org.hotswap.agent.util

Class HotswapTransformer

java.lang.Object

org.hotswap.agent.util.HotswapTransformer

All Implemented Interfaces:

ClassFileTransformer

public class HotswapTransformer
extends Object
implements ClassFileTransformer

Java instrumentation transformer.

The is the single instance of transformer registered by HotswapAgent. It will delegate to plugins to do the transformer work.

Author:

Jiri Bubnik

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<ClassFileTransformer,ClassLoader>	classLoaderTransformers
protected Map<String,org.hotswap.agent.util.HotswapTransformer.RegisteredTransformersRecord>	registeredTransformers
protected Map<ClassLoader,Object>	seenClassLoaders

Constructor Summary

Constructors

Constructor and Description
HotswapTransformer()

Method Summary

Modifier and Type	Method and Description
void	closeClassLoader(ClassLoader classLoader) Remove all transformers registered with a classloader
protected void	ensureClassLoaderInitialized(ClassLoader classLoader, ProtectionDomain protectionDomain) Every classloader should be initialized.
protected String	normalizeTypeRegexp(String registeredType) Transform type to ^regexp$ form - match only whole pattern.
void	registerTransformer(ClassLoader classLoader, String classNameRegexp, ClassFileTransformer transformer) Register a transformer for a regexp matching class names.
void	removeTransformer(String classNameRegexp, ClassFileTransformer transformer) Remove registered transformer.
void	setExcludedClassLoaderPatterns(List<Pattern> excludedClassLoaderPatterns)
byte[]	transform(ClassLoader classLoader, String className, Class<?> redefiningClass, ProtectionDomain protectionDomain, byte[] bytes) Main transform method called by Java instrumentation.

Methods inherited from class java.lang.Object

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

Field Detail

registeredTransformers

protected Map<String,org.hotswap.agent.util.HotswapTransformer.RegisteredTransformersRecord> registeredTransformers

classLoaderTransformers

protected Map<ClassFileTransformer,ClassLoader> classLoaderTransformers

seenClassLoaders

protected Map<ClassLoader,Object> seenClassLoaders

Constructor Detail

HotswapTransformer

public HotswapTransformer()

Method Detail

setExcludedClassLoaderPatterns

public void setExcludedClassLoaderPatterns(List<Pattern> excludedClassLoaderPatterns)

Parameters:

excludedClassLoaderPatterns - the excludedClassLoaderPatterns to set

registerTransformer

public void registerTransformer(ClassLoader classLoader,
                                String classNameRegexp,
                                ClassFileTransformer transformer)

Register a transformer for a regexp matching class names. Used by OnClassLoadEvent annotation respective OnClassLoadedHandler.

Parameters:

classLoader - the classloader to which this transformation is associated

classNameRegexp - regexp to match fully qualified class name. Because "." is any character in regexp, this will match / in the transform method as well (diffentence between java/lang/String and java.lang.String).

transformer - the transformer to be called for each class matching regexp.

removeTransformer

public void removeTransformer(String classNameRegexp,
                              ClassFileTransformer transformer)

Remove registered transformer.

Parameters:

classNameRegexp - regexp to match fully qualified class name.

transformer - currently registered transformer

closeClassLoader

public void closeClassLoader(ClassLoader classLoader)

Remove all transformers registered with a classloader

Parameters:

classLoader -

transform

public byte[] transform(ClassLoader classLoader,
                        String className,
                        Class<?> redefiningClass,
                        ProtectionDomain protectionDomain,
                        byte[] bytes)
                 throws IllegalClassFormatException

Main transform method called by Java instrumentation.

It does not do the instrumentation itself, instead iterates registered transformers and compares registration class regexp - if the regexp matches, the classloader is called.

Note that class bytes may be send to multiple transformers, but the order is not defined.

Specified by:

transform in interface ClassFileTransformer

Throws:

IllegalClassFormatException

See Also:

ClassFileTransformer.transform(ClassLoader, String, Class, java.security.ProtectionDomain, byte[])

ensureClassLoaderInitialized

protected void ensureClassLoaderInitialized(ClassLoader classLoader,
                                            ProtectionDomain protectionDomain)

Every classloader should be initialized. Usually if anything interesting happens, it is initialized during plugin initialization process. However, some plugins (e.g. Hotswapper) are triggered during classloader initialization process itself (@Init on static method). In this case, the plugin will be never invoked, until the classloader initialization is invoked from here. Schedule with some timeout to allow standard plugin initialization process to precede.

Parameters:

classLoader - the classloader to which this transformation is associated

protectionDomain - associated protection domain (if any)

normalizeTypeRegexp

protected String normalizeTypeRegexp(String registeredType)

Transform type to ^regexp$ form - match only whole pattern.

Parameters:

registeredType - type

Returns: