File	Doc	Category	Size	Date	Package
Instrumentation.java	API Doc	Android 1.5 API	9026	Wed May 06 22:41:02 BST 2009	java.lang.instrument

Instrumentation

Fields Summary

Constructors Summary

Methods Summary
public void	addTransformer(java.lang.instrument.ClassFileTransformer transformer) Registers the supplied transformer argument with the VM. Any classes that are to be defined or re-defined (if supported) in the VM will then be offered to the transformer for it to carry out any byte code modifications. The exception to this scheme is if the class to be defined / re-defined is a dependency of the transformer. This operation can be carried out multiple times on a concrete Instrumentation. The order of registration is important as it defines the order in which the transformers' transformation operation gets called. It is possible for any given instance of ClassFileTransformer to be registered more than once with this operation. param transformer a class file transformer throws NullPointerException if transformer is null.
public java.lang.Class[]	getAllLoadedClasses() Returns an array of all of the classes that have been loaded into the VM. return an array of Class objects with each element identifying a class that has been loaded into the VM.
public java.lang.Class[]	getInitiatedClasses(java.lang.ClassLoader loader) Returns an array of all of the classes for which loader is the initiating class loader. param loader a class loader. In order to obtain the array of classes initiated by the bootstrap class loader this argument should be null. return an array of Class objects with each element identifying a class that has been initiated by the specified class loader.
public long	getObjectSize(java.lang.Object objectToSize) Returns the number of bytes in memory required by this VM for the supplied object objectToSize. The returned value should be taken as an estimation only which is susceptible to change between separate launches of the VM. param objectToSize any object return an approximation of the number of bytes in memory taken up by objectToSize. throws NullPointerException if the given object is null.
public boolean	isRedefineClassesSupported() Returns a boolean indication of whether or not this VM supports the on-the-fly redefining of classes that have been already loaded. return true if class redefining is supported, otherwise false.
public void	redefineClasses(java.lang.instrument.ClassDefinition[] definitions) Receives an array of {@link ClassDefinition} instances and attempts to carry out on-the-fly redefining on each of the associated classes. Redefining in this manner may be used to update the following parts of an already loaded class: attributes constant pool method implementations If any invocations of a redefined method are already active in the VM when this call is made then they will run to completion and be unaffected by the outcome of this method. Provided the method redefinition is successful, all subsequent calls on the method will run the new version. Redefining a class may not be used to make changes to any other aspects of a previously loaded class such as its inheritance hierarchy, the names or signatures of any of its methods, the names of any fields, the values of any static variables etc. If a class associated with a ClassDefinition is successfully redefined then there will be no resulting re-run of any of its initialization code. Similarly, any instances of the class that were created before the redefining will not be changed in any way. That is, they will remain in the VM as instances of the previous version of the class. Note that before the requested redefinitions are attempted, each {@link ClassFileTransformer} registered with the VM will be given the opportunity to carry out their own custom transformations of the new version of the class. param definitions an array of ClassDefinition objects wrapping the details of the classes to be redefined. A zero-length array value will not cause an error but, instead, will silently do nothing. throws ClassNotFoundException if any of the classes specified in the contents of definitions cannot be located. throws UnmodifiableClassException if any of the classes specified in the contents of definitions cannot be modified. throws UnsupportedOperationException if this method is not supported in by the VM. May be checked in advance by calling {@link #isRedefineClassesSupported()}. throws ClassFormatError if any of the definitions elements has been created with a byte array containing a badly formed class file. throws NoClassDefFoundError if there is disagreement between the name of a class to be redefined and the name of the class from the corresponding class file format byte array. throws UnsupportedClassVersionError if the version of any of the classes to be redefined is not supported by the VM. throws ClassCircularityError if a circular dependency is detected among the classes to be redefined. throws LinkageError if a linkage error situation is detected such that there is an incompatability between dependent classes. throws NullPointerException if definitions or any of its elements are found to be null. see #isRedefineClassesSupported()
public boolean	removeTransformer(java.lang.instrument.ClassFileTransformer transformer) Removes the most recently added instance of the ClassFileTransformer object from the VM's list of registered transformers. After this call completes, the specified ClassFileTransformer object will no longer have its transform() method automatically invoked when class definitions or redefinitions are attempted. param transformer a previously registered ClassFileTransformer. return true if transformer was located in the list of registered transformers and successfully removed. Otherwise, false. throws NullPointerException if transformer is null.