaCode())), GnAreaVo.class);} catch (BusinessException ex) {//throw new CallerException("100001", ex.getErrorMessage());} catch (SystemException ex) {//throw new CallerException("100001", ex.getMessage());} catch (Exception ex) {//throw new CallerException("10001", "系统异常");}}

升级版本

升级版本，简称V1.1，提取出一个公共类来处理

@Overridepublic GnAreaVo selectByID(GnAreaCondition condition) throws CallerException {try {//业务处理if (StringUtils.isEmpty(condition.getAreaCode()))throw new BusinessException("10001", "区域编码不能为空");Gson gson = new Gson();//处理结果return gson.fromJson(gson.toJson(iGnAreaBusinessService.selectByID(condition.getAreaCode())), GnAreaVo.class);} catch (BusinessException ex) {//throw DubboExceptAssembler.assemble(ex);} catch (SystemException ex) {//throw DubboExceptAssembler.assemble(ex);} catch (Exception ex) {//throw DubboExceptAssembler.assemble(ex);}}

最终版

代码更加简单了，并且能支持更加多异常类的转换，减少业务程序的无用代码，下面来看看怎么实现的。
首先写一个AOP

import com.ai.runner.base.exception.BusinessException;
import com.ai.runner.base.exception.SystemException;
import com.ai.runner.utils.util.DubboExceptAssembler;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.aspectj.lang.JoinPoint;public class DubboExceptionConvertInterceptor {private static final Logger logger = LogManager.getLogger(DubboExceptionConvertInterceptor.class);public void convertException(JoinPoint joinPoint, Exception error) {logger.error("执行{}类中的{}方法出错，出错原因:{}", joinPoint.getTarget().getClass().getName(),joinPoint.getSignature().getName());if (error instanceof SystemException) {throw DubboExceptAssembler.assemble((SystemException) error);}if (error instanceof BusinessException) {throw DubboExceptAssembler.assemble((BusinessException) error);}throw DubboExceptAssembler.assemble(error);}
}

Spring的配置：

<bean id="dubboExceptionConvertor" class="DubboExceptionConvertInterceptor"/><aop:config><aop:aspect id="aspectLoggging" ref="dubboExceptionConvertor"><aop:pointcut id="dubboExceptionThrowing"expression="execution (* com.ai.runner.center.common.api.*.impl.*.*(..))"/><aop:after-throwing method="convertException" throwing="error"pointcut-ref="dubboExceptionThrowing"/></aop:aspect></aop:config>

业务代码：

  @Overridepublic GnAreaVo selectByID(GnAreaCondition condition) throws CallerException {if (StringUtils.isEmpty(condition.getAreaCode()))throw new BusinessException("10001", "区域编码不能为空");Gson gson = new Gson();return gson.fromJson(gson.toJson(iGnAreaBusinessService.selectByID(condition.getAreaCode())), GnAreaVo.class);}

Done!