1: /* Instrumentation.java -- Implementation of this interface is used to 2: instrument Java bytecode. 3: Copyright (C) 2005 Free Software Foundation, Inc. 4: 5: This file is part of GNU Classpath. 6: 7: GNU Classpath is free software; you can redistribute it and/or modify 8: it under the terms of the GNU General Public License as published by 9: the Free Software Foundation; either version 2, or (at your option) 10: any later version. 11: 12: GNU Classpath is distributed in the hope that it will be useful, but 13: WITHOUT ANY WARRANTY; without even the implied warranty of 14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15: General Public License for more details. 16: 17: You should have received a copy of the GNU General Public License 18: along with GNU Classpath; see the file COPYING. If not, write to the 19: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 20: 02110-1301 USA. 21: 22: Linking this library statically or dynamically with other modules is 23: making a combined work based on this library. Thus, the terms and 24: conditions of the GNU General Public License cover the whole 25: combination. 26: 27: As a special exception, the copyright holders of this library give you 28: permission to link this library with independent modules to produce an 29: executable, regardless of the license terms of these independent 30: modules, and to copy and distribute the resulting executable under 31: terms of your choice, provided that you also meet, for each linked 32: independent module, the terms and conditions of the license of that 33: module. An independent module is a module which is not derived from 34: or based on this library. If you modify this library, you may extend 35: this exception to your version of the library, but you are not 36: obligated to do so. If you do not wish to do so, delete this 37: exception statement from your version. */ 38: 39: 40: package java.lang.instrument; 41: 42: /** 43: * An Instrumentation object has transformers that will 44: * be called each time a class is defined or redefined. 45: * The object is given to a <code>premain</code> function 46: * that is called before the <code>main</code> function. 47: * 48: * @author Nicolas Geoffray (nicolas.geoffray@menlina.com) 49: * @since 1.5 50: */ 51: public interface Instrumentation 52: { 53: 54: /** 55: * Adds a <code>ClassFileTransformer</class> object 56: * to the instrumentation. Each time a class is defined 57: * or redefined, the <code>transform</code> method of the 58: * <code>transformer</code> object is called. 59: * 60: * @param transformer the transformer to add 61: * @throws NullPointerException if transformer is null 62: */ 63: void addTransformer(ClassFileTransformer transformer); 64: 65: /** 66: * Removes the given transformer from the set of transformers 67: * this Instrumentation object has. 68: * 69: * @param transformer the transformer to remove 70: * @return true if the transformer was found and removed, false if 71: * the transformer was not found 72: * @throws NullPointerException if transformer is null 73: */ 74: boolean removeTransformer(ClassFileTransformer transformer); 75: 76: /** 77: * Returns if the current JVM supports class redefinition 78: * 79: * @return true if the current JVM supports class redefinition 80: */ 81: boolean isRedefineClassesSupported(); 82: 83: /** 84: * Redefine classes present in the definitions array, with 85: * the corresponding class files. 86: * 87: * @param definitions an array of classes to redefine 88: * 89: * @throws ClassNotFoundException if a class cannot be found 90: * @throws UnmodifiableClassException if a class cannot be modified 91: * @throws UnsupportedOperationException if the JVM does not support 92: * redefinition or the redefinition made unsupported changes 93: * @throws ClassFormatError if a class file is not valid 94: * @throws NoClassDefFoundError if a class name is not equal to the name 95: * in the class file specified 96: * @throws UnsupportedClassVersionError if the class file version numbers 97: * are unsupported 98: * @throws ClassCircularityError if circularity occured with the new 99: * classes 100: * @throws LinkageError if a linkage error occurs 101: * @throws NullPointerException if the definitions array is null, or any 102: * of its element 103: * 104: * @see #isRedefineClassesSupported() 105: * @see #addTransformer(java.lang.instrument.ClassFileTransformer) 106: * @see ClassFileTransformer 107: */ 108: void redefineClasses(ClassDefinition[] definitions) 109: throws ClassNotFoundException, 110: UnmodifiableClassException; 111: 112: 113: /** 114: * Get all the classes loaded by the JVM. 115: * 116: * @return an array containing all the classes loaded by the JVM. The array 117: * is empty if no class is loaded. 118: */ 119: Class[] getAllLoadedClasses(); 120: 121: /** 122: * Get all the classes loaded by a given class loader 123: * 124: * @param loader the loader 125: * 126: * @return an array containing all the classes loaded by the given loader. 127: * The array is empty if no class was loaded by the loader. 128: */ 129: Class[] getInitiatedClasses(ClassLoader loader); 130: 131: /** 132: * Get the size of an object. It contains the size of all fields. 133: * 134: * @param objectToSize the object 135: * @return the size of the object 136: * @throws NullPointerException if objectToSize is null. 137: */ 138: long getObjectSize(Object objectToSize); 139: }