├── .gitignore
├── bytebuddy
    ├── dependency-reduced-pom.xml
    ├── pom.xml
    └── src
    │   └── main
    │       ├── java
    │           └── cn
    │           │   └── iocoder
    │           │       └── learning
    │           │           └── bytebuddy
    │           │               ├── Agent.java
    │           │               ├── Dog.java
    │           │               ├── Example001.java
    │           │               ├── Example002.java
    │           │               ├── IAnimal.java
    │           │               └── MyServiceInterceptor.java
    │       └── resources
    │           └── META-INF
    │               └── MANIFEST.MF
├── example01
    ├── pom.xml
    ├── readme.md
    └── src
    │   └── main
    │       └── java
    │           └── cn
    │               └── iocoder
    │                   └── learning
    │                       ├── Cat.java
    │                       ├── Dog.java
    │                       └── Main.java
├── javaagent01
    ├── pom.xml
    └── src
    │   └── main
    │       ├── java
    │           └── cn
    │           │   └── iocoder
    │           │       └── learning
    │           │           └── javaagent01
    │           │               ├── Agent.java
    │           │               └── ClassFileTransformerDemo.java
    │       └── resources
    │           └── META-INF
    │               └── MANIFEST.MF
└── pom.xml


/.gitignore:
--------------------------------------------------------------------------------
 1 | # Compiled class file
 2 | *.class
 3 | 
 4 | # Log file
 5 | *.log
 6 | 
 7 | # BlueJ files
 8 | *.ctxt
 9 | 
10 | # Mobile Tools for Java (J2ME)
11 | .mtj.tmp/
12 | 
13 | # Package Files #
14 | *.jar
15 | *.war
16 | *.ear
17 | *.zip
18 | *.tar.gz
19 | *.rar
20 | 
21 | # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
22 | hs_err_pid*
23 | 


--------------------------------------------------------------------------------
/bytebuddy/dependency-reduced-pom.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <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/maven-v4_0_0.xsd">
 3 |   <parent>
 4 |     <artifactId>parent</artifactId>
 5 |     <groupId>cn.iocoder.learning</groupId>
 6 |     <version>1.0-SNAPSHOT</version>
 7 |   </parent>
 8 |   <modelVersion>4.0.0</modelVersion>
 9 |   <artifactId>bytebuddy</artifactId>
10 |   <build>
11 |     <finalName>agent</finalName>
12 |     <plugins>
13 |       <plugin>
14 |         <artifactId>maven-shade-plugin</artifactId>
15 |         <version>2.4.1</version>
16 |         <executions>
17 |           <execution>
18 |             <phase>package</phase>
19 |             <goals>
20 |               <goal>shade</goal>
21 |             </goals>
22 |             <configuration>
23 |               <shadedArtifactAttached>false</shadedArtifactAttached>
24 |               <createDependencyReducedPom>true</createDependencyReducedPom>
25 |               <createSourcesJar>true</createSourcesJar>
26 |               <shadeSourcesContent>true</shadeSourcesContent>
27 |               <transformers>
28 |                 <transformer>
29 |                   <manifestEntries>
30 |                     <Premain-Class>cn.iocoder.learning.bytebuddy.Agent</Premain-Class>
31 |                   </manifestEntries>
32 |                 </transformer>
33 |               </transformers>
34 |               <artifactSet>
35 |                 <excludes>
36 |                   <exclude>com.lmax:*</exclude>
37 |                   <exclude>org.apache.httpcomponents:*</exclude>
38 |                   <exclude>commons-logging:*</exclude>
39 |                   <exclude>commons-codec:*</exclude>
40 |                   <exclude>*:gson</exclude>
41 |                   <exclude>io.grpc:*</exclude>
42 |                   <exclude>io.netty:*</exclude>
43 |                   <exclude>com.google.*:*</exclude>
44 |                   <exclude>com.google.guava:guava</exclude>
45 |                 </excludes>
46 |               </artifactSet>
47 |             </configuration>
48 |           </execution>
49 |         </executions>
50 |       </plugin>
51 |     </plugins>
52 |   </build>
53 |   <properties>
54 |     <shade.net.bytebuddy.target>${shade.package}.${shade.net.bytebuddy.source}</shade.net.bytebuddy.target>
55 |     <shade.package>org.skywalking.apm.dependencies</shade.package>
56 |     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
57 |     <shade.net.bytebuddy.source>net.bytebuddy</shade.net.bytebuddy.source>
58 |   </properties>
59 | </project>
60 | 
61 | 


--------------------------------------------------------------------------------
/bytebuddy/pom.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <project xmlns="http://maven.apache.org/POM/4.0.0"
 3 |          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4 |          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5 |     <parent>
 6 |         <artifactId>parent</artifactId>
 7 |         <groupId>cn.iocoder.learning</groupId>
 8 |         <version>1.0-SNAPSHOT</version>
 9 |     </parent>
10 |     <modelVersion>4.0.0</modelVersion>
11 | 
12 |     <artifactId>bytebuddy</artifactId>
13 | 
14 |     <properties>
15 |         <shade.package>org.skywalking.apm.dependencies</shade.package>
16 |         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
17 |         <shade.net.bytebuddy.source>net.bytebuddy</shade.net.bytebuddy.source>
18 |         <shade.net.bytebuddy.target>${shade.package}.${shade.net.bytebuddy.source}</shade.net.bytebuddy.target>
19 |     </properties>
20 | 
21 |     <dependencies>
22 |         <dependency>
23 |             <groupId>net.bytebuddy</groupId>
24 |             <artifactId>byte-buddy</artifactId>
25 |             <version>1.7.9</version>
26 |         </dependency>
27 |     </dependencies>
28 | 
29 |     <build>
30 |         <finalName>agent</finalName>
31 | 
32 |         <plugins>
33 |             <plugin>
34 |                 <groupId>org.apache.maven.plugins</groupId>
35 |                 <artifactId>maven-shade-plugin</artifactId>
36 |                 <version>2.4.1</version>
37 |                 <executions>
38 |                     <execution>
39 |                         <phase>package</phase>
40 |                         <goals>
41 |                             <goal>shade</goal>
42 |                         </goals>
43 |                         <configuration>
44 |                             <shadedArtifactAttached>false</shadedArtifactAttached>
45 |                             <createDependencyReducedPom>true</createDependencyReducedPom>
46 |                             <createSourcesJar>true</createSourcesJar>
47 |                             <shadeSourcesContent>true</shadeSourcesContent>
48 |                             <transformers>
49 |                                 <transformer
50 |                                         implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
51 |                                     <manifestEntries>
52 |                                         <Premain-Class>cn.iocoder.learning.bytebuddy.Agent</Premain-Class>
53 |                                     </manifestEntries>
54 |                                 </transformer>
55 |                             </transformers>
56 |                             <artifactSet>
57 |                                 <excludes>
58 |                                     <exclude>com.lmax:*</exclude>
59 |                                     <exclude>org.apache.httpcomponents:*</exclude>
60 |                                     <exclude>commons-logging:*</exclude>
61 |                                     <exclude>commons-codec:*</exclude>
62 |                                     <exclude>*:gson</exclude>
63 |                                     <exclude>io.grpc:*</exclude>
64 |                                     <exclude>io.netty:*</exclude>
65 |                                     <exclude>com.google.*:*</exclude>
66 |                                     <exclude>com.google.guava:guava</exclude>
67 |                                 </excludes>
68 |                             </artifactSet>
69 |                             <!--<relocations>-->
70 |                                 <!--<relocation>-->
71 |                                     <!--<pattern>${shade.net.bytebuddy.source}</pattern>-->
72 |                                     <!--<shadedPattern>${shade.net.bytebuddy.target}</shadedPattern>-->
73 |                                 <!--</relocation>-->
74 |                             <!--</relocations>-->
75 |                         </configuration>
76 |                     </execution>
77 |                 </executions>
78 |             </plugin>
79 |         </plugins>
80 |     </build>
81 | 
82 | </project>


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/bytebuddy/src/main/java/cn/iocoder/learning/bytebuddy/Agent.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning.bytebuddy;
 2 | 
 3 | import net.bytebuddy.agent.builder.AgentBuilder;
 4 | import net.bytebuddy.description.type.TypeDescription;
 5 | import net.bytebuddy.dynamic.DynamicType;
 6 | import net.bytebuddy.implementation.MethodDelegation;
 7 | import net.bytebuddy.matcher.ElementMatchers;
 8 | import net.bytebuddy.utility.JavaModule;
 9 | 
10 | import java.lang.instrument.Instrumentation;
11 | 
12 | public class Agent {
13 | 
14 |     public static void premain(String agentArgs, Instrumentation instrumentation) {
15 | 
16 |         System.out.println("一点不萌");
17 | 
18 |         new AgentBuilder.Default()
19 |                 .type(ElementMatchers.any())
20 |                 .transform(new AgentBuilder.Transformer() {
21 |                     public DynamicType.Builder<?> transform(DynamicType.Builder<?> builder, TypeDescription typeDescription, ClassLoader classLoader, JavaModule javaModule) {
22 |                         return builder
23 | //                                .method(ElementMatchers.any())
24 |                                 .method(ElementMatchers.named("hello"))
25 |                                 .intercept(MethodDelegation.to(MyServiceInterceptor.class))
26 |                                 ;
27 |                     }
28 |                 })
29 |                 .with(new AgentBuilder.Listener() {
30 |                     public void onDiscovery(String typeName, ClassLoader classLoader, JavaModule module, boolean loaded) {
31 | 
32 |                     }
33 | 
34 |                     public void onTransformation(TypeDescription typeDescription, ClassLoader classLoader, JavaModule module, boolean loaded, DynamicType dynamicType) {
35 |                         System.out.println("onTransformation ：" + typeDescription);
36 |                         System.out.println("onTransformation ：" + dynamicType);
37 |                     }
38 | 
39 |                     public void onIgnored(TypeDescription typeDescription, ClassLoader classLoader, JavaModule module, boolean loaded) {
40 | 
41 |                     }
42 | 
43 |                     public void onError(String typeName, ClassLoader classLoader, JavaModule module, boolean loaded, Throwable throwable) {
44 | 
45 |                     }
46 | 
47 |                     public void onComplete(String typeName, ClassLoader classLoader, JavaModule module, boolean loaded) {
48 | 
49 |                     }
50 |                 })
51 |                 .installOn(instrumentation);
52 | 
53 |         System.out.println("有一点萌");
54 |     }
55 | 
56 | }
57 | 


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/bytebuddy/src/main/java/cn/iocoder/learning/bytebuddy/Dog.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning.bytebuddy;
 2 | 
 3 | public class Dog {
 4 | 
 5 |     public int hello() {
 6 |         return 0;
 7 |     }
 8 | 
 9 | }
10 | 


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/bytebuddy/src/main/java/cn/iocoder/learning/bytebuddy/Example001.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning.bytebuddy;
 2 | 
 3 | import net.bytebuddy.ByteBuddy;
 4 | import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
 5 | import net.bytebuddy.implementation.FixedValue;
 6 | import net.bytebuddy.matcher.ElementMatchers;
 7 | 
 8 | public class Example001 {
 9 | 
10 |     public static void main(String[] args) throws IllegalAccessException, InstantiationException {
11 |         Class dynamicType = new ByteBuddy()
12 |                 .subclass(Object.class)
13 |                 .method(ElementMatchers.named("toString"))
14 | 
15 |                 .intercept(FixedValue.value("Hello World!"))
16 |                 .make()
17 |                 .load(Example001.class.getClassLoader(), ClassLoadingStrategy.Default.WRAPPER)
18 |                 .getLoaded();
19 |         Object s = dynamicType.newInstance();
20 |         System.out.println(s);
21 |     }
22 | 
23 | }
24 | 


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/bytebuddy/src/main/java/cn/iocoder/learning/bytebuddy/Example002.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning.bytebuddy;
 2 | 
 3 | import net.bytebuddy.ByteBuddy;
 4 | import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
 5 | import net.bytebuddy.implementation.MethodDelegation;
 6 | import net.bytebuddy.matcher.ElementMatchers;
 7 | 
 8 | public class Example002 {
 9 | 
10 |     public static void main(String[] args) throws IllegalAccessException, InstantiationException, NoSuchMethodException {
11 |         Class dynamicType = new ByteBuddy()
12 |                 .subclass(Dog.class)
13 |                 .method(ElementMatchers.named("hello"))
14 |                 .intercept(MethodDelegation.to(MyServiceInterceptor.class))
15 |                 .make()
16 |                 .load(Example002.class.getClassLoader(), ClassLoadingStrategy.Default.WRAPPER)
17 |                 .getLoaded();
18 | 
19 |         Object s = dynamicType.newInstance();
20 |         System.out.println(((Dog)s).hello());
21 |     }
22 | 
23 | }
24 | 


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/bytebuddy/src/main/java/cn/iocoder/learning/bytebuddy/IAnimal.java:
--------------------------------------------------------------------------------
1 | package cn.iocoder.learning.bytebuddy;
2 | 
3 | public interface IAnimal {
4 | }
5 | 


--------------------------------------------------------------------------------
/bytebuddy/src/main/java/cn/iocoder/learning/bytebuddy/MyServiceInterceptor.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning.bytebuddy;
 2 | 
 3 | import net.bytebuddy.implementation.bind.annotation.RuntimeType;
 4 | import net.bytebuddy.implementation.bind.annotation.SuperCall;
 5 | 
 6 | import java.util.concurrent.Callable;
 7 | 
 8 | public class MyServiceInterceptor {
 9 | 
10 |     @RuntimeType
11 |     public static Object intercept(@SuperCall Callable<?> zuper) throws Exception {
12 |         System.out.println("intercept：拦截了");
13 | 
14 | //        return zuper.call();
15 |         return 2;
16 |     }
17 | 
18 | }


--------------------------------------------------------------------------------
/bytebuddy/src/main/resources/META-INF/MANIFEST.MF:
--------------------------------------------------------------------------------
1 | Manifest-Version: 1.0
2 | Premain-Class: cn.iocoder.learning.bytebuddy.Agent
3 | Can-Redefine-Classes: true
4 | 


--------------------------------------------------------------------------------
/example01/pom.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <project xmlns="http://maven.apache.org/POM/4.0.0"
 3 |          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4 |          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5 |     <parent>
 6 |         <artifactId>parent</artifactId>
 7 |         <groupId>cn.iocoder.learning</groupId>
 8 |         <version>1.0-SNAPSHOT</version>
 9 |     </parent>
10 |     <modelVersion>4.0.0</modelVersion>
11 | 
12 |     <artifactId>example01</artifactId>
13 | 
14 | 
15 | </project>


--------------------------------------------------------------------------------
/example01/readme.md:
--------------------------------------------------------------------------------
1 | 简单的 JavaAgent 练手


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/example01/src/main/java/cn/iocoder/learning/Cat.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning;
 2 | 
 3 | public class Cat {
 4 | 
 5 |     public int hello() {
 6 |         return 2;
 7 |     }
 8 | 
 9 | }
10 | 


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/example01/src/main/java/cn/iocoder/learning/Dog.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning;
 2 | 
 3 | public class Dog {
 4 | 
 5 |     public int hello() {
 6 |         return 0;
 7 |     }
 8 | 
 9 | }
10 | 


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/example01/src/main/java/cn/iocoder/learning/Main.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning;
 2 | 
 3 | public class Main {
 4 | 
 5 |     public static void main(String[] args) {
 6 |         System.out.println("夜太黑");
 7 | 
 8 |         System.out.println(new Dog().hello());
 9 |     }
10 | 
11 | }
12 | 


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/javaagent01/pom.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <project xmlns="http://maven.apache.org/POM/4.0.0"
 3 |          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4 |          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5 |     <parent>
 6 |         <artifactId>parent</artifactId>
 7 |         <groupId>cn.iocoder.learning</groupId>
 8 |         <version>1.0-SNAPSHOT</version>
 9 |     </parent>
10 |     <modelVersion>4.0.0</modelVersion>
11 |     <packaging>jar</packaging>
12 | 
13 |     <artifactId>java-agent-01</artifactId>
14 | 
15 |     <build>
16 |         <finalName>agent</finalName>
17 | 
18 |         <plugins>
19 |             <plugin>
20 |                 <groupId>org.apache.maven.plugins</groupId>
21 |                 <artifactId>maven-jar-plugin</artifactId>
22 |                 <version>2.3.1</version>
23 |                 <configuration>
24 |                     <archive>
25 |                         <manifestFile>src/main/resources/META-INF/MANIFEST.MF</manifestFile>
26 |                     </archive>
27 |                 </configuration>
28 |             </plugin>
29 | 
30 |             <plugin>
31 |                 <artifactId>maven-assembly-plugin</artifactId>
32 |                 <configuration>
33 |                     <outputDirectory>${basedir}</outputDirectory>
34 |                     <archive>
35 |                         <index>true</index>
36 |                         <manifest>
37 |                             <addClasspath>true</addClasspath>
38 |                         </manifest>
39 |                         <manifestEntries>
40 |                             <Premain-Class>cn.iocoder.learning.javaagent01.Agent</Premain-Class>
41 |                         </manifestEntries>
42 |                     </archive>
43 |                     <descriptorRefs>
44 |                         <descriptorRef>jar-with-dependencies</descriptorRef>
45 |                     </descriptorRefs>
46 |                 </configuration>
47 |             </plugin>
48 |             <plugin>
49 |                 <groupId>org.apache.maven.plugins</groupId>
50 |                 <artifactId>maven-compiler-plugin</artifactId>
51 |                 <configuration>
52 |                     <source>1.7</source>
53 |                     <target>1.7</target>
54 |                 </configuration>
55 |             </plugin>
56 |         </plugins>
57 |     </build>
58 | 
59 | </project>


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/javaagent01/src/main/java/cn/iocoder/learning/javaagent01/Agent.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning.javaagent01;
 2 | 
 3 | import java.lang.instrument.Instrumentation;
 4 | 
 5 | public class Agent {
 6 | 
 7 | //    public static void premain(String agentArgs) {
 8 | //        System.out.println("我是一个萌萌哒的 Java Agent");
 9 | //        try {
10 | //            Thread.sleep(2000L);
11 | //        } catch (InterruptedException e) {
12 | //            e.printStackTrace();
13 | //        }
14 | //    }
15 | 
16 |     public static void premain(String agentArgs, Instrumentation instrumentation)  {
17 | 
18 |         instrumentation.addTransformer(new ClassFileTransformerDemo());
19 | 
20 |         System.out.println("一点不萌");
21 |     }
22 | 
23 | }
24 | 


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/javaagent01/src/main/java/cn/iocoder/learning/javaagent01/ClassFileTransformerDemo.java:
--------------------------------------------------------------------------------
 1 | package cn.iocoder.learning.javaagent01;
 2 | 
 3 | import java.io.File;
 4 | import java.io.FileInputStream;
 5 | import java.io.IOException;
 6 | import java.io.InputStream;
 7 | import java.lang.instrument.ClassFileTransformer;
 8 | import java.lang.instrument.IllegalClassFormatException;
 9 | import java.security.ProtectionDomain;
10 | 
11 | public class ClassFileTransformerDemo implements ClassFileTransformer {
12 | 
13 |     public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
14 |         System.out.println("className: " + className);
15 |         if (!className.equalsIgnoreCase("cn/iocoder/learning/Dog")) {
16 |             return null;
17 |         }
18 | //        return getBytesFromFile("cn/iocoder/learning/Cat");
19 |         return getBytesFromFile("/Users/yunai/Java/learning/example01/Dog.class");
20 |     }
21 | 
22 |     public static byte[] getBytesFromFile(String fileName) {
23 |         File file = new File(fileName);
24 |         try (InputStream is = new FileInputStream(file)) {
25 |             // precondition
26 | 
27 |             long length = file.length();
28 |             byte[] bytes = new byte[(int) length];
29 | 
30 |             // Read in the bytes
31 |             int offset = 0;
32 |             int numRead = 0;
33 |             while (offset <bytes.length
34 |                     && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
35 |                 offset += numRead;
36 |             }
37 | 
38 |             if (offset < bytes.length) {
39 |                 throw new IOException("Could not completely read file "
40 |                         + file.getName());
41 |             }
42 |             is.close();
43 |             return bytes;
44 |         } catch (Exception e) {
45 |             System.out.println("error occurs in _ClassTransformer!"
46 |                     + e.getClass().getName());
47 |             return null;
48 |         }
49 |     }
50 | 
51 | }
52 | 


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/javaagent01/src/main/resources/META-INF/MANIFEST.MF:
--------------------------------------------------------------------------------
1 | Manifest-Version: 1.0
2 | Premain-Class: cn.iocoder.learning.javaagent01.Agent
3 | Can-Redefine-Classes: true
4 | 


--------------------------------------------------------------------------------
/pom.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <project xmlns="http://maven.apache.org/POM/4.0.0"
 3 |          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4 |          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5 |     <modelVersion>4.0.0</modelVersion>
 6 | 
 7 |     <groupId>cn.iocoder.learning</groupId>
 8 |     <artifactId>parent</artifactId>
 9 |     <packaging>pom</packaging>
10 |     <version>1.0-SNAPSHOT</version>
11 |     <modules>
12 |         <module>javaagent01</module>
13 |         <module>example01</module>
14 |         <module>bytebuddy</module>
15 |     </modules>
16 | 
17 | </project>


--------------------------------------------------------------------------------