import java.io.*; class InstallSDE { static final boolean verbose = true; static final String nameSDE = "SourceDebugExtension"; byte[] orig; byte[] sdeAttr; byte[] gen; int origPos = 0; int genPos = 0; int sdeIndex; public static void main(String[] args) throws IOException { if (args.length == 2) { install(new File(args[0]), new File(args[1])); } else if (args.length == 3) { install(new File(args[0]), new File(args[1]), new File(args[2])); } else { abort("Usage: " + " \n" + " "); } } static void install(File inClassFile, File attrFile, File outClassFile) throws IOException { new InstallSDE(inClassFile, attrFile, outClassFile); } static void install(File inOutClassFile, File attrFile) throws IOException { File tmpFile = new File(inOutClassFile.getPath() + "tmp"); new InstallSDE(inOutClassFile, attrFile, tmpFile); if (!inOutClassFile.delete()) { throw new IOException("inOutClassFile.delete() failed"); } if (!tmpFile.renameTo(inOutClassFile)) { throw new IOException("tmpFile.renameTo(inOutClassFile) failed"); } } static void abort(String msg) { System.err.println(msg); System.exit(1); } InstallSDE(File inClassFile, File attrFile, File outClassFile) throws IOException { if (!inClassFile.exists()) { abort("no such file: " + inClassFile); } if (!attrFile.exists()) { abort("no such file: " + attrFile); } // get the bytes orig = readWhole(inClassFile); sdeAttr = readWhole(attrFile); gen = new byte[orig.length + sdeAttr.length + 100]; // do it addSDE(); // write result FileOutputStream outStream = new FileOutputStream(outClassFile); outStream.write(gen, 0, genPos); outStream.close(); } byte[] readWhole(File input) throws IOException { FileInputStream inStream = new FileInputStream(input); int len = (int)input.length(); byte[] bytes = new byte[len]; if (inStream.read(bytes, 0, len) != len) { abort("expected size: " + len); } inStream.close(); return bytes; } void addSDE() throws UnsupportedEncodingException { int i; copy(4 + 2 + 2); // magic min/maj version int constantPoolCountPos = genPos; int constantPoolCount = readU2(); writeU2(constantPoolCount); // copy old constant pool return index of SDE symbol, if found sdeIndex = copyConstantPool(constantPoolCount); if (sdeIndex < 0) { // if "SourceDebugExtension" symbol not there add it writeUtf8ForSDE(); // increment the countantPoolCount sdeIndex = constantPoolCount; ++constantPoolCount; randomAccessWriteU2(constantPoolCountPos, constantPoolCount); if (verbose) { System.out.println("SourceDebugExtension not found, installed at: " + sdeIndex); } } else { if (verbose) { System.out.println("SourceDebugExtension found at: " + sdeIndex); } } copy(2 + 2 + 2); // access, this, super int interfaceCount = readU2(); writeU2(interfaceCount); if (verbose) { System.out.println("interfaceCount: " + interfaceCount); } copy(interfaceCount * 2); copyMembers(); // fields copyMembers(); // methods int attrCountPos = genPos; int attrCount = readU2(); writeU2(attrCount); if (verbose) { System.out.println("class attrCount: " + attrCount); } // copy the class attributes, return true if SDE attr found (not copied) if (!copyAttrs(attrCount)) { // we will be adding SDE and it isn't already counted ++attrCount; randomAccessWriteU2(attrCountPos, attrCount); if (verbose) { System.out.println("class attrCount incremented"); } } writeAttrForSDE(sdeIndex); } void copyMembers() { int count = readU2(); writeU2(count); if (verbose) { System.out.println("members count: " + count); } for (int i = 0; i < count; ++i) { copy(6); // access, name, descriptor int attrCount = readU2(); writeU2(attrCount); if (verbose) { System.out.println("member attr count: " + attrCount); } copyAttrs(attrCount); } } boolean copyAttrs(int attrCount) { boolean sdeFound = false; for (int i = 0; i < attrCount; ++i) { int nameIndex = readU2(); // don't write old SDE if (nameIndex == sdeIndex) { sdeFound = true; if (verbose) { System.out.println("SDE attr found"); } } else { writeU2(nameIndex); // name int len = readU4(); writeU4(len); copy(len); if (verbose) { System.out.println("attr len: " + len); } } } return sdeFound; } void writeAttrForSDE(int index) { writeU2(index); writeU4(sdeAttr.length); for (int i = 0; i < sdeAttr.length; ++i) { writeU1(sdeAttr[i]); } } void randomAccessWriteU2(int pos, int val) { int savePos = genPos; genPos = pos; writeU2(val); genPos = savePos; } int readU1() { return ((int)orig[origPos++]) & 0xFF; } int readU2() { int res = readU1(); return (res << 8) + readU1(); } int readU4() { int res = readU2(); return (res << 16) + readU2(); } void writeU1(int val) { gen[genPos++] = (byte)val; } void writeU2(int val) { writeU1(val >> 8); writeU1(val & 0xFF); } void writeU4(int val) { writeU2(val >> 16); writeU2(val & 0xFFFF); } void copy(int count) { for (int i = 0; i < count; ++i) { gen[genPos++] = orig[origPos++]; } } byte[] readBytes(int count) { byte[] bytes = new byte[count]; for (int i = 0; i < count; ++i) { bytes[i] = orig[origPos++]; } return bytes; } void writeBytes(byte[] bytes) { for (int i = 0; i < bytes.length; ++i) { gen[genPos++] = bytes[i]; } } int copyConstantPool(int constantPoolCount) throws UnsupportedEncodingException { int sdeIndex = -1; // copy const pool index zero not in class file for (int i = 1; i < constantPoolCount; ++i) { int tag = readU1(); writeU1(tag); switch (tag) { case 7: // Class case 8: // String copy(2); break; case 9: // Field case 10: // Method case 11: // InterfaceMethod case 3: // Integer case 4: // Float case 12: // NameAndType copy(4); break; case 5: // Long case 6: // Double copy(8); break; case 1: // Utf8 int len = readU2(); writeU2(len); byte[] utf8 = readBytes(len); String str = new String(utf8, "UTF-8"); if (verbose) { System.out.println(i + " read class attr -- '" + str + "'"); } if (str.equals(nameSDE)) { sdeIndex = i; } writeBytes(utf8); break; default: abort("unexpected tag: " + tag); break; } } return sdeIndex; } void writeUtf8ForSDE() { int len = nameSDE.length(); writeU1(1); // Utf8 tag writeU2(len); for (int i = 0; i < len; ++i) { writeU1(nameSDE.charAt(i)); } } }