| /* |
| * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.xml.internal.bind.v2.bytecode; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.DataInputStream; |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| |
| import com.sun.xml.internal.bind.Util; |
| |
| /** |
| * Replaces a few constant pool tokens from a class "template" and then loads it into the VM. |
| * |
| * @author Kohsuke Kawaguchi |
| */ |
| public final class ClassTailor { |
| |
| private ClassTailor() {} // no instanciation please |
| |
| private static final Logger logger = Util.getClassLogger(); |
| |
| /** |
| * Returns the class name in the JVM format (such as "java/lang/String") |
| */ |
| public static String toVMClassName( Class c ) { |
| assert !c.isPrimitive(); |
| if(c.isArray()) |
| // I have no idea why it is designed like this, but javap says so. |
| return toVMTypeName(c); |
| return c.getName().replace('.','/'); |
| } |
| |
| public static String toVMTypeName( Class c ) { |
| if(c.isArray()) { |
| // TODO: study how an array type is encoded. |
| return '['+toVMTypeName(c.getComponentType()); |
| } |
| if(c.isPrimitive()) { |
| if(c==Boolean.TYPE) return "Z"; |
| if(c==Character.TYPE) return "C"; |
| if(c==Byte.TYPE) return "B"; |
| if(c==Double.TYPE) return "D"; |
| if(c==Float.TYPE) return "F"; |
| if(c==Integer.TYPE) return "I"; |
| if(c==Long.TYPE) return "J"; |
| if(c==Short.TYPE) return "S"; |
| |
| throw new IllegalArgumentException(c.getName()); |
| } |
| return 'L'+c.getName().replace('.','/')+';'; |
| } |
| |
| |
| |
| public static byte[] tailor( Class templateClass, String newClassName, String... replacements ) { |
| String vmname = toVMClassName(templateClass); |
| return tailor( |
| SecureLoader.getClassClassLoader(templateClass).getResourceAsStream(vmname+".class"), |
| vmname, newClassName, replacements ); |
| } |
| |
| |
| /** |
| * Customizes a class file by replacing constant pools. |
| * |
| * @param image |
| * The image of the template class. |
| * @param replacements |
| * A list of pair of strings that specify the substitution |
| * {@code String[]{search_0, replace_0, search_1, replace_1, ..., search_n, replace_n }} |
| * |
| * The search strings found in the constant pool will be replaced by the corresponding |
| * replacement string. |
| */ |
| public static byte[] tailor( InputStream image, String templateClassName, String newClassName, String... replacements ) { |
| DataInputStream in = new DataInputStream(image); |
| |
| try { |
| ByteArrayOutputStream baos = new ByteArrayOutputStream(1024); |
| DataOutputStream out = new DataOutputStream(baos); |
| |
| // skip until the constant pool count |
| long l = in.readLong(); |
| out.writeLong(l); |
| |
| // read the constant pool size |
| short count = in.readShort(); |
| out.writeShort(count); |
| |
| // replace constant pools |
| for( int i=0; i<count; i++ ) { |
| byte tag = in.readByte(); |
| out.writeByte(tag); |
| switch(tag) { |
| case 0: |
| // this isn't described in the spec, |
| // but class files often seem to have this '0' tag. |
| // we can apparently just ignore it, but not sure |
| // what this really means. |
| break; |
| |
| case 1: // CONSTANT_UTF8 |
| { |
| String value = in.readUTF(); |
| if(value.equals(templateClassName)) |
| value = newClassName; |
| else { |
| for( int j=0; j<replacements.length; j+=2 ) |
| if(value.equals(replacements[j])) { |
| value = replacements[j+1]; |
| break; |
| } |
| } |
| out.writeUTF(value); |
| } |
| break; |
| |
| case 3: // CONSTANT_Integer |
| case 4: // CONSTANT_Float |
| out.writeInt(in.readInt()); |
| break; |
| |
| case 5: // CONSTANT_Long |
| case 6: // CONSTANT_Double |
| i++; // doubles and longs take two entries |
| out.writeLong(in.readLong()); |
| break; |
| |
| case 7: // CONSTANT_Class |
| case 8: // CONSTANT_String |
| out.writeShort(in.readShort()); |
| break; |
| |
| case 9: // CONSTANT_Fieldref |
| case 10: // CONSTANT_Methodref |
| case 11: // CONSTANT_InterfaceMethodref |
| case 12: // CONSTANT_NameAndType |
| out.writeInt(in.readInt()); |
| break; |
| |
| default: |
| throw new IllegalArgumentException("Unknown constant type "+tag); |
| } |
| } |
| |
| // then copy the rest |
| byte[] buf = new byte[512]; |
| int len; |
| while((len=in.read(buf))>0) |
| out.write(buf,0,len); |
| |
| in.close(); |
| out.close(); |
| |
| // by now we got the properly tailored class file image |
| return baos.toByteArray(); |
| |
| } catch( IOException e ) { |
| // never happen |
| logger.log(Level.WARNING,"failed to tailor",e); |
| return null; |
| } |
| } |
| } |