问题描述

1、我们意图在实际操作之前加入一些字节码进行监控，例如对 慢sql, dubbo 并发 ,开发发布对时候对mybatis/ibatis对配置文件做检查

问题出现的环境背景及自己尝试过哪些方法

2、我们使用 Instrumentation 在启动的时候，将我们监控开发的 Agent jar 包导入即可，但是发现使用 javassist 的如下代码不起作用

        ClassPool pool = new ClassPool();//这一行之后就没有运行了，
        byte[] transformed = new byte[0];
        CtClass cl = null;
        try {
            cl = pool.get(className.replaceAll("/", "."));
            System.out.println("four");
            CtBehavior[] methods = cl.getDeclaredBehaviors();
            for (CtBehavior method : methods) {
                if (!method.isEmpty()) {
                    doMethod(method);
                }
            }
            transformed = cl.toBytecode();
        } catch (CannotCompileException | NotFoundException | IOException io) {
            io.printStackTrace();
        } finally {
            if (cl != null) {
                cl.detach();
            }
        }
        return transformed;

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>top.huzhurong.agent</groupId>
    <artifactId>test</artifactId>
    <version>1.0-SNAPSHOT</version>


    <dependencies>
        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.23.1-GA</version>
        </dependency>
    </dependencies>
    
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.1</version>
                <configuration>
                    <target>1.8</target>
                    <source>1.8</source>
                    <encoding>utf-8</encoding>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.3.1</version>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                        </manifest>
                        <manifestEntries>
                            <Premain-Class>test.Agent</Premain-Class>
                            <Boot-Class-Path>javassist-3.23.1-GA.jar</Boot-Class-Path>
                            <Can-Redefine-Classes>true</Can-Redefine-Classes>
                            <Can-Set-Native-Method-Prefix>true</Can-Set-Native-Method-Prefix>
                        </manifestEntries>
                    </archive>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

google，百度也没有找到什么，本身也不太好调试，以前使用 ASM 是可以的。提前感谢