6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 import java.io.*; 26 import java.lang.reflect.*; 27 import java.util.jar.*; 28 29 public class Util { 30 /** 31 * Invoke the loader.defineClass() class method to define the class stored in clsFile, 32 * with the following modification: 33 * <ul> 34 * <li> All ASCII strings in the class file bytes that matches fromString will be replaced with toString. 35 * NOTE: the two strings must be the exact same length. 36 * </ul> 37 */ 38 public static Class defineModifiedClass(ClassLoader loader, File clsFile, String fromString, String toString) 39 throws FileNotFoundException, IOException, NoSuchMethodException, IllegalAccessException, 40 InvocationTargetException 41 { 42 try (DataInputStream dis = new DataInputStream(new FileInputStream(clsFile))) { 43 byte[] buff = new byte[(int)clsFile.length()]; 44 dis.readFully(buff); 45 replace(buff, fromString, toString); 46 47 System.out.println("Loading from: " + clsFile + " (" + buff.length + " bytes)"); 48 49 Method defineClass = ClassLoader.class.getDeclaredMethod("defineClass", 50 buff.getClass(), int.class, int.class); 51 defineClass.setAccessible(true); 52 53 // We directly call into ClassLoader.defineClass() to define the "Super" class. Also, 54 // rewrite its classfile so that it returns ___yyy___ instead of ___xxx___. Changing the 55 // classfile will guarantee that this class will NOT be loaded from the CDS archive. 56 Class cls = (Class)defineClass.invoke(loader, buff, new Integer(0), new Integer(buff.length)); 57 System.out.println("Loaded : " + cls); 58 59 return cls; 60 } 61 } 62 63 /** 64 * @return the number of occurrences of the <code>from</code> string that 65 * have been replaced. 66 */ 67 public static int replace(byte buff[], String from, String to) { 68 if (to.length() != from.length()) { 69 throw new RuntimeException("bad strings"); 70 } 71 byte f[] = asciibytes(from); 72 byte t[] = asciibytes(to); 73 byte f0 = f[0]; 74 75 int numReplaced = 0; 76 int max = buff.length - f.length; 88 public static boolean replace(byte buff[], byte f[], byte t[], int i) { 89 for (int x=0; x<f.length; x++) { 90 if (buff[x+i] != f[x]) { 91 return false; 92 } 93 } 94 for (int x=0; x<f.length; x++) { 95 buff[x+i] = t[x]; 96 } 97 return true; 98 } 99 100 static byte[] asciibytes(String s) { 101 byte b[] = new byte[s.length()]; 102 for (int i=0; i<b.length; i++) { 103 b[i] = (byte)s.charAt(i); 104 } 105 return b; 106 } 107 108 public static Class defineClassFromJAR(ClassLoader loader, File jarFile, String className) 109 throws FileNotFoundException, IOException, NoSuchMethodException, IllegalAccessException, 110 InvocationTargetException { 111 return defineClassFromJAR(loader, jarFile, className, null, null); 112 } 113 114 /** 115 * Invoke the loader.defineClass() class method to define the named class stored in a JAR file. 116 * 117 * If a class exists both in the classpath, as well as in the list of URLs of a URLClassLoader, 118 * by default, the URLClassLoader will not define the class, and instead will delegate to the 119 * app loader. This method is an easy way to force the class to be defined by the URLClassLoader. 120 * 121 * Optionally, you can modify the contents of the classfile buffer. See comments in 122 * defineModifiedClass. 123 */ 124 public static Class defineClassFromJAR(ClassLoader loader, File jarFile, String className, 125 String fromString, String toString) 126 throws FileNotFoundException, IOException, NoSuchMethodException, IllegalAccessException, 127 InvocationTargetException 128 { 129 byte[] buff = getClassFileFromJar(jarFile, className); 130 131 if (fromString != null) { 132 replace(buff, fromString, toString); 133 } 134 135 //System.out.println("Loading from: " + ent + " (" + buff.length + " bytes)"); 136 137 Method defineClass = ClassLoader.class.getDeclaredMethod("defineClass", 138 buff.getClass(), int.class, int.class); 139 defineClass.setAccessible(true); 140 Class cls = (Class)defineClass.invoke(loader, buff, new Integer(0), new Integer(buff.length)); 141 142 //System.out.println("Loaded : " + cls); 143 return cls; 144 } 145 146 public static byte[] getClassFileFromJar(File jarFile, String className) throws FileNotFoundException, IOException { 147 JarFile jf = new JarFile(jarFile); 148 JarEntry ent = jf.getJarEntry(className.replace('.', '/') + ".class"); 149 150 try (DataInputStream dis = new DataInputStream(jf.getInputStream(ent))) { 151 byte[] buff = new byte[(int)ent.getSize()]; 152 dis.readFully(buff); 153 return buff; 154 } 155 } 156 } | 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 import java.io.*; 26 import java.lang.invoke.MethodHandles; 27 import java.lang.invoke.MethodHandles.Lookup; 28 import java.lang.reflect.*; 29 import java.util.jar.*; 30 31 public class Util { 32 /** 33 * Define the class as stored in clsFile, in the same loader as peerClass, 34 * with the following modification: 35 * <ul> 36 * <li> All ASCII strings in the class file bytes that matches fromString will be replaced with toString. 37 * NOTE: the two strings must be the exact same length. 38 * </ul> 39 */ 40 public static Class<?> defineModifiedClass(Class<?> peerClass, File clsFile, String fromString, String toString) 41 throws FileNotFoundException, IOException, NoSuchMethodException, IllegalAccessException, 42 InvocationTargetException 43 { 44 try (DataInputStream dis = new DataInputStream(new FileInputStream(clsFile))) { 45 byte[] buff = new byte[(int)clsFile.length()]; 46 dis.readFully(buff); 47 replace(buff, fromString, toString); 48 49 System.out.println("Loading from: " + clsFile + " (" + buff.length + " bytes)"); 50 51 52 // We directly call into Lookup.defineClass() to define the "Super" class. Also, 53 // rewrite its classfile so that it returns ___yyy___ instead of ___xxx___. Changing the 54 // classfile will guarantee that this class will NOT be loaded from the CDS archive. 55 Lookup lookup = MethodHandles.privateLookupIn(peerClass, MethodHandles.lookup()); 56 Class<?> cls = lookup.defineClass(buff); 57 System.out.println("Loaded : " + cls); 58 59 return cls; 60 } 61 } 62 63 /** 64 * @return the number of occurrences of the <code>from</code> string that 65 * have been replaced. 66 */ 67 public static int replace(byte buff[], String from, String to) { 68 if (to.length() != from.length()) { 69 throw new RuntimeException("bad strings"); 70 } 71 byte f[] = asciibytes(from); 72 byte t[] = asciibytes(to); 73 byte f0 = f[0]; 74 75 int numReplaced = 0; 76 int max = buff.length - f.length; 88 public static boolean replace(byte buff[], byte f[], byte t[], int i) { 89 for (int x=0; x<f.length; x++) { 90 if (buff[x+i] != f[x]) { 91 return false; 92 } 93 } 94 for (int x=0; x<f.length; x++) { 95 buff[x+i] = t[x]; 96 } 97 return true; 98 } 99 100 static byte[] asciibytes(String s) { 101 byte b[] = new byte[s.length()]; 102 for (int i=0; i<b.length; i++) { 103 b[i] = (byte)s.charAt(i); 104 } 105 return b; 106 } 107 108 public static Class defineClassFromJAR(Class<?> peerClass, File jarFile, String className) 109 throws FileNotFoundException, IOException, NoSuchMethodException, IllegalAccessException, 110 InvocationTargetException, ClassNotFoundException { 111 return defineClassFromJAR(peerClass, jarFile, className, null, null); 112 } 113 114 /** 115 * Define the class as stored in clsFile, in the same loader as peerClass. 116 * 117 * If a class exists both in the classpath, as well as in the list of URLs of a URLClassLoader, 118 * by default, the URLClassLoader will not define the class, and instead will delegate to the 119 * app loader. This method is an easy way to force the class to be defined by the URLClassLoader. 120 * 121 * Optionally, you can modify the contents of the classfile buffer. See comments in 122 * defineModifiedClass. 123 */ 124 public static Class<?> defineClassFromJAR(Class<?> peerClass, File jarFile, String className, 125 String fromString, String toString) 126 throws FileNotFoundException, IOException, NoSuchMethodException, IllegalAccessException, 127 InvocationTargetException, ClassNotFoundException 128 { 129 byte[] buff = getClassFileFromJar(jarFile, className); 130 131 if (fromString != null) { 132 replace(buff, fromString, toString); 133 } 134 135 //System.out.println("Loading from: " + ent + " (" + buff.length + " bytes)"); 136 137 Lookup lookup = MethodHandles.privateLookupIn(peerClass, MethodHandles.lookup()); 138 Class<?> cls = lookup.defineClass(buff); 139 140 //System.out.println("Loaded : " + cls); 141 return cls; 142 } 143 144 public static byte[] getClassFileFromJar(File jarFile, String className) throws FileNotFoundException, IOException { 145 JarFile jf = new JarFile(jarFile); 146 JarEntry ent = jf.getJarEntry(className.replace('.', '/') + ".class"); 147 148 try (DataInputStream dis = new DataInputStream(jf.getInputStream(ent))) { 149 byte[] buff = new byte[(int)ent.getSize()]; 150 dis.readFully(buff); 151 return buff; 152 } 153 } 154 155 } |