classUtils.javassist.sample.evolve
Class Evolution

java.lang.Object
  classUtils.javassist.sample.evolve.Evolution

All Implemented Interfaces:

Translator

public class Evolution
extends java.lang.Object
implements Translator

Evolution provides a set of methods for instrumenting bytecodes. For class evolution, updatable class A is renamed to B. Then an abstract class named A is produced as the super class of B. If the original class A has a public method m(), then the abstract class A has an abstract method m(). abstract class A abstract m() _makeInstance() | class A --------> class B m() m() Also, all the other classes are translated so that "new A(i)" in the methods is replaced with "_makeInstance(i)". This makes it possible to change the behavior of the instantiation of the class A.

Field Summary

static java.lang.String	handlerMethod
static java.lang.String	latestVersionField
static java.lang.String	versionManagerMethod

Constructor Summary

Evolution()

Method Summary

void	makeUpdatable(java.lang.String classname)
void	onWrite(ClassPool _pool, java.lang.String classname) Is invoked by a ClassPool for notifying that a class is written out to an output stream.
void	start(ClassPool _pool) Is invoked by a ClassPool for initialization when the object is attached to a ClassPool object.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

handlerMethod

public static final java.lang.String handlerMethod

See Also:

Constant Field Values

latestVersionField

public static final java.lang.String latestVersionField

See Also:

Constant Field Values

versionManagerMethod

public static final java.lang.String versionManagerMethod

See Also:

Constant Field Values

Constructor Detail

Evolution

public Evolution()

Method Detail

start

public void start(ClassPool _pool)
           throws NotFoundException

Description copied from interface: Translator

Is invoked by a ClassPool for initialization when the object is attached to a ClassPool object.

Specified by:

start in interface Translator

Parameters:

_pool - the ClassPool that this translator is attached to.

Throws:

NotFoundException

See Also:

ClassPool.ClassPool(ClassPool,Translator), ClassPool.getDefault(Translator)

onWrite

public void onWrite(ClassPool _pool,
                    java.lang.String classname)
             throws NotFoundException,
                    CannotCompileException

Description copied from interface: Translator

Is invoked by a ClassPool for notifying that a class is written out to an output stream.

If CtClass.frozen() is true, that is, if the class has been already modified and written, then onWrite() is not invoked.

Specified by:

onWrite in interface Translator

Parameters:

_pool - the ClassPool that this translator is attached to.

classname - a fully-qualified class name

Throws:

NotFoundException

CannotCompileException

See Also:

ClassPool.writeFile(String), ClassPool.writeFile(String, String), ClassPool.write(String), ClassPool.write(String,DataOutputStream)

makeUpdatable

public void makeUpdatable(java.lang.String classname)
                   throws NotFoundException,
                          CannotCompileException

Throws:

NotFoundException

CannotCompileException