asm 实操 maven插件+asm字节码增强代码 maven自定义插件

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于 2025-04-17 16:20:07 发布

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分类专栏： java 文章标签： maven intellij-idea java

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1. 转转公众号发文有感：

加Log就卡？不加Log就瞎？”——这个插件治好了我的精神内耗

2.核心功能就是对某条存在的日志，进行控制是否打印日志

3. 使用到的工具： idea自定义插件 + maven自定义插件 + asm增强框架 + apollo 配置中心功能

4. 转转流程图：

5. 然后我就自己做了一个maven自定义插件 + asm 来复现下修改编译后的class功能：

使用到了maven3.9 + jdk17

6. 插件项目pom:

<?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>com.ddj</groupId>
    <artifactId>log-enhance</artifactId>
    <version>1.0.0</version>


    <packaging>maven-plugin</packaging>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>


    <dependencies>

        <dependency>
            <groupId>org.ow2.asm</groupId>
            <artifactId>asm</artifactId>
            <version>9.2</version>
        </dependency>


        <!-- ASM 字节码操作库 -->
        <dependency>
            <groupId>org.ow2.asm</groupId>
            <artifactId>asm-commons</artifactId>
            <version>9.2</version>
        </dependency>

        <!-- Maven Plugin 注解支持 -->
        <dependency>
            <groupId>org.apache.maven.plugin-tools</groupId>
            <artifactId>maven-plugin-annotations</artifactId>
            <version>3.9.0</version>
        </dependency>

        <!-- Maven Plugin API (包含 AbstractMojo) -->
        <dependency>
            <groupId>org.apache.maven</groupId>
            <artifactId>maven-plugin-api</artifactId>
            <version>3.9.9</version> <!-- 或使用与你的 Maven 版本兼容的版本 -->
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.34</version>
            <scope>provided</scope>
        </dependency>


<!--        &lt;!&ndash; SLF4J 门面 &ndash;&gt;-->
<!--        <dependency>-->
<!--            <groupId>org.slf4j</groupId>-->
<!--            <artifactId>slf4j-api</artifactId>-->
<!--            <version>1.7.36</version>-->
<!--        </dependency>-->
<!--        &lt;!&ndash; Logback 实现 &ndash;&gt;-->
<!--        <dependency>-->
<!--            <groupId>ch.qos.logback</groupId>-->
<!--            <artifactId>logback-classic</artifactId>-->
<!--            <version>1.2.12</version>-->
<!--        </dependency>-->



    </dependencies>


    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-plugin-plugin</artifactId>
                <version>3.13.1</version>
                <configuration>
                    <goalPrefix>enhance</goalPrefix> <!-- 自定义前缀 -->
                </configuration>
                <executions>
                    <execution>
                        <id>default-descriptor</id>
                        <phase>process-classes</phase>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

7. 核心类：

maven 插件需要继承的类：

package com.ddj.plugin;

import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugins.annotations.LifecyclePhase;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;

@Mojo(name = "enhance", defaultPhase = LifecyclePhase.PROCESS_CLASSES)
public class LogWrapperMojo extends AbstractMojo {
    
    @Parameter(defaultValue = "${project.build.outputDirectory}")
    private File outputDirectory;
    
    public void execute() throws MojoExecutionException {
        try {
            Files.walk(outputDirectory.toPath())
                .filter(p -> p.toString().endsWith(".class"))
                    .parallel()
                .forEach(p -> {
                    try {
                        byte[] original = Files.readAllBytes(p);
                        byte[] transformed = LogTransformer.transform(original);
                        Files.write(p, transformed);
                    } catch (IOException e) {
                        getLog().error("Failed to transform class: " + p, e);
                    }
                });
        } catch (IOException e) {
            throw new MojoExecutionException("Failed to process classes", e);
        }
    }
}

LogTransformer.class:

package com.ddj.plugin;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;

public class LogTransformer {
    public static byte[] transform(byte[] classData) {
        ClassReader cr = new ClassReader(classData);
        ClassWriter cw = new ClassWriter(cr, ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
        ClassVisitor cv = new LogClassVisitor(cw);
        cr.accept(cv, ClassReader.EXPAND_FRAMES);
        return cw.toByteArray();
    }
}

8. asm类：

package com.ddj.plugin;

import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

import static org.objectweb.asm.Opcodes.ACC_ABSTRACT;

/**
 *
 * @date 2025-04-17
 */
public class LogClassVisitor extends ClassVisitor {

    private  String className;

    public LogClassVisitor(ClassVisitor cv) {
        super(Opcodes.ASM9, cv);

    }

    @Override
    public void visit(int version, int access, String name, String signature,
                      String superName, String[] interfaces) {
        this.className = name;
        super.visit(version, access, name, signature, superName, interfaces);
    }
    
    @Override
    public MethodVisitor visitMethod(int access, String name, String desc,
                                     String signature, String[] exceptions) {
        MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
        // 跳过构造方法、静态块、抽象方法
        if (name.equals("<init>") || name.equals("<clinit>") || (access & ACC_ABSTRACT) != 0) {
            return mv;
        }

        return new LogMethodVisitor(api, mv, access, name, desc,className);
    }
}

方法修改：

package com.ddj.plugin;

import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.AdviceAdapter;

public class LogMethodVisitor extends AdviceAdapter {

    private final String methodName;
    private final String className;

    private int startTimeVarIndex; // 局部变量索引，用于存储开始时间
    private int durationVarIndex; // 局部变量索引，用于存储耗时

    protected LogMethodVisitor(int api, MethodVisitor mv, int access,
                               String name, String desc, String className) {
        super(api, mv, access, name, desc);
        this.methodName = name;
        this.className = className;
    }

    @Override
    protected void onMethodEnter() {
        // 记录方法开始时间
        // 获取当前时间并存储在局部变量中
        visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J", false);
        startTimeVarIndex = newLocal(Type.LONG_TYPE); // 分配一个局部变量来存储开始时间，并获取其索引
        storeLocal(startTimeVarIndex); // 使用正确的索引存储值
    }

    @Override
    protected void onMethodExit(int opcode) {
        if (opcode != ATHROW) { // 跳过异常退出的情况
            // 计算方法耗时
            // 获取当前时间
            visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J", false);
            // 加载开始时间
            loadLocal(startTimeVarIndex); // 使用正确的索引加载值
            // 计算时间差（当前时间 - 开始时间）
            visitInsn(LSUB); // 长整型减法

            // 将结果存储在局部变量中
            durationVarIndex = newLocal(Type.LONG_TYPE); // 分配一个局部变量来存储耗时，并获取其索引
            storeLocal(durationVarIndex); // 使用正确的索引存储值

            // 插入日志代码
            visitLdcInsn(className);
            visitMethodInsn(INVOKESTATIC, "org/slf4j/LoggerFactory", "getLogger",
                    "(Ljava/lang/String;)Lorg/slf4j/Logger;", false);

            // 加载耗时（从局部变量中）
            loadLocal(durationVarIndex); // 使用正确的索引加载值
            // 将长整型转换为字符串
            visitMethodInsn(INVOKESTATIC, "java/lang/Long", "toString", "(J)Ljava/lang/String;", false);

            // 构建日志消息
            visitTypeInsn(NEW, "java/lang/StringBuilder");
            visitInsn(DUP);
            visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "()V", false);
            visitLdcInsn("Method " + methodName + " took ");
            visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
            visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
            visitLdcInsn("ms");
            visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
            visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);

            // 调用日志方法
            visitMethodInsn(INVOKEINTERFACE, "org/slf4j/Logger", "info", "(Ljava/lang/String;)V", true);
        }
    }
}

9. 然后将该模块 maven install到本地库里面，在另外一个java 17 相同maven 中，引入插件，就可以了

另外一个项目中，我是多模块，所以在需要模块中，引入增强，不能在父模块配置，不然会报错

<!-- 子模块 依赖 -->
<build>
    <plugins>
        <plugin>
            <groupId>com.ddj</groupId>
            <artifactId>log-enhance</artifactId>
            <version>1.0.0</version>
            <executions>
                <execution>
                    <phase>process-classes</phase>
                    <goals>
                        <goal>enhance</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

10：然后在这个模块，点击idea的 maven插件，package

11. 原始文件：

11. 增强后的class文件：

 public void publish(UserRegisterEvent event) {
        long var2 = System.currentTimeMillis();
        log.info("------ {}", LocalDateTime.now());
        long var4 = System.currentTimeMillis() - var2;
        LoggerFactory.getLogger("net/csig/vs/infra/acl/publisher/UserRegisterEventPublisherImpl").info(Long.toString(var4).append((new StringBuilder()).append("Method publish took ")).append("ms").toString());
    }

12. 最主要的是继承了AdviceAdapter的类：LogMethodVisitor

方法：OnMethodEnter(), OnMethodExit(int opcode);

13. 核心逻辑验证完毕

未完成：

1. 从apollo 获取是否开启日志配置开关，根据是否开启进行修改两个asm方法

2. idea插件修改apollo 配置中心参数

3. onMethodEnter(), OnMethodExit()两个核心方法的asm编程，进行代码增删