Byte buddy print execution time and method link tracking

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Preface

Many small partners may encounter the problem of printing execution time in the development process . The normal operation is to write a few lines of code in the method to be monitored to print the execution time , Hard working friends will write aop To print the execution time , But most of the time , We don't need to bring this code into the production environment , So you should find the relevant code to delete when you go online . This article provides a set of Java Probe program , It can be developed or tested （ Pressure measurement ） Phase assists in debugging code . Also provide generation traceId, Easy to track method links .
First provide the source code address ：

https://github.com/Jamsw/bytebuddy-agent.git

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Tips ： The following is the main body of this article , The following cases can be used for reference

One 、byte-buddy What is it? ？

Byte Buddy It's a JVM Runtime code generator for , Simple is provided API, It's easy to do by hand 、 adopt Java Agent, Or modify bytecode during build .

Two 、 Use steps

1. Translate it into jar package

The order is as follows ：

mvn clean package

After execution , Will be in target Generate... In directory jar Packages and config Catalog .jar Bao He config It needs to be in the same directory . As shown in the figure below ：

config The directory contains agent.config The configuration file , There are two parameters ：

agent.packname = com.smart.tcp.gateway
agent.ignore = com.smart.tcp.gateway.client.test.UserModel,com.smart.tcp.gateway.client.test.UserModel

agent.packname： The package path where the log needs to be printed .
agent.ignore： Classes to ignore .

2. To configure Java probe

take idea Examples of development tools , Need to be in VM options Configure the following parameters ：

-javaagent:path（ Fill in the directory address of the local computer or server ）/log-agent-1.0-SNAPSHOT.jar

3. Effect demonstration

tid:71b8195c-eadc-4385-8db1-a8fb414743e8:INFO> The method level 【 Class name :com.smart.tcp.gateway.client.test.UserMapper   Method name ：<init>  The execution time is :0ms】
tid:71b8195c-eadc-4385-8db1-a8fb414743e8:INFO> The method level 【 Class name :com.smart.tcp.gateway.client.test.UserMapper   Method name ：selectUserInfo  The execution time is :0ms】
tid:71b8195c-eadc-4385-8db1-a8fb414743e8:INFO> The method level 【 Class name :com.smart.tcp.gateway.client.test.UserServiceImpl   Method name ：getUserInfo  The execution time is :10ms】
tid:71b8195c-eadc-4385-8db1-a8fb414743e8:INFO> Interface level 【url path:/user/getInfo  Enter the reference :key=userId value=123456, The ginseng :{
    "userName":"smart","userId":null}  Overall time-consuming interface :109ms】

3、 ... and 、 Encounter problems

1. Pile driving

Because you want to print the interface return value , So we need to HttpServletResponse Secondary packaging ,agent The program needs to encapsulate the secondary reponse To the method of interception , Therefore, piling is required .
Rewrite first superCall Method , as follows ：

public interface OverrideCallable {
    
    Object call(Object[] args);
}

And then in ProcessRequestInterceptor Method input parameter input OverrideCallable, as follows ：

public static Object intercept(@AllArguments Object[] allArguments, @Morph OverrideCallable zuper)

stay premain Add piling configuration .withDefaultConfiguration().withBinders(Morph.Binder.install(OverrideCallable.class)), As shown below ：

agentBuilder.ignore(ElementMatchers.named("javax.servlet.http"))
                .type(ElementMatchers.named("org.springframework.web.servlet.FrameworkServlet"))
                .transform((builder, type, classLoader, module) ->
                        builder.method(ElementMatchers.named("processRequest"))
                                .intercept(MethodDelegation.withDefaultConfiguration().withBinders(Morph.Binder.install(OverrideCallable.class)).to(ProcessRequestInterceptor.class)))
                .installOn(inst);

2.mybatis Report errors

because byte-buddy The original class name will be modified when injecting code , therefore mybatis When you query a method by class name, you will report java.lang.NoSuchMethodError Report errors , The solution is to configure not to modify the class name .disableClassFormatChanges(), The specific code is as follows ：

agentBuilder.disableClassFormatChanges().ignore(e)
                .type(ElementMatchers.nameStartsWith(Config.Agent.packname))
                .transform(transformer).installOn(inst);