有的时候,为了保全代码的简洁,我们不希望在程序中看到一些跟程序逻辑的代码,譬如异常日志打印,这个时候就需要我们对程序中的异常日志进行统一的管理。spring aop 可以在不破坏程序逻辑的情况下很好的完成我们上面的需求。本文对对日志的处理使用到了ThrowsAdvice接口和spring aop
ThrowsAdvice接口
1 /* 2 * Copyright 2002-2008 the original author or authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.springframework.aop; 18 19 /** 20 * Tag interface for throws advice. 21 * 22 * <p>There are not any methods on this interface, as methods are invoked by 23 * reflection. Implementing classes must implement methods of the form: 24 * 25 * <pre class="code">void afterThrowing([Method, args, target], ThrowableSubclass);</pre> 26 * 27 * <p>Some examples of valid methods would be: 28 * 29 * <pre class="code">public void afterThrowing(Exception ex)</pre> 30 * <pre class="code">public void afterThrowing(RemoteException)</pre> 31 * <pre class="code">public void afterThrowing(Method method, Object[] args, Object target, Exception ex)</pre> 32 * <pre class="code">public void afterThrowing(Method method, Object[] args, Object target, ServletException ex)</pre> 33 * 34 * The first three arguments are optional, and only useful if we want further 35 * information about the joinpoint, as in AspectJ <b>after-throwing</b> advice. 36 * 37 * <p><b>Note:</b> If a throws-advice method throws an exception itself, it will 38 * override the original exception (i.e. change the exception thrown to the user). 39 * The overriding exception will typically be a RuntimeException; this is compatible 40 * with any method signature. However, if a throws-advice method throws a checked 41 * exception, it will have to match the declared exceptions of the target method 42 * and is hence to some degree coupled to specific target method signatures. 43 * <b>Do not throw an undeclared checked exception that is incompatible with 44 * the target method‘s signature!</b> 45 * 46 * @author Rod Johnson 47 * @author Juergen Hoeller 48 * @see AfterReturningAdvice 49 * @see MethodBeforeAdvice 50 */ 51 public interface ThrowsAdvice extends AfterAdvice { 52 53 }
看接口说明可知,该接口上没有任何方法,但是实现了这个接口的类必须至少实现以下4个方法中的一个,否则程序报:
Caused by: java.lang.IllegalArgumentException: At least one handler method must be found in class
接口中的异常类可以为自己自定义的异常类,方法是通过反射调用。
1 public void afterThrowing(Exception ex) 2 public void afterThrowing(RemoteException) 3 public void afterThrowing(Method method, Object[] args, Object target, Exception ex) 4 public void afterThrowing(Method method, Object[] args, Object target, ServletException ex)
自定义异常类
1 package com.apt.study.exception; 2 3 public class StudyException extends RuntimeException { 4 5 /** 6 * 7 */ 8 private static final long serialVersionUID = -6183216129830888521L; 9 10 /** 11 * 异常信息 12 */ 13 protected String message; 14 15 /** 16 * 异常编码 17 */ 18 protected int code; 19 20 public static final StudyException PARAM_VALIDATE_EXCEPTION = new StudyException(1234,"参数校验出错"); 21 22 public StudyException(int code, String msgFormat, Object... args) { 23 super(String.format(msgFormat, args)); 24 this.code = code; 25 this.message = String.format(msgFormat, args); 26 } 27 28 public StudyException(String message, Throwable cause) { 29 super(message, cause); 30 } 31 32 public StudyException(Throwable cause) { 33 super(cause); 34 } 35 36 public StudyException(String message) { 37 super(message); 38 } 39 40 public String getMessage() { 41 return message; 42 } 43 44 public void setMessage(String message) { 45 this.message = message; 46 } 47 48 public int getCode() { 49 return code; 50 } 51 52 public void setCode(int code) { 53 this.code = code; 54 } 55 56 57 }
异常日志处理类
1 package com.apt.study.exception; 2 3 import java.lang.reflect.Method; 4 5 import org.slf4j.Logger; 6 import org.slf4j.LoggerFactory; 7 import org.springframework.aop.ThrowsAdvice; 8 9 public class ExceptionLogHandler implements ThrowsAdvice{ 10 11 public Logger logger = LoggerFactory.getLogger(ExceptionLogHandler.class); 12 13 public void afterThrowing(Method method, Object[] args, Object target, StudyException ex) { 14 logger.error("ExceptionLogHandler--StudyExcception"); 15 logger.info("-------errCode:" + ex.getCode() + "; errMessage:" + ex.getMessage()); 16 errorClassInfo(ex); 17 logger.info("-------" + ex.fillInStackTrace()); 18 } 19 20 public void afterThrowing(Method method, Object[] args, Object target, Exception ex) { 21 22 logger.error("ExceptionLogHandler--Exception"); 23 logger.error("------->Erro Class: "+ target.getClass().getName()); 24 logger.error("------->Error method:"+ method.getName()); 25 26 if(args != null) { 27 for(int i=0; i<args.length; i++) { 28 logger.error("------->args[" + i + "]: " + args[i]); 29 } 30 } 31 32 logger.error("------->Exception class: " + ex.getClass().getName()); 33 errorClassInfo(ex); 34 logger.error("------->" + ex.fillInStackTrace()); 35 } 36 37 //打印抛出异常地方的信息 38 private void errorClassInfo(Exception ex) { 39 /* 40 * ex.getStackTrace()返回堆栈跟踪元素的数组,每个元素表示一个堆栈帧。数组的第零个元素(假定数据的长度为非零)表示堆栈顶部, 41 * 它是序列中最后的方法调用。 42 * 通常,这是创建和抛出该 throwable 的地方。数组的最后元素(假定数据的长度为非零)表示堆栈底部,它是序列中第一个方法调用 43 */ 44 StackTraceElement[] stackTraceElementArr= ex.getStackTrace(); 45 StackTraceElement stackTraceElement = stackTraceElementArr[0]; 46 logger.error("------->Erro File:" + stackTraceElement.getFileName()); 47 logger.error("------->Erro Method:" + stackTraceElement.getMethodName()); 48 logger.error("------->Erro Line:" + stackTraceElement.getLineNumber()); 49 } 50 51 }
spring-context.xml 配置
<!-- 异常信息 拦截 --> <bean id="exceptionLog" class="com.apt.study.exception.ExceptionLogHandler"></bean> <aop:config> <aop:pointcut id="exceptionTrade" expression="execution(* com.apt.study.service.*.*(..))" /> <aop:advisor pointcut-ref="exceptionTrade" advice-ref="exceptionLog"/> </aop:config>
时间: 2024-12-17 06:41:33