前阵子朋友他老大叫他实现这么一个功能,就是低侵入的记录接口每次的请求响应日志,然后并统计每次请求调用的成功、失败次数以及响应耗时,当时朋友的实现思路是在每个业务的controller的方法上加一个自定义注解,然后写一个aop,以这个自定义注解为pointcut来记录日志。
这种AOP+注解来实现日志记录,应该是很常见的实现方式。然而朋友在落地的时候,发现项目要加自定义注解的地方太多。后面我就跟他说,那就不写注解,直接以形如下
execution(* com.github.lybgeek.logaop.service..*.*(..))
这样不行吗?他说他这个功能他老大是希望给各个项目组使用,像我上面的方法,估计行不通,我就问他说为啥行不通,他说各个项目的包名都不一样,如果我那种思路,他就说这样在代码里poincut不得要这么写
execution(* com.github.lybgeek.a.service..*.*(..)
|| * com.github.lybgeek.b.service..*.*(..) || * com.github.lybgeek.c.service..*.*(..) )
这样每次新加要日志记录,都得改切面代码,还不如用自定注解来的好。听完他的解释,我一脸黑人问号脸。于是就趁着5.1假期期间,写个demo实现上面的需求
低侵入的记录接口每次的请求响应日志,然后并统计每次请求调用的成功、失败次数以及响应耗时
这个业务需求应该算是很简单,实现的难点就在于低侵入,提到低侵入,我首先想到是使用者无需写代码,或者只需写少量代码或者仅需简单配置一下,最好能做到业务无感知。
我这边提供2种思路
1、什么是javaagent
javaagent是一个简单优雅的java agent,利用java自带的instrument特性+javassist/byte-buddy字节码可以实现对类的拦截或者增强。
javaAgent 是运行在 main方法之前的拦截器,它内定的方法名叫 premain ,也就是说先执行 premain 方法然后再执行 main 方法
2、如何实现一个javaagent
示例:
public class AgentDemo {
public static void premain(String agentArgs, Instrumentation inst) {
System.out.println("agentArgs : " + agentArgs);
inst.addTransformer(new DefineTransformer(),true);
}
static class DefineTransformer implements ClassFileTransformer {
@Override
public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
System.out.println("premain load Class:" + className);
return classfileBuffer;
}
}
}
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.2.0</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
</manifest>
<manifestEntries>
<Premain-Class>com.github.lybgeek.agent.ServiceLogAgent</Premain-Class>
<Agent-Class>com.github.lybgeek.agent.ServiceLogAgent</Agent-Class>
<Can-Redefine-Classes>true</Can-Redefine-Classes>
<Can-Retransform-Classes>true</Can-Retransform-Classes>
</manifestEntries>
</archive>
</configuration>
</plugin>
3、业务代码如何使用javagent
java -javaagent:agentjar文件的位置 [= 传入 premain的参数 ] -jar 要运行的jar文件
注:-javaagent一定要在-jar之前,不然不会生效
1、什么是byte-buddy
Byte Buddy是一个JVM的运行时代码生成器,你可以利用它创建任何类,且不像JDK动态代理那样强制实现一个接口。Byte Buddy还提供了简单的API,便于手工、通过Java Agent,或者在构建期间修改字节码
2、byte-buddy教程
注: 如果再介绍byte-buddy使用,则篇幅会比较长,因此提供以下2个byte-buddy学习链接,感兴趣的朋友可以点击查看
https://blog.gmem.cc/byte-buddy-study-note
https://notes.diguage.com/byte-buddy-tutorial/
1、编写agent入口类
public class ServiceLogAgent {
public static String base_package_key = "agent.basePackage";
public static void premain(String agentArgs, Instrumentation inst) {
System.out.println("loaded agentArgs :" + agentArgs);
Properties properties = PropertiesUtils.getProperties(agentArgs);
ServiceLogHelperFactory serviceLogHelperFactory = new ServiceLogHelperFactory(properties);
serviceLogHelperFactory.getServiceLogHelper().initTable();
AgentBuilder.Transformer transformer = (builder, typeDescription, classLoader, javaModule) -> {
return builder
.method(ElementMatchers.<MethodDescription>any()) // 拦截任意方法
.intercept(MethodDelegation.to(new ServiceLogInterceptor(serviceLogHelperFactory))); // 委托
};
AgentBuilder.Listener listener = new AgentBuilder.Listener() {
private Log log = LogFactory.getLog(AgentBuilder.Listener.class);
@Override
public void onDiscovery(String s, ClassLoader classLoader, JavaModule javaModule, boolean b) {
}
@Override
public void onTransformation(TypeDescription typeDescription, ClassLoader classLoader, JavaModule javaModule, boolean b, DynamicType dynamicType) {
}
@Override
public void onIgnored(TypeDescription typeDescription, ClassLoader classLoader, JavaModule javaModule, boolean b) {
}
@Override
public void onError(String s, ClassLoader classLoader, JavaModule javaModule, boolean b, Throwable throwable) {
log.error(throwable.getMessage(),throwable);
}
@Override
public void onComplete(String s, ClassLoader classLoader, JavaModule javaModule, boolean b) {
}
};
new AgentBuilder
.Default()
// 指定需要拦截的类
.type(ElementMatchers.nameStartsWith(properties.getProperty(base_package_key)))
.and(ElementMatchers.isAnnotatedWith(Service.class))
.transform(transformer)
.with(listener)
.installOn(inst);
}
}
2、编写拦截器
public class ServiceLogInterceptor {
private Log log = LogFactory.getLog(ServiceLogInterceptor.class);
private ServiceLogHelperFactory serviceLogHelperFactory;
public ServiceLogInterceptor(ServiceLogHelperFactory serviceLogHelperFactory) {
this.serviceLogHelperFactory = serviceLogHelperFactory;
}
@RuntimeType
public Object intercept(@AllArguments Object[] args, @Origin Method method, @SuperCall Callable<?> callable) {
long start = System.currentTimeMillis();
long costTime = 0L;
String status = ServiceLog.SUCEESS;
Object result = null;
String respResult = null;
try {
// 原有函数执行
result = callable.call();
respResult = JsonUtils.object2json(result);
} catch (Exception e){
log.error(e.getMessage(),e);
status = ServiceLog.FAIL;
respResult = e.getMessage();
} finally{
costTime = System.currentTimeMillis() - start;
saveLog(args, method, costTime, status, respResult);
}
return result;
}
private void saveLog(Object[] args, Method method, long costTime, String status, String respResult) {
if(!isSkipLog(method)){
ServiceLog serviceLog = serviceLogHelperFactory.createServiceLog(args,method);
serviceLog.setCostTime(costTime);
serviceLog.setRespResult(respResult);
serviceLog.setStatus(status);
ServiceLogHelper serviceLogHelper = serviceLogHelperFactory.getServiceLogHelper();
serviceLogHelper.saveLog(serviceLog);
}
}
private boolean isSkipLog(Method method){
ServiceLogProperties serviceLogProperties = serviceLogHelperFactory.getServiceLogProperties();
List<String> skipLogServiceNameList = serviceLogProperties.getSkipLogServiceNameList();
if(!CollectionUtils.isEmpty(skipLogServiceNameList)){
String currentServiceName = method.getDeclaringClass().getName() + ServiceLogProperties.CLASS_METHOD_SPITE + method.getName();
return skipLogServiceNameList.contains(currentServiceName);
}
return false;
}
}
3、通过maven将agent打包成jar
4、效果演示
首先idea在启动类的vm参数,加入形如下内容
-javaagent:F:\springboot-learning\springboot-agent\springboot-javaagent-log\target\agent-log.jar=F:\springboot-learning\springboot-agent\springboot-javaagent-log\target\classes\agent.properties
效果图
注: 其实朋友那种方式也差不多可以了,只需把poincut的外移到配置文件文件即可
1、编写切面
@Slf4j
public class ServiceLogAdvice implements MethodInterceptor {
private LogService logService;
public ServiceLogAdvice(LogService logService) {
this.logService = logService;
}
@Override
public Object invoke(MethodInvocation invocation) {
long start = System.currentTimeMillis();
long costTime = 0L;
String status = ServiceLog.SUCEESS;
Object result = null;
String respResult = null;
try {
// 原有函数执行
result = invocation.proceed();
respResult = JSON.toJSONString(result);
} catch (Throwable e){
log.error(e.getMessage(),e);
status = ServiceLog.FAIL;
respResult = e.getMessage();
} finally{
costTime = System.currentTimeMillis() - start;
saveLog(invocation.getArguments(), invocation.getMethod(), costTime, status, respResult);
}
return result;
}
private void saveLog(Object[] args, Method method, long costTime, String status, String respResult) {
ServiceLog serviceLog = ServiceLog.builder()
.serviceName(method.getDeclaringClass().getName())
.costTime(costTime)
.methodName(method.getName())
.status(status)
.reqArgs(JSON.toJSONString(args))
.respResult(respResult).build();
logService.saveLog(serviceLog);
}
}
2、注入切面bean
@Bean
@ConditionalOnMissingBean
public AspectJExpressionPointcutAdvisor serviceLogAspectJExpressionPointcutAdvisor(AopLogProperties aopLogProperties) {
AspectJExpressionPointcutAdvisor advisor = new AspectJExpressionPointcutAdvisor();
advisor.setExpression(aopLogProperties.getPointcut());
advisor.setAdvice(serviceLogAdvice());
return advisor;
}
3、编写自动装配类
@Configuration
@EnableConfigurationProperties(AopLogProperties.class)
@ConditionalOnProperty(prefix = "servicelog",name = "enabled",havingValue = "true",matchIfMissing = true)
public class AopLogAutoConfiguration {
@Autowired
private JdbcTemplate jdbcTemplate;
@Bean
@ConditionalOnMissingBean
public LogService logService(){
return new LogServiceImpl(jdbcTemplate);
}
@Bean
@ConditionalOnMissingBean
public ServiceLogAdvice serviceLogAdvice(){
return new ServiceLogAdvice(logService());
}
@Bean
@ConditionalOnMissingBean
public AspectJExpressionPointcutAdvisor serviceLogAspectJExpressionPointcutAdvisor(AopLogProperties aopLogProperties) {
AspectJExpressionPointcutAdvisor advisor = new AspectJExpressionPointcutAdvisor();
advisor.setExpression(aopLogProperties.getPointcut());
advisor.setAdvice(serviceLogAdvice());
return advisor;
}
}
4、编写spring.factories
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.github.lybgeek.logaop.config.AopLogAutoConfiguration
5、效果演示
在业务代码做如下配置
<dependency>
<groupId>com.github.lybgeek</groupId>
<artifactId>aoplog-springboot-starter</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
servicelog:
pointcut: execution(* com.github.lybgeek.mock.service.client..*.*(..))
enabled: true
以上主要列举了通过javaagent和aop加自动装配2两种方式来实现低侵入记录日志。其实这两种实现在一些开源的方案用得挺多的,比如byte-buddy在skywalking和arthas就有使用到,比如MethodInterceptor 在spring事务中就有用到。所以多看些源码,在设计方案时,有时候会产生意想不到的火花
https://github.com/lyb-geek/springboot-learning/tree/master/springboot-agent
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。