Package org.aspectj.weaver.tools

Class WeavingAdaptor

java.lang.Object

org.aspectj.weaver.tools.WeavingAdaptor

All Implemented Interfaces:

IMessageContext

Direct Known Subclasses:

ClassLoaderWeavingAdaptor

public class WeavingAdaptor
extends Object
implements IMessageContext

This adaptor allows the AspectJ compiler to be embedded in an existing system to facilitate load-time weaving. It provides an interface for a weaving class loader to provide a classpath to be woven by a set of aspects. A callback is supplied to allow a class loader to define classes generated by the compiler during the weaving process.

A weaving class loader should create a WeavingAdaptor before any classes are defined, typically during construction. The set of aspects passed to the adaptor is fixed for the lifetime of the adaptor although the classpath can be augmented. A system property can be set to allow verbose weaving messages to be written to the console.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	WeavingAdaptor.WeavingAdaptorMessageHolder	Processes messages arising from weaver operations.
protected class	WeavingAdaptor.WeavingAdaptorMessageWriter

Field Summary

Fields

Modifier and Type	Field	Description
protected ProtectionDomain	activeProtectionDomain
protected BcelWorld	bcelWorld
protected WeavedClassCache	cache
BcelObjectType	delegateForCurrentClass
protected Map<String,IUnwovenClassFile>	generatedClasses
protected GeneratedClassHandler	generatedClassHandler
static final String	SHOW_WEAVE_INFO_PROPERTY
static final String	TRACE_MESSAGES_PROPERTY
protected boolean	verbose
protected BcelWeaver	weaver
static final String	WEAVING_ADAPTOR_VERBOSE	System property used to turn on verbose weaving messages

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	WeavingAdaptor()
	WeavingAdaptor(GeneratedClassHandler handler, URL[] classURLs, URL[] aspectURLs)	Construct a WeavingAdaptor with a reference to a GeneratedClassHandler, a full search path for resolving classes and a complete set of aspects.
	WeavingAdaptor(WeavingClassLoader loader)	Construct a WeavingAdaptor with a reference to a weaving class loader.

Method Summary

Modifier and Type	Method	Description
protected boolean	accept(String name, byte[] bytes)
void	addURL(URL url)	Appends URL to path used by the WeavingAdptor to resolve classes
protected void	createMessageHandler()
protected boolean	debug(String message)
protected void	disable()
protected void	dump(String name, byte[] b, boolean before)	Dump the given bytcode in _dump/...
protected void	enable()
protected void	ensureDelegateInitialized(String name, byte[] bytes)
protected boolean	error(String message)
protected boolean	error(String message, Throwable th)
String	getContextId()
protected String	getDumpDir()
protected List<String>	getFullClassPath(ClassLoader loader)
protected IMessageHandler	getMessageHandler()
IMessageHolder	getMessageHolder()
protected boolean	info(String message)
protected void	initializeCache(ClassLoader loader, List<String> aspects, GeneratedClassHandler existingClassHandler, IMessageHandler myMessageHandler)	If the cache is enabled, initialize it and swap out the existing classhandler for the caching one -
protected boolean	isEnabled()
void	setActiveProtectionDomain(ProtectionDomain protectionDomain)
protected void	setMessageHandler(IMessageHandler mh)
protected boolean	shouldDump(String name, boolean before)
protected boolean	warn(String message)
protected boolean	warn(String message, Throwable th)
byte[]	weaveClass(String name, byte[] bytes)	Weave a class using aspects previously supplied to the adaptor.
byte[]	weaveClass(String name, byte[] bytes, boolean mustWeave)	Weave a class using aspects previously supplied to the adaptor.

Methods inherited from class java.lang.Object

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

Field Details

WEAVING_ADAPTOR_VERBOSE

public static final String WEAVING_ADAPTOR_VERBOSE

System property used to turn on verbose weaving messages

See Also:

• Constant Field Values

SHOW_WEAVE_INFO_PROPERTY

public static final String SHOW_WEAVE_INFO_PROPERTY

See Also:

• Constant Field Values

TRACE_MESSAGES_PROPERTY

public static final String TRACE_MESSAGES_PROPERTY

See Also:

• Constant Field Values

verbose

protected boolean verbose

bcelWorld

protected BcelWorld bcelWorld

weaver

protected BcelWeaver weaver

generatedClassHandler

protected GeneratedClassHandler generatedClassHandler

generatedClasses

protected Map<String,IUnwovenClassFile> generatedClasses

delegateForCurrentClass

public BcelObjectType delegateForCurrentClass

activeProtectionDomain

protected ProtectionDomain activeProtectionDomain

cache

protected WeavedClassCache cache

Constructor Details

WeavingAdaptor

protected WeavingAdaptor()

WeavingAdaptor

public WeavingAdaptor(WeavingClassLoader loader)

Construct a WeavingAdaptor with a reference to a weaving class loader. The adaptor will automatically search the class loader hierarchy to resolve classes. The adaptor will also search the hierarchy for WeavingClassLoader instances to determine the set of aspects to be used for weaving.

Parameters:

loader - instance of ClassLoader

WeavingAdaptor

public WeavingAdaptor(GeneratedClassHandler handler,
 URL[] classURLs,
 URL[] aspectURLs)

Construct a WeavingAdaptor with a reference to a GeneratedClassHandler, a full search path for resolving classes and a complete set of aspects. The search path must include classes loaded by the class loader constructing the WeavingAdaptor and all its parents in the hierarchy.

Parameters:

handler - GeneratedClassHandler

classURLs - the URLs from which to resolve classes

aspectURLs - the aspects used to weave classes defined by this class loader

Method Details

getFullClassPath

protected List<String> getFullClassPath(ClassLoader loader)

initializeCache

protected void initializeCache(ClassLoader loader,
 List<String> aspects,
 GeneratedClassHandler existingClassHandler,
 IMessageHandler myMessageHandler)

If the cache is enabled, initialize it and swap out the existing classhandler for the caching one -

Parameters:

loader - classloader for this adapter, may be null

aspects - List of strings representing aspects managed by the adapter; these could be urls or classnames

existingClassHandler - current class handler

myMessageHandler - current message handler

createMessageHandler

protected void createMessageHandler()

getMessageHandler

protected IMessageHandler getMessageHandler()

getMessageHolder

public IMessageHolder getMessageHolder()

setMessageHandler

protected void setMessageHandler(IMessageHandler mh)

disable

protected void disable()

enable

protected void enable()

isEnabled

protected boolean isEnabled()

addURL

public void addURL(URL url)

Appends URL to path used by the WeavingAdptor to resolve classes

Parameters:

url - to be appended to search path

weaveClass

public byte[] weaveClass(String name,
 byte[] bytes)
                  throws IOException

Weave a class using aspects previously supplied to the adaptor.

Parameters:

name - the name of the class

bytes - the class bytes

Returns:

the woven bytes

Throws:

IOException - weave failed

weaveClass

public byte[] weaveClass(String name,
 byte[] bytes,
 boolean mustWeave)
                  throws IOException

Weave a class using aspects previously supplied to the adaptor.

Parameters:

name - the name of the class in the internal form of fully qualified class and interface names as defined in The Java Virtual Machine Specification. For example, "java/util/List".

bytes - the input byte buffer in class file format - must not be modified

mustWeave - if true then this class must get woven (used for concrete aspects generated from XML)

Returns:

a well-formed class file buffer (the weaving result), or null if no weaving was performed

Throws:

IOException - weave failed

See Also:

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

accept

protected boolean accept(String name,
 byte[] bytes)

shouldDump

protected boolean shouldDump(String name,
 boolean before)

ensureDelegateInitialized

protected void ensureDelegateInitialized(String name,
 byte[] bytes)

debug

protected boolean debug(String message)

info

protected boolean info(String message)

warn

protected boolean warn(String message)

warn

protected boolean warn(String message,
 Throwable th)

error

protected boolean error(String message)

error

protected boolean error(String message,
 Throwable th)

getContextId

public String getContextId()

Specified by:

getContextId in interface IMessageContext

dump

protected void dump(String name,
 byte[] b,
 boolean before)

Dump the given bytcode in _dump/... (dev mode)

Parameters:

name -

b -

before - whether we are dumping before weaving

getDumpDir

protected String getDumpDir()

Returns:

the directory in which to dump - default is _ajdump but it

setActiveProtectionDomain

public void setActiveProtectionDomain(ProtectionDomain protectionDomain)