dubbo下的异常统一处理

dubbo下的异常统一处理

ps:lz最近写了一个统一异常处理模块,按等级高低发送给对应的负责人(该异常发生的类对应的包对应的模块),跟大家分享一下.异常统一处理需要类去实现javax.ws.rs的ExceptionMapper接口

public interface ExceptionMapper<E extends Throwable> {    /**     * Map an exception to a {@link javax.ws.rs.core.Response}. Returning     * {@code null} results in a {@link javax.ws.rs.core.Response.Status#NO_CONTENT}     * response. Throwing a runtime exception results in a     * {@link javax.ws.rs.core.Response.Status#INTERNAL_SERVER_ERROR} response.     *     * @param exception the exception to map to a response.     * @return a response mapped from the supplied exception.     */    Response toResponse(E exception);}

需要了解dubbo的ExceptionFilter的实现:

/*  * Copyright 1999-2011 Alibaba Group.  *    * Licensed under the Apache License, Version 2.0 (the "License");  * you may not use this file except in compliance with the License.  * You may obtain a copy of the License at  *    *      http://www.apache.org/licenses/LICENSE-2.0  *    * Unless required by applicable law or agreed to in writing, software  * distributed under the License is distributed on an "AS IS" BASIS,  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  * See the License for the specific language governing permissions and  * limitations under the License.  */  package com.alibaba.dubbo.rpc.filter;  import java.lang.reflect.Method;  import com.alibaba.dubbo.common.Constants;  import com.alibaba.dubbo.common.extension.Activate;  import com.alibaba.dubbo.common.logger.Logger;  import com.alibaba.dubbo.common.logger.LoggerFactory;  import com.alibaba.dubbo.common.utils.ReflectUtils;  import com.alibaba.dubbo.common.utils.StringUtils;  import com.alibaba.dubbo.rpc.Filter;  import com.alibaba.dubbo.rpc.Invocation;  import com.alibaba.dubbo.rpc.Invoker;  import com.alibaba.dubbo.rpc.Result;  import com.alibaba.dubbo.rpc.RpcContext;  import com.alibaba.dubbo.rpc.RpcException;  import com.alibaba.dubbo.rpc.RpcResult;  import com.alibaba.dubbo.rpc.service.GenericService;  /**  * ExceptionInvokerFilter  * <p>  * 功能：  * <ol>  * <li>不期望的异常打ERROR日志（Provider端）<br>  *     不期望的日志即是，没有的接口上声明的Unchecked异常。  * <li>异常不在API包中，则Wrap一层RuntimeException。<br>  *     RPC对于第一层异常会直接序列化传输(Cause异常会String化)，避免异常在Client出不能反序列化问题。  * </ol>  *   * @author william.liangf  * @author ding.lid  */  @Activate(group = Constants.PROVIDER)  public class ExceptionFilter implements Filter {      private final Logger logger;      public ExceptionFilter() {          this(LoggerFactory.getLogger(ExceptionFilter.class));      }      public ExceptionFilter(Logger logger) {          this.logger = logger;      }      public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {          try {              Result result = invoker.invoke(invocation);              if (result.hasException() && GenericService.class != invoker.getInterface()) {                  try {                      Throwable exception = result.getException();                      // 如果是checked异常，直接抛出                      if (! (exception instanceof RuntimeException) && (exception instanceof Exception)) {                          return result;                      }                      // 在方法签名上有声明，直接抛出                      try {                          Method method = invoker.getInterface().getMethod(invocation.getMethodName(), invocation.getParameterTypes());                          Class<?>[] exceptionClassses = method.getExceptionTypes();                          for (Class<?> exceptionClass : exceptionClassses) {                              if (exception.getClass().equals(exceptionClass)) {                                  return result;                              }                          }                      } catch (NoSuchMethodException e) {                          return result;                      }                      // 未在方法签名上定义的异常，在服务器端打印ERROR日志                      logger.error("Got unchecked and undeclared exception which called by " + RpcContext.getContext().getRemoteHost()                              + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName()                              + ", exception: " + exception.getClass().getName() + ": " + exception.getMessage(), exception);                      // 异常类和接口类在同一jar包里，直接抛出                      String serviceFile = ReflectUtils.getCodeBase(invoker.getInterface());                      String exceptionFile = ReflectUtils.getCodeBase(exception.getClass());                      if (serviceFile == null || exceptionFile == null || serviceFile.equals(exceptionFile)){                          return result;                      }                      // 是JDK自带的异常，直接抛出                      String className = exception.getClass().getName();                      if (className.startsWith("java.") || className.startsWith("javax.")) {                          return result;                      }                      // 是Dubbo本身的异常，直接抛出                      if (exception instanceof RpcException) {                          return result;                      }                      // 否则，包装成RuntimeException抛给客户端                      return new RpcResult(new RuntimeException(StringUtils.toString(exception)));                  } catch (Throwable e) {                      logger.warn("Fail to ExceptionFilter when called by " + RpcContext.getContext().getRemoteHost()                              + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName()                              + ", exception: " + e.getClass().getName() + ": " + e.getMessage(), e);                      return result;                  }              }              return result;          } catch (RuntimeException e) {              logger.error("Got unchecked and undeclared exception which called by " + RpcContext.getContext().getRemoteHost()                      + ". service: " + invoker.getInterface().getName() + ", method: " + invocation.getMethodName()                      + ", exception: " + e.getClass().getName() + ": " + e.getMessage(), e);              throw e;          }      }  }  

在此基础上,去实现ExceptionMapper<E extend throwable>抓取特定的异常,比如:

public class RpcExceptionMapperSupportWarning implements ExceptionMapper<RpcException>{@Override    public Response toResponse(RpcException e) {    FailedResponse faild = null;        if (e.getCause() instanceof ConstraintViolationException) {            EExceptionLevel level = EExceptionLevel.LEVEL_LOW;            ExceptionWarningFilter.FILTER.warning(e, level);            return this.rpcMapperSupper.toResponse(e);        }//else if(){}...        else {//RPC Call Failure!!!            EExceptionLevel level = EExceptionLevel.LEVEL_HIGH;            ExceptionWarningFilter.FILTER.warning(e, level);            faild = FailedResponse.ILLEGAL_RPC_CALL;        }        return Response.status(Response.Status.OK).entity(faild).type("application/json; charset=UTF-8").build();    }}

上述代码中的ExceptionWarningFilter类,便是处理异常的类:

public enum ExceptionWarningFilter {    FILTER;    private static Logger logger = LoggerFactory.getLogger(ExceptionWarningFilter.class);    private DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    public void warning(Throwable throwable,EExceptionLevel level){        Throwable exception = throwable.getCause();        if (exception == null) {            exception = throwable;        }        WarningMessage warningMessage = null;        Timestamp happenTimestamp =new Timestamp(new Date().getTime());        String exceptionStack = getExceptionStack(exception);//异常栈        String ip = RpcContext.getContext().getLocalHost();        if (exception instanceof RuntimeException) {            String message = exception.getLocalizedMessage();            if (message!=null) {                warningMessage = getWarningInfo(message,warningMessage);            }else{                for(StackTraceElement el : exception.getStackTrace()){                    warningMessage = getWarningInfo(el,exception,warningMessage);                    break;                }            }        }else {            for (StackTraceElement el : exception.getStackTrace()) {                if (el.getClassName().startsWith("com.java")) {                    warningMessage = getWarningInfo(el,exception,warningMessage);                    break;                }                   }            if (warningMessage==null) {                for(StackTraceElement el : exception.getStackTrace()){                    warningMessage = getWarningInfo(el,exception,warningMessage);                    break;                }            }        }        callingTheExceptionNotificationService(level,happenTimestamp,warningMessage,exceptionStack,ip);    }

    private String getExceptionStack(Throwable exception) {        String exceptionStack = null;        ByteArrayOutputStream baos = new ByteArrayOutputStream();        exception.printStackTrace(new PrintStream(baos));        if (baos!=null) {            exceptionStack =  baos.toString();        }        return exceptionStack;    }

    private void callingTheExceptionNotificationService(EExceptionLevel level, Timestamp happenTimestamp,            WarningMessage warningMessage, String exceptionStack, String ip) {        String happenTime = df.format(happenTimestamp==null?new Date().getTime():happenTimestamp);        FileSystemXmlApplicationContext fsxac = null;        try {            fsxac = new FileSystemXmlApplicationContext("/server-spring.xml");            IExceptionNotifyService exceptionNotifyService = (IExceptionNotifyService) fsxac.getBean("exceptionNotifyService");            exceptionNotifyService.exceptionNotify(level,                    getWarningInfo(happenTimestamp,warningMessage,exceptionStack,ip));            logger.debug("发送异常报警信息(时间:{},info:{}",happenTime,warningMessage.toString());        } catch (Exception e) {            e.printStackTrace();            logger.debug(e.toString());        }finally {            if (fsxac!=null) {                fsxac.close();                                      }        }    }

    lz只贴了主要的方法,其他的就是对bean的数据的封装,就不贴了    这里lz使用了一个枚举类来作为这个异常处理类,主要是想运用一个单例模式,这个用法可在efftive java中找到,这种写法在功能上与共有域方法相近，但是它更简洁，无偿地提供了序列化机制，绝对防止对此实例化，即使是在面对复杂的序列化或者反射攻击的时候。虽然这中方法还没有广泛采用，但是单元素的枚举类型已经成为实现Singleton的最佳方法。    lz主要碰到的问题是,这个实现了的异常mapper并不支持spring的antowired注释,大概的解释应该是他并不会被声明为一个bean?lz的解决方法是自己去配置文件里get一个,如果有更好的解决方法欢迎评论@,这里还有一个要注意的是,dubbo的异常处理中,不符合条件的,会包装成一个runtimeException再抛出,所以lz在处理类中对 instanceof runtimeException的异常做了处理,lz的处理其实说起来很白痴,就是获取他携带的LocalizedMessage然后对其做处理,获取异常发生的类,方法,行以及对应的包名.    之后就是根据业务需求将异常信息发送给对应负责人了,出去性能的考虑,lz和同事的方案为将该信息发送到消息队列上去,并设置该异常类型的redis缓存,用于判断相隔多少时间发送,而消费方则去收取消息队列上对应的topic数据去做处理.