BCI - The Power of Bytecode Instrumentation in Java

public getValue()I
L0 (0)
LINENUMBER 28 L0
SIPUSH 1000
ISTORE 1
L1 (3)
LINENUMBER 29 L1
ILOAD 1
IRETURN
L2 (6)
LOCALVARIABLE this Lflowlite/io/ASMTest; L0 L2 0
LOCALVARIABLE value I L1 L2 1
MAXSTACK = 1
MAXLOCALS = 2

public int getValue() {
	int value = 1000;
	return value;
}

package java.lang;

// Referenced classes of package java.lang:
// Throwable, String

public class Exception extends Throwable {

	public Exception() {
	}

	public Exception(String s) {
		super(s);
	}

	public Exception(String s, Throwable throwable) {
		super(s, throwable);
	}

	public Exception(Throwable throwable) {
		super(throwable);
	}

	static final long serialVersionUID = 0xd0fd1f3e1a3b1cc4L;
}

/ class version 49.0 (49)
// access flags 33
public class Exception extends Throwable {


// access flags 24
final static long serialVersionUID = -3387516993124229948

// access flags 1
public () : void
ALOAD 0
INVOKESPECIAL Throwable.() : void
RETURN
MAXSTACK = 1
MAXLOCALS = 1

// access flags 1
public (String) : void
ALOAD 0
ALOAD 1
INVOKESPECIAL Throwable.(String) : void
RETURN
MAXSTACK = 2
MAXLOCALS = 2

// access flags 1
public (String,Throwable) : void
ALOAD 0
ALOAD 1
ALOAD 2
INVOKESPECIAL Throwable.(String,Throwable) : void
RETURN
MAXSTACK = 3
MAXLOCALS = 3

// access flags 1
public (Throwable) : void
ALOAD 0
ALOAD 1
INVOKESPECIAL Throwable.(Throwable) : void
RETURN
MAXSTACK = 2
MAXLOCALS = 2
}

public class Exception extends Throwable {

	public Exception() {
		ExceptionCallBack.exceptionOccurred(this);
	}

	public Exception(String s) {
		super(s);
		ExceptionCallBack.exceptionOccurred(this);
	}

	public Exception(String s, Throwable throwable) {
		super(s, throwable);
		ExceptionCallBack.exceptionOccurred(this);
	}

	public Exception(Throwable throwable) {
		super(throwable);
		ExceptionCallBack.exceptionOccurred(this);
	}

	static final long serialVersionUID = 0xd0fd1f3e1a3b1cc4L;
}

public Exception(String s)
{
	super(s);
	ExceptionCallBack.exceptionOccurred(this);
}

package flowlite.exception2;

import java.io.FileOutputStream;

import org.objectweb.asm.*;
import org.objectweb.asm.commons.*;

public class ExceptionTransformer implements Opcodes {

	// Convert class
	public void transform(String newClassName) throws Exception {

		System.out.println("Starting transformation of java.lang.Exception...");

		// Reader
		ClassReader reader = new ClassReader("java.lang.Exception");
		// Writer

		ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);

		// Class Adapter
		ClassAdapter adapter = new ExceptionClassAdapter(writer);

		reader.accept(adapter, ClassReader.SKIP_FRAMES);

		byte[] b = writer.toByteArray();
		FileOutputStream fos = new FileOutputStream(newClassName + ".class");
		fos.write(b);
		fos.flush();

	}

	public static void main(String[] args) {
		try {
			String newClassName = "Exception";
			if (args.length >= 1)
				newClassName = args[0];
			ExceptionTransformer fit = new ExceptionTransformer();
			fit.transform(newClassName);
		} catch (Exception ex) {
			ex.printStackTrace();
		}

	}
}

class ExceptionClassAdapter extends ClassAdapter implements Opcodes {

	public ExceptionClassAdapter(ClassVisitor visitor) {
		super(visitor);

	}

}

public class ExceptionTest2 {

	public static void doException(boolean bException) throws RuntimeException {
		if (bException)
			throw new RuntimeException("test");

	}

	public static void main(String[] args) {

		try {
			ExceptionTest2.doException(true); // <-- 여기서 Exception발생
		} catch (Exception ex) {
		}

		try {
			ExceptionTest2.doException(false);
		} catch (Exception ex) {
		}
	}
}

java -Xbootclasspath/p:./converted_classes ExcetpionTest2

ExceptionCallBack.exceptionOccurred(this);

package flowlite.exception2;

import java.io.FileOutputStream;

import org.objectweb.asm.*;
import org.objectweb.asm.commons.*;

public class ExceptionTransformer implements Opcodes {

	// Convert class
	public void transform(String newClassName) throws Exception {

		System.out.println("Starting transformation of java.lang.Exception...");

		ClassReader reader = new ClassReader("java.lang.Exception");
		ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
		ClassAdapter adapter = new ExceptionClassAdapter(writer);

		reader.accept(adapter, ClassReader.SKIP_FRAMES);

		byte[] b = writer.toByteArray();
		FileOutputStream fos = new FileOutputStream(newClassName + ".class");
		fos.write(b);
		fos.flush();

	}

	public static void main(String[] args) {
		try {
			String newClassName = "Exception";
			if (args.length >= 1)
				newClassName = args[0];
			ExceptionTransformer fit = new ExceptionTransformer();
			fit.transform(newClassName);
		} catch (Exception ex) {
			ex.printStackTrace();
		}

	}
}

class ExceptionClassAdapter extends ClassAdapter implements Opcodes {

	public ExceptionClassAdapter(ClassVisitor visitor) {
		super(visitor);

	}

	public MethodVisitor visitMethod(int access, String name, String desc, String sig, String[] exes) {
		MethodVisitor mv = super.visitMethod(access, name, desc, sig, exes);

		if (name.equals("")) { // Constructor
			System.out.println("Redefine Constructor...");
			ExceptionConstructorAdviceAdapter ecaa = new ExceptionConstructorAdviceAdapter(access, name, desc, mv);
			return ecaa;
		}

		return mv;

	}
}

class ExceptionConstructorAdviceAdapter extends AdviceAdapter {

	public ExceptionConstructorAdviceAdapter(int access, String name, String desc, MethodVisitor mv) {
		super(mv, access, name, desc);
	}

	protected void onMethodEnter() {

	}

	protected void onMethodExit(int opcode) {
		if (opcode == RETURN) {
			mv.visitVarInsn(ALOAD, 0);
			mv.visitMethodInsn(INVOKESTATIC, "flowlite/exception2/ExceptionCallBack", "exceptionOccurred", "(Ljava/lang/Exception;)V");
			mv.visitEnd();
		}
	}

}

protected void onMethodExit(int opcode) {
	if(opcode == RETURN) {
			mv.visitVarInsn(ALOAD, 0);
			mv.visitMethodInsn(INVOKESTATIC, "flowlite/exception2/ExceptionCallBack", "exceptionOccurred", "(Ljava/lang/Exception;)V");
			mv.visitEnd();
	}
}

// class version 49.0 (49)
// access flags 33
public class Exception extends Throwable {

// access flags 24
final static long serialVersionUID = -3387516993124229948

// access flags 1
public () : void
ALOAD 0
INVOKESPECIAL Throwable.() : void
ALOAD 0
INVOKESTATIC ExceptionCallBack.exceptionOccurred(Exception) : void
RETURN
MAXSTACK = 1
MAXLOCALS = 1

// access flags 1
public (String) : void
ALOAD 0
ALOAD 1
INVOKESPECIAL Throwable.(String) : void
ALOAD 0
INVOKESTATIC ExceptionCallBack.exceptionOccurred(Exception) : void
RETURN
MAXSTACK = 2
MAXLOCALS = 2

// access flags 1
public (String,Throwable) : void
ALOAD 0
ALOAD 1
ALOAD 2
INVOKESPECIAL Throwable.(String,Throwable) : void
ALOAD 0
INVOKESTATIC ExceptionCallBack.exceptionOccurred(Exception) : void
RETURN
MAXSTACK = 3
MAXLOCALS = 3

// access flags 1
public (Throwable) : void
ALOAD 0
ALOAD 1
INVOKESPECIAL Throwable.(Throwable) : void
ALOAD 0
INVOKESTATIC ExceptionCallBack.exceptionOccurred(Exception) : void
RETURN
MAXSTACK = 2
MAXLOCALS = 2
}

package flowlite.exception2;

public class ExceptionCallBack {

	public static void exceptionOccurred(Exception ex) {
		System.out.println("Oops~ " + ex + " has occurred...");
		ex.printStackTrace();
	}
}

java -Xbootclasspath/p:./converted_classes ExcetpionTest2

public InputStream getInputStream()throws IOException
public OutputStream getOutputStream()throws IOException

public int read(byte[]b,intoff,intlen)throws IOException

public InputStream getInputStream() {
	// 원래의 getInputStream(이름이 __orig$getInputStream__으로 바뀐)을 호출해서 InputStream을 얻어온다.
	InputStream is = __orig$getInputStream__();
	// 이 InputStream을 이용해서 나만의 InputStream을 만들어준다.
	FlowLiteSocketInputStream fsis = new FlowLiteSocketInputStream(this, is);

	return fsis;
}

package java.net;

public class FlowLiteSocketInputStream extends InputStream {

	Socket s = null;
	InputStream is = null;

	public FlowLiteSocketInputStream(Socket s, InputStream is) {
		this.s = s;
		this.is = is;
		SocketIOCallBack.createCalled(this);
	}

	public int read() throws IOException {
		int len = is.read();
		SocketIOCallBack.readCalled(this, 4);

		return len;

	}

	public int read(byte[] b) throws IOException {
		int len = is.read(b);
		SocketIOCallBack.readCalled(this, len);
		return len;
	}

	public int read(byte[] b, int off, int len) throws IOException {
		int len2 = is.read(b, off, len);
		SocketIOCallBack.readCalled(this, len2);
		return len2;
	}

	public int available() throws IOException {
		return is.available();
	}

	public void close() throws IOException {
		is.close();
	}

	public void mark(int readlimit) {
		is.mark(readlimit);
	}

	public boolean markSupported() {
		return is.markSupported();
	}

	public Socket getSocket() {
		return this.s;
	}
}

package flowlite.net;

import java.io.*;
import org.objectweb.asm.*;
import org.objectweb.asm.commons.*;

/**
 * Net io class transformer. Execute byte code transformation to convert
 * NetInputStream class You must convert native java.io.Socket class using this
 * class
 * 
 * The technique is the most powerful. So keep in mind~~
 * 
 * Must use ASM 3.0 library
 * 
 * @history 2007/07/17Dongwook ChoInitial Coding
 *
 */
public class SocketTransformer implements Opcodes {

	public SocketTransformer() {

	}

	// Convert class
	public void transform(String newClassName) throws Exception {
		System.out.println("Starting transformation of java.net.Socket...");
		// Prepared reader, writer, adapter

		ClassReader reader = new ClassReader("java.net.Socket");
		ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
		ClassAdapter adapter = new SocketClassAdapter(writer);

		reader.accept(adapter, ClassReader.SKIP_DEBUG);

		byte[] b = writer.toByteArray();
		FileOutputStream fos = new FileOutputStream(newClassName + ".class");
		fos.write(b);
		fos.flush();
	}

	public static void main(String[] args) {
		try {
			String newClassName = "Socket";
			if (args.length >= 1)
				newClassName = args[0];
			SocketTransformer fit = new SocketTransformer();
			fit.transform(newClassName);
		} catch (Exception ex) {
			ex.printStackTrace();
		}

	}
}

// Socket Class 변환기
class SocketClassAdapter extends ClassAdapter implements Opcodes {

	public SocketClassAdapter(ClassVisitor cv) {
		super(cv);
	}

	// 각메소드를 방문하면서 필요하면 변경한다.
	public MethodVisitor visitMethod(int access, String name, String descriptor, String signature,
			String[] exceptions) {

		if (name.equals("getInputStream")) {
			// getInputStream을 __orig$getInputStreram__ 으로 변경한다.

			System.out.println("Rename getInputStream to __orig$getInputStream__");
			MethodVisitor mv = cv.visitMethod(ACC_PUBLIC,

					"__orig$getInputStream__", "()Ljava/io/InputStream;", null, new String[] { "java/io/IOException" });
			mv.visitCode();
			mv.visitEnd();

			return mv;
		}

		return super.visitMethod(access, name, descriptor, signature, exceptions);
	}

	// 새로운getInputStream 메소드를 추가한다.

	public void visitEnd() {
		MethodVisitor mv = cv.visitMethod(ACC_PUBLIC, "getInputStream", "()Ljava/io/InputStream;",

				null, new String[] { "java/io/IOException" });

		mv.visitCode();
		mv.visitTypeInsn(NEW, "java/net/FlowLiteSocketInputStream");
		mv.visitInsn(DUP);
		mv.visitVarInsn(ALOAD, 0);
		mv.visitVarInsn(ALOAD, 0);

		// 원래메소드를 호출하고,
		mv.visitMethodInsn(INVOKEVIRTUAL, "java/net/Socket", "__orig$getInputStream__", "()Ljava/io/InputStream;");
		mv.visitMethodInsn(INVOKESPECIAL, "jav`a/net/FlowLiteSocketInputStream",

				"", "(Ljava/net/Socket;Ljava/io/InputStream;)V");
		mv.visitInsn(ARETURN);
		mv.visitMaxs(4, 1);
		mv.visitEnd();

	}
}

[Socket Info] Thread id = 20, Host name =localhost:10583, Status = 1, Access time = Fri Aug 10 18:11:06 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Fri Aug 10 18:11:06 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Fri Aug 10 18:11:06 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Fri Aug 10 18:11:06 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Fri Aug 10 18:11:06 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Fri Aug 10 18:11:06 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Fri Aug 10 18:11:06 KST 2007
....

[Net IO], Thread id = 20, Bytes read = 736, Access time = Fri Aug 10 18:11:06 KST 2007

Prompt> java

....

-agentlib:[=]
load native agent library , e.g. -agentlib:hprof
see also, -agentlib:jdwp=help and -agentlib:hprof=help
-agentpath:[=]
load native agent library by full pathname
-javaagent:[=]
load Java programming language agent, see java.lang.instrument

public class SimpleProfiler implements ClassFileTransformer {

	public SimpleProfiler() {
		super();
	}

	public static void premain(String args, Instrumentation inst) {
		try {
			// Redefine preloadedclasses. Especially rt.jar boot class
			ArrayList defs = new ArrayList();
			for( Class c : inst.getAllLoadedClasses()) {
				try {
					if(c.getName().equals("java.io.File")) { // 여기서는 샘플로 java.io.File 만 변환한다.
						System.out.println("Redefining class " + c.getName());
						ClassReader reader = new ClassReader(c.getName());
						ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS+ClassWriter.COMPUTE_FRAMES);

						// 여기가 구현부. ASM 라이브러리를 이용한다.
						// --> 여기서는 소스를제공하지 않으며, 내부적으로 모든 클래스의 메소드의 시작점과 끝점에
						// --> Method Start와 Method End를 알리는 코드를 삽입한다.
						
						ClassAdapter adapter = new SimpleClassAdapter(writer, c.getName));
						reader.accept(adapter, ClassReader.SKIP_DEBUG);
						
						byte[] result = writer.toByteArray();
						if(result != null) defs.add(new ClassDefinition(c, result));
					}
				} catch(Exception ex) {
					ex.printStackTrace();
				}
			}
			
			ClassDefinition[] cdef = defs.toArray(new ClassDefinition[defs.size()]);
			inst.redefineClasses(cdef);
			inst.addTransformer(new SimpleProfiler());
			(new Thread(new MonitoringThread())).start();
		} catch(Exception ex) {
			ex.printStackTrace();
		}
	}

	public byte[] transform(ClassLoader l, String className, Class c, ProtectionDomain pd, byte[] b)
			throws IllegalClassFormatException {

		if (l != ClassLoader.getSystemClassLoader()) {
			return b;
		}

		if (className.startsWith("instrument/profiler")) {
			return b;
		}

		System.out.println("Classloader = " + l);
		System.out.println("Class = " + className);

		byte[] result = b;
		ClassReader reader = new ClassReader(b);
		ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
		ClassAdapter adapter = new SimpleClassAdapter(writer, className); // 여기가 구현부...
		reader.accept(adapter, ClassReader.SKIP_DEBUG);

		result = writer.toByteArray();

		return result;

	}
}

Premain-Class: instrument.profiler.SimpleProfiler
Can-Redefine-Classes: True
Boot-Class-Path: profiler.jar;asm-3.0.jar

java -javaagent:profiler.jar [Your Target Applicatin]

---------- Call Table -------------------------------
instrument/target/RunThread.do31179[4694]
instrument/target/RunThread.do2791[5730]
instrument/target/RunThread.do1396[3189]
java.io.File.14[0]
java.io.File.getPath8[0]
java.io.File.exists6[0]
instrument/target/RunThread.5[0]
java.io.File.lastModified4[0]
java.io.File.length2[0]
java.io.File.getPrefixLength2[0]
java.io.File.getCanonicalPath2[0]
instrument/target/ProfilerTarget.main1[0]

--------------------[Exception Tracking]--------------------
Exception count = 9
[Exception] Exception = java.io.IOException, Message = Something Bad2~~, Thread id = 11, Caller = [Sigature]flowlite.server.ExceptionGenerator.doSomething2, Called from = [Sigature]flowlite.server.ExceptionGenerator.doSomething2, When = Mon Aug 13 11:06:10 KST 2007
flowlite.server.ExceptionGenerator.doSomething2(FlowLiteMBeanServer.java:128)
flowlite.server.ExceptionGenerator.run(FlowLiteMBeanServer.java:113)
java.lang.Thread.run(Unknown Source)

[Exception] Exception = java.io.IOException, Message = Something Bad2~~, Thread id = 11, Caller = [Sigature]flowlite.server.ExceptionGenerator.doSomething2, Called from = [Sigature]flowlite.server.ExceptionGenerator.run, When = Mon Aug 13 11:06:10 KST 2007
flowlite.server.ExceptionGenerator.doSomething2(FlowLiteMBeanServer.java:128)
flowlite.server.ExceptionGenerator.run(FlowLiteMBeanServer.java:113)
java.lang.Thread.run(Unknown Source)

...


--------------------[Active Thread & Call Tree Tracking]--------------------
Thread count = 26
[ActiveThread] Thread id = 62, Thread name = Thread-49, Group name = main
[Call Tree]
[Call][Sigature]flowlite.server.CallTreeGenerator$InnerGenerator.depth1_1, duration = 31[ms]
[Call][Sigature]java.util.Random.nextLong, duration = 0[ms]
[Call][Sigature]java.lang.Math.abs, duration = 0[ms]
[Call][Sigature]java.lang.Thread.sleep, duration = 0[ms]
[Call][Sigature]flowlite.server.CallTreeGenerator$InnerGenerator.depth2_1, duration = 15[ms]
[Call][Sigature]java.util.Random.nextLong, duration = 0[ms]
[Call][Sigature]java.lang.Math.abs, duration = 0[ms]
[Call][Sigature]java.lang.Thread.sleep, duration = 15[ms]

...



--------------------[File I/O Tracking]--------------------
File I/O count = 22
[File Info] Thread id = 22, File name = c:test.txt, Status = 2, File mode = [r+w], read time = Mon Aug 13 11:06:15 KST 2007
[File IO], Thread id = 22, File name =c:test.txt, Bytes read = 1024, Access time = Mon Aug 13 11:06:15 KST 2007
[File IO], Thread id = 22, File name =c:test.txt, Bytes read = 1024, Access time = Mon Aug 13 11:06:15 KST 2007
...


Socket Info] Thread id = 20, Host name =localhost:17904, Status = 1, Access time = Mon Aug 13 11:06:13 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Mon Aug 13 11:06:13 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Mon Aug 13 11:06:13 KST 2007
[Net IO], Thread id = 20, Bytes read = 1024, Access time = Mon Aug 13 11:06:13 KST 2007

...


--------------------[JDBC I/O Tracking]--------------------
Connection count = 1
Statement count = 1
FetchCount count = 100
[Connection] Statement count = 10, DB = Oracle, Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options, Created = 2007-08-13
[Statement] Query = SELECT name FROM t_pstmt_test WHERE id = ?, Execution count = 10, Fetch size = 10, Statement Type = Prepared
[Execution] Column Count = 1, Fetch count = 1, {Parameters} = (1, 4), 
[Fetch] Fetched value count = 1
(1, name4),

...