declare namespace java { namespace lang { namespace instrument { /** * An agent provides an implementation of this interface in order * to transform class files. * The transformation occurs before the class is defined by the JVM. *

* Note the term class file is used as defined in section 3.1 of * The Java™ Virtual Machine Specification, * to mean a sequence * of bytes in class file format, whether or not they reside in a file. * @see java.lang.instrument.Instrumentation * @see java.lang.instrument.Instrumentation#addTransformer * @see java.lang.instrument.Instrumentation#removeTransformer * @since 1.5 */ // @ts-ignore interface ClassFileTransformer { /** * The implementation of this method may transform the supplied class file and * return a new replacement class file. *

* There are two kinds of transformers, determined by the canRetransform * parameter of * {@link java.lang.instrument.Instrumentation#addTransformer(ClassFileTransformer,boolean)}: *

*

* Once a transformer has been registered with * {@link java.lang.instrument.Instrumentation#addTransformer(ClassFileTransformer,boolean) * addTransformer}, * the transformer will be called for every new class definition and every class redefinition. * Retransformation capable transformers will also be called on every class retransformation. * The request for a new class definition is made with * {@link java.lang.ClassLoader#defineClass ClassLoader.defineClass} * or its native equivalents. * The request for a class redefinition is made with * {@link java.lang.instrument.Instrumentation#redefineClasses Instrumentation.redefineClasses} * or its native equivalents. * The request for a class retransformation is made with * {@link java.lang.instrument.Instrumentation#retransformClasses Instrumentation.retransformClasses} * or its native equivalents. * The transformer is called during the processing of the request, before the class file bytes * have been verified or applied. * When there are multiple transformers, transformations are composed by chaining the * transform calls. * That is, the byte array returned by one call to transform becomes the input * (via the classfileBuffer parameter) to the next call. *

* Transformations are applied in the following order: *

*

* For retransformations, the retransformation incapable transformers are not * called, instead the result of the previous transformation is reused. * In all other cases, this method is called. * Within each of these groupings, transformers are called in the order registered. * Native transformers are provided by the ClassFileLoadHook event * in the Java Virtual Machine Tool Interface). *

* The input (via the classfileBuffer parameter) to the first * transformer is: *

*

* If the implementing method determines that no transformations are needed, * it should return null. * Otherwise, it should create a new byte[] array, * copy the input classfileBuffer into it, * along with all desired transformations, and return the new array. * The input classfileBuffer must not be modified. *

* In the retransform and redefine cases, * the transformer must support the redefinition semantics: * if a class that the transformer changed during initial definition is later * retransformed or redefined, the * transformer must insure that the second class output class file is a legal * redefinition of the first output class file. *

* If the transformer throws an exception (which it doesn't catch), * subsequent transformers will still be called and the load, redefine * or retransform will still be attempted. * Thus, throwing an exception has the same effect as returning null. * To prevent unexpected behavior when unchecked exceptions are generated * in transformer code, a transformer can catch Throwable. * If the transformer believes the classFileBuffer does not * represent a validly formatted class file, it should throw * an IllegalClassFormatException; * while this has the same effect as returning null. it facilitates the * logging or debugging of format corruptions. * @param loader the defining loader of the class to be transformed, * may be null if the bootstrap loader * @param className 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". * @param classBeingRedefined if this is triggered by a redefine or retransform, * the class being redefined or retransformed; * if this is a class load, null * @param protectionDomain the protection domain of the class being defined or redefined * @param classfileBuffer the input byte buffer in class file format - must not be modified * @throws IllegalClassFormatException if the input does not represent a well-formed class file * @return a well-formed class file buffer (the result of the transform), * or null if no transform is performed. * @see Instrumentation#redefineClasses */ // @ts-ignore transform(loader: java.lang.ClassLoader, className: java.lang.String | string, classBeingRedefined: java.lang.Class, protectionDomain: java.security.ProtectionDomain, classfileBuffer: number /*byte*/[]): number /*byte*/[] } } } }