CODEWITHSUNDEEP
javajava-bytecode-asmbytecode-manipulation
JD9999
JD9999

Reputation: 426

MethodVisitor throwing ClassFormatError

Using ASM, I am replacing the code in a method with another method. The method is called "checkIfShouldDisconnect", and using the BytecodeOutline plugin, I got the ASM code for the source code I wanted to transform. However, I get a ClassFormatError. I believe this is due to my bytecode not being formatted correctly. What have I done wrong?

EDIT 1: The purpose of my code is to edit a external JAR file at runtime. A plugin I am working on, when starts up, will use the attach API to start my agent (separate JAR file). The agent will then get the class and replace the method in the class with another method. In previous debugging, I have printed the bytecode to a swing console through a logger, and I have used ASM's class checker to check the code on the class. It is still active, but it is not giving me anything. The ClassVisitor and MethodVisitor parsed to the RBMethodVisitor is not null

The problem is that the MethodVisitor attempts to insert the code, has no problem but leaves no errors except the ClassFormatError which doesn't tell me the problem with the code.

I'll paste my MethodVisitor here: RBMethodVisitor.java

package RainbowBansTransAgent;

import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

public class RBMethodVisitor extends MethodVisitor implements Opcodes{

    ClassVisitor cv;
    Logger logger;

    public RBMethodVisitor(MethodVisitor mv, ClassVisitor cv) {
        super(Opcodes.ASM5, mv); 
        this.mv = mv;
        this.cv = cv;
        logger = Logger.getLogger(false);
    }

    public void visitCode(){
        logger.logString("overwriting checkIfShouldDisconnect method with new code");
        mv = cv.visitMethod(ACC_PUBLIC, "checkIfShouldDisconnect", "(Ljava/net/SocketAddress;Lcom/mojang/authlib/GameProfile;)Ljava/lang/String;", null, null);
        mv.visitCode();
        Label l0 = new Label();
        Label l1 = new Label();
        Label l2 = new Label();
        mv.visitTryCatchBlock(l0, l1, l2, "java/io/IOException");
        Label l3 = new Label();
        Label l4 = new Label();
        Label l5 = new Label();
        mv.visitTryCatchBlock(l3, l4, l5, "java/io/IOException");
        Label l6 = new Label();
        Label l7 = new Label();
        Label l8 = new Label();
        mv.visitTryCatchBlock(l6, l7, l8, "java/io/IOException");
        Label l9 = new Label();
        mv.visitLabel(l9);
        mv.visitLineNumber(23, l9);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Object", "toString", "()Ljava/lang/String;", false);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Object", "toString", "()Ljava/lang/String;", false);
        mv.visitIntInsn(BIPUSH, 47);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "indexOf", "(I)I", false);
        mv.visitInsn(ICONST_1);
        mv.visitInsn(IADD);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "substring", "(I)Ljava/lang/String;", false);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Object", "toString", "()Ljava/lang/String;", false);
        mv.visitIntInsn(BIPUSH, 58);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "indexOf", "(I)I", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "substring", "(I)Ljava/lang/String;", false);
        mv.visitVarInsn(ASTORE, 3);
        Label l10 = new Label();
        mv.visitLabel(l10);
        mv.visitLineNumber(24, l10);
        mv.visitTypeInsn(NEW, "java/io/File");
        mv.visitInsn(DUP);
        mv.visitLdcInsn("banned-players.json");
        mv.visitMethodInsn(INVOKESPECIAL, "java/io/File", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitVarInsn(ASTORE, 4);
        Label l11 = new Label();
        mv.visitLabel(l11);
        mv.visitLineNumber(25, l11);
        mv.visitTypeInsn(NEW, "joebkt/BannedPlayers");
        mv.visitInsn(DUP);
        mv.visitVarInsn(ALOAD, 4);
        mv.visitMethodInsn(INVOKESPECIAL, "joebkt/BannedPlayers", "<init>", "(Ljava/io/File;)V", false);
        mv.visitVarInsn(ASTORE, 5);
        Label l12 = new Label();
        mv.visitLabel(l12);
        mv.visitLineNumber(26, l12);
        mv.visitTypeInsn(NEW, "java/util/concurrent/ConcurrentHashMap");
        mv.visitInsn(DUP);
        mv.visitMethodInsn(INVOKESPECIAL, "java/util/concurrent/ConcurrentHashMap", "<init>", "()V", false);
        mv.visitVarInsn(ASTORE, 6);
        Label l13 = new Label();
        mv.visitLabel(l13);
        mv.visitLineNumber(28, l13);
        mv.visitFieldInsn(GETSTATIC, "joebkt/_JoeUtils", "DoReconnectDelay", "Z");
        mv.visitJumpInsn(IFEQ, l0);
        Label l14 = new Label();
        mv.visitLabel(l14);
        mv.visitLineNumber(30, l14);
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "com/mojang/authlib/GameProfile", "getName", "()Ljava/lang/String;", false);
        mv.visitVarInsn(ASTORE, 7);
        Label l15 = new Label();
        mv.visitLabel(l15);
        mv.visitLineNumber(31, l15);
        mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J", false);
        mv.visitMethodInsn(INVOKESTATIC, "java/lang/Long", "valueOf", "(J)Ljava/lang/Long;", false);
        mv.visitVarInsn(ASTORE, 8);
        Label l16 = new Label();
        mv.visitLabel(l16);
        mv.visitLineNumber(32, l16);
        mv.visitVarInsn(ALOAD, 6);
        mv.visitVarInsn(ALOAD, 7);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/util/concurrent/ConcurrentHashMap", "get", "(Ljava/lang/Object;)Ljava/lang/Object;", false);
        mv.visitTypeInsn(CHECKCAST, "java/lang/Long");
        mv.visitVarInsn(ASTORE, 9);
        Label l17 = new Label();
        mv.visitLabel(l17);
        mv.visitLineNumber(33, l17);
        mv.visitVarInsn(ALOAD, 9);
        Label l18 = new Label();
        mv.visitJumpInsn(IFNULL, l18);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Long", "longValue", "()J", false);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Long", "longValue", "()J", false);
        mv.visitInsn(LSUB);
        mv.visitFieldInsn(GETSTATIC, "joebkt/_JoeUtils", "ReconnectDelaySeconds", "I");
        mv.visitIntInsn(SIPUSH, 1000);
        mv.visitInsn(IMUL);
        mv.visitInsn(I2L);
        mv.visitInsn(LCMP);
        mv.visitJumpInsn(IFGE, l18);
        Label l19 = new Label();
        mv.visitLabel(l19);
        mv.visitLineNumber(35, l19);
        mv.visitFieldInsn(GETSTATIC, "joebkt/_JoeUtils", "DebugMode", "Z");
        Label l20 = new Label();
        mv.visitJumpInsn(IFEQ, l20);
        Label l21 = new Label();
        mv.visitLabel(l21);
        mv.visitLineNumber(36, l21);
        mv.visitLdcInsn("====== Delaying rejoin for ====== %s -- msDelta: %d ================");
        mv.visitInsn(ICONST_2);
        mv.visitTypeInsn(ANEWARRAY, "java/lang/Object");
        mv.visitInsn(DUP);
        mv.visitInsn(ICONST_0);
        mv.visitVarInsn(ALOAD, 7);
        mv.visitInsn(AASTORE);
        mv.visitInsn(DUP);
        mv.visitInsn(ICONST_1);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Long", "longValue", "()J", false);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Long", "longValue", "()J", false);
        mv.visitInsn(LSUB);
        mv.visitMethodInsn(INVOKESTATIC, "java/lang/Long", "valueOf", "(J)Ljava/lang/Long;", false);
        mv.visitInsn(AASTORE);
        mv.visitMethodInsn(INVOKESTATIC, "java/lang/String", "format", "(Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKESTATIC, "joebkt/_JoeUtils", "ConsoleMsg", "(Ljava/lang/String;)V", false);
        mv.visitLabel(l20);
        mv.visitLineNumber(38, l20);
        mv.visitFrame(Opcodes.F_FULL, 10, new Object[] {"Testers/ClassToVisit", "java/net/SocketAddress", "com/mojang/authlib/GameProfile", "java/lang/String", "java/io/File", "joebkt/BannedPlayers", "java/util/concurrent/ConcurrentHashMap", "java/lang/String", "java/lang/Long", "java/lang/Long"}, 0, new Object[] {});
        mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
        mv.visitInsn(DUP);
        mv.visitLdcInsn("There is a ");
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitFieldInsn(GETSTATIC, "joebkt/_JoeUtils", "ReconnectDelaySeconds", "I");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;", false);
        mv.visitLdcInsn("-second reconnect delay.");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
        mv.visitInsn(ARETURN);
        mv.visitLabel(l18);
        mv.visitLineNumber(40, l18);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitVarInsn(ALOAD, 6);
        mv.visitVarInsn(ALOAD, 7);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/util/concurrent/ConcurrentHashMap", "put", "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;", false);
        mv.visitInsn(POP);
        mv.visitLabel(l0);
        mv.visitLineNumber(43, l0);
        mv.visitFrame(Opcodes.F_CHOP,3, null, 0, null);
        mv.visitVarInsn(ALOAD, 5);
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/BannedPlayers", "a", "(Lcom/mojang/authlib/GameProfile;)Z", false);
        Label l22 = new Label();
        mv.visitJumpInsn(IFEQ, l22);
        Label l23 = new Label();
        mv.visitLabel(l23);
        mv.visitLineNumber(45, l23);
        mv.visitVarInsn(ALOAD, 5);
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/BannedPlayers", "b", "(Ljava/lang/Object;)Ljoebkt/sr;", false);
        mv.visitTypeInsn(CHECKCAST, "joebkt/sw_BanByNameUUID");
        mv.visitVarInsn(ASTORE, 7);
        Label l24 = new Label();
        mv.visitLabel(l24);
        mv.visitLineNumber(46, l24);
        mv.visitTypeInsn(NEW, "java/io/File");
        mv.visitInsn(DUP);
        mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
        mv.visitInsn(DUP);
        mv.visitLdcInsn("plugins_mod");
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitFieldInsn(GETSTATIC, "java/io/File", "separator", "Ljava/lang/String;");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitLdcInsn("RainbowBans");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitFieldInsn(GETSTATIC, "java/io/File", "separator", "Ljava/lang/String;");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitLdcInsn("banmessage.txt");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKESPECIAL, "java/io/File", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitVarInsn(ASTORE, 8);
        Label l25 = new Label();
        mv.visitLabel(l25);
        mv.visitLineNumber(47, l25);
        mv.visitTypeInsn(NEW, "java/io/BufferedReader");
        mv.visitInsn(DUP);
        mv.visitTypeInsn(NEW, "java/io/FileReader");
        mv.visitInsn(DUP);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitMethodInsn(INVOKESPECIAL, "java/io/FileReader", "<init>", "(Ljava/io/File;)V", false);
        mv.visitMethodInsn(INVOKESPECIAL, "java/io/BufferedReader", "<init>", "(Ljava/io/Reader;)V", false);
        mv.visitVarInsn(ASTORE, 9);
        Label l26 = new Label();
        mv.visitLabel(l26);
        mv.visitLineNumber(48, l26);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/BufferedReader", "readLine", "()Ljava/lang/String;", false);
        mv.visitVarInsn(ASTORE, 10);
        Label l27 = new Label();
        mv.visitLabel(l27);
        mv.visitLineNumber(49, l27);
        mv.visitVarInsn(ALOAD, 10);
        mv.visitLdcInsn("%PLAYER%");
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "com/mojang/authlib/GameProfile", "getName", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "replaceAll", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;", false);
        mv.visitLdcInsn("%REASON%");
        mv.visitVarInsn(ALOAD, 7);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/sw_BanByNameUUID", "d", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "replaceAll", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;", false);
        mv.visitLdcInsn("%CURRENTTIME%");
        mv.visitTypeInsn(NEW, "java/util/Date");
        mv.visitInsn(DUP);
        mv.visitMethodInsn(INVOKESPECIAL, "java/util/Date", "<init>", "()V", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/util/Date", "toString", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "replaceAll", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;", false);
        mv.visitVarInsn(ASTORE, 11);
        Label l28 = new Label();
        mv.visitLabel(l28);
        mv.visitLineNumber(50, l28);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/BufferedReader", "close", "()V", false);
        Label l29 = new Label();
        mv.visitLabel(l29);
        mv.visitLineNumber(51, l29);
        mv.visitVarInsn(ALOAD, 11);
        mv.visitLabel(l1);
        mv.visitInsn(ARETURN);
        mv.visitLabel(l2);
        mv.visitLineNumber(53, l2);
        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] {"java/io/IOException"});
        mv.visitVarInsn(ASTORE, 7);
        Label l30 = new Label();
        mv.visitLabel(l30);
        mv.visitLineNumber(54, l30);
        mv.visitVarInsn(ALOAD, 7);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/IOException", "printStackTrace", "()V", false);
        mv.visitLabel(l22);
        mv.visitLineNumber(63, l22);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitMethodInsn(INVOKESTATIC, "net/minecraft/server/MinecraftServer", "getServer", "()Lnet/minecraft/server/MinecraftServer;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "net/minecraft/server/MinecraftServer", "getThePlayerList", "()Ljoebkt/PlayerList;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/PlayerList", "getWhitelist", "()Z", false);
        mv.visitVarInsn(ISTORE, 7);
        Label l31 = new Label();
        mv.visitLabel(l31);
        mv.visitLineNumber(69, l31);
        mv.visitVarInsn(ILOAD, 7);
        Label l32 = new Label();
        mv.visitJumpInsn(IFEQ, l32);
        Label l33 = new Label();
        mv.visitLabel(l33);
        mv.visitLineNumber(70, l33);
        mv.visitInsn(ACONST_NULL);
        mv.visitVarInsn(ASTORE, 8);
        mv.visitLabel(l3);
        mv.visitLineNumber(72, l3);
        mv.visitTypeInsn(NEW, "java/lang/String");
        mv.visitInsn(DUP);
        mv.visitFieldInsn(GETSTATIC, "joebkt/PlayerList", "fileWhitelist", "Ljava/io/File;");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/File", "toURI", "()Ljava/net/URI;", false);
        mv.visitMethodInsn(INVOKESTATIC, "java/nio/file/Paths", "get", "(Ljava/net/URI;)Ljava/nio/file/Path;", false);
        mv.visitMethodInsn(INVOKESTATIC, "java/nio/file/Files", "readAllBytes", "(Ljava/nio/file/Path;)[B", false);
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/String", "<init>", "([B)V", false);
        mv.visitVarInsn(ASTORE, 8);
        mv.visitLabel(l4);
        mv.visitLineNumber(73, l4);
        Label l34 = new Label();
        mv.visitJumpInsn(GOTO, l34);
        mv.visitLabel(l5);
        mv.visitFrame(Opcodes.F_FULL, 9, new Object[] {"Testers/ClassToVisit", "java/net/SocketAddress", "com/mojang/authlib/GameProfile", "java/lang/String", "java/io/File", "joebkt/BannedPlayers", "java/util/concurrent/ConcurrentHashMap", Opcodes.INTEGER, "java/lang/String"}, 1, new Object[] {"java/io/IOException"});
        mv.visitVarInsn(ASTORE, 9);
        Label l35 = new Label();
        mv.visitLabel(l35);
        mv.visitLineNumber(74, l35);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/IOException", "printStackTrace", "()V", false);
        mv.visitLabel(l34);
        mv.visitLineNumber(76, l34);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitLdcInsn("[]");
        mv.visitJumpInsn(IF_ACMPEQ, l32);
        Label l36 = new Label();
        mv.visitLabel(l36);
        mv.visitLineNumber(78, l36);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "com/mojang/authlib/GameProfile", "getName", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "contains", "(Ljava/lang/CharSequence;)Z", false);
        mv.visitJumpInsn(IFNE, l32);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitVarInsn(ALOAD, 3);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "contains", "(Ljava/lang/CharSequence;)Z", false);
        mv.visitJumpInsn(IFNE, l32);
        Label l37 = new Label();
        mv.visitLabel(l37);
        mv.visitLineNumber(79, l37);
        mv.visitLdcInsn("You are not whitelisted on this server!");
        mv.visitInsn(ARETURN);
        mv.visitLabel(l32);
        mv.visitLineNumber(83, l32);
        mv.visitFrame(Opcodes.F_CHOP,1, null, 0, null);
        mv.visitTypeInsn(NEW, "joebkt/BannedIPs");
        mv.visitInsn(DUP);
        mv.visitFieldInsn(GETSTATIC, "joebkt/PlayerList", "fileBannedIPs", "Ljava/io/File;");
        mv.visitMethodInsn(INVOKESPECIAL, "joebkt/BannedIPs", "<init>", "(Ljava/io/File;)V", false);
        mv.visitVarInsn(ASTORE, 8);
        Label l38 = new Label();
        mv.visitLabel(l38);
        mv.visitLineNumber(84, l38);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/BannedIPs", "a", "(Ljava/net/SocketAddress;)Z", false);
        Label l39 = new Label();
        mv.visitJumpInsn(IFEQ, l39);
        Label l40 = new Label();
        mv.visitLabel(l40);
        mv.visitLineNumber(85, l40);
        mv.visitTypeInsn(NEW, "java/io/File");
        mv.visitInsn(DUP);
        mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
        mv.visitInsn(DUP);
        mv.visitLdcInsn("plugins_mod");
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitFieldInsn(GETSTATIC, "java/io/File", "separator", "Ljava/lang/String;");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitLdcInsn("RainbowBans");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitFieldInsn(GETSTATIC, "java/io/File", "separator", "Ljava/lang/String;");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitLdcInsn("banmessage.txt");
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKESPECIAL, "java/io/File", "<init>", "(Ljava/lang/String;)V", false);
        mv.visitVarInsn(ASTORE, 9);
        mv.visitLabel(l6);
        mv.visitLineNumber(87, l6);
        mv.visitVarInsn(ALOAD, 8);
        mv.visitVarInsn(ALOAD, 1);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/BannedIPs", "b", "(Ljava/net/SocketAddress;)Ljoebkt/se_BanByIP;", false);
        mv.visitVarInsn(ASTORE, 10);
        Label l41 = new Label();
        mv.visitLabel(l41);
        mv.visitLineNumber(88, l41);
        mv.visitTypeInsn(NEW, "java/io/BufferedReader");
        mv.visitInsn(DUP);
        mv.visitTypeInsn(NEW, "java/io/FileReader");
        mv.visitInsn(DUP);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKESPECIAL, "java/io/FileReader", "<init>", "(Ljava/io/File;)V", false);
        mv.visitMethodInsn(INVOKESPECIAL, "java/io/BufferedReader", "<init>", "(Ljava/io/Reader;)V", false);
        mv.visitVarInsn(ASTORE, 11);
        Label l42 = new Label();
        mv.visitLabel(l42);
        mv.visitLineNumber(89, l42);
        mv.visitVarInsn(ALOAD, 11);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/BufferedReader", "readLine", "()Ljava/lang/String;", false);
        mv.visitVarInsn(ASTORE, 12);
        Label l43 = new Label();
        mv.visitLabel(l43);
        mv.visitLineNumber(90, l43);
        mv.visitVarInsn(ALOAD, 12);
        mv.visitLdcInsn("%PLAYER%");
        mv.visitVarInsn(ALOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "com/mojang/authlib/GameProfile", "getName", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "replaceAll", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;", false);
        mv.visitLdcInsn("%REASON%");
        mv.visitVarInsn(ALOAD, 10);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/se_BanByIP", "d", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "replaceAll", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;", false);
        mv.visitLdcInsn("%CURRENTTIME%");
        mv.visitTypeInsn(NEW, "java/util/Date");
        mv.visitInsn(DUP);
        mv.visitMethodInsn(INVOKESPECIAL, "java/util/Date", "<init>", "()V", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/util/Date", "toString", "()Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "replaceAll", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;", false);
        mv.visitVarInsn(ASTORE, 13);
        Label l44 = new Label();
        mv.visitLabel(l44);
        mv.visitLineNumber(91, l44);
        mv.visitVarInsn(ALOAD, 11);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/BufferedReader", "close", "()V", false);
        Label l45 = new Label();
        mv.visitLabel(l45);
        mv.visitLineNumber(92, l45);
        mv.visitVarInsn(ALOAD, 13);
        mv.visitLabel(l7);
        mv.visitInsn(ARETURN);
        mv.visitLabel(l8);
        mv.visitLineNumber(93, l8);
        mv.visitFrame(Opcodes.F_FULL, 10, new Object[] {"Testers/ClassToVisit", "java/net/SocketAddress", "com/mojang/authlib/GameProfile", "java/lang/String", "java/io/File", "joebkt/BannedPlayers", "java/util/concurrent/ConcurrentHashMap", Opcodes.INTEGER, "joebkt/BannedIPs", "java/io/File"}, 1, new Object[] {"java/io/IOException"});
        mv.visitVarInsn(ASTORE, 10);
        Label l46 = new Label();
        mv.visitLabel(l46);
        mv.visitLineNumber(94, l46);
        mv.visitVarInsn(ALOAD, 10);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/IOException", "printStackTrace", "()V", false);
        mv.visitLabel(l39);
        mv.visitLineNumber(107, l39);
        mv.visitFrame(Opcodes.F_CHOP,1, null, 0, null);
        mv.visitMethodInsn(INVOKESTATIC, "net/minecraft/server/MinecraftServer", "getServer", "()Lnet/minecraft/server/MinecraftServer;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "net/minecraft/server/MinecraftServer", "getThePlayerList", "()Ljoebkt/PlayerList;", false);
        mv.visitVarInsn(ASTORE, 9);
        Label l47 = new Label();
        mv.visitLabel(l47);
        mv.visitLineNumber(108, l47);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/PlayerList", "getNumPlayers", "()I", false);
        mv.visitVarInsn(ALOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "joebkt/PlayerList", "getMaxPlayers", "()I", false);
        Label l48 = new Label();
        mv.visitJumpInsn(IF_ICMPLT, l48);
        mv.visitLdcInsn("The server is full!");
        Label l49 = new Label();
        mv.visitJumpInsn(GOTO, l49);
        mv.visitLabel(l48);
        mv.visitFrame(Opcodes.F_APPEND,1, new Object[] {"joebkt/PlayerList"}, 0, null);
        mv.visitInsn(ACONST_NULL);
        mv.visitLabel(l49);
        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] {"java/lang/String"});
        mv.visitInsn(ARETURN);
        Label l50 = new Label();
        mv.visitLabel(l50);
        mv.visitLocalVariable("this", "LTesters/ClassToVisit;", null, l9, l50, 0);
        mv.visitLocalVariable("addr", "Ljava/net/SocketAddress;", null, l9, l50, 1);
        mv.visitLocalVariable("profile", "Lcom/mojang/authlib/GameProfile;", null, l9, l50, 2);
        mv.visitLocalVariable("ip", "Ljava/lang/String;", null, l10, l50, 3);
        mv.visitLocalVariable("fileBannedPlayers", "Ljava/io/File;", null, l11, l50, 4);
        mv.visitLocalVariable("bp", "Ljoebkt/BannedPlayers;", null, l12, l50, 5);
        mv.visitLocalVariable("lastConnectTime", "Ljava/util/concurrent/ConcurrentHashMap;", "Ljava/util/concurrent/ConcurrentHashMap<Ljava/lang/String;Ljava/lang/Long;>;", l13, l50, 6);
        mv.visitLocalVariable("pName", "Ljava/lang/String;", null, l15, l0, 7);
        mv.visitLocalVariable("msNow", "Ljava/lang/Long;", null, l16, l0, 8);
        mv.visitLocalVariable("msLast", "Ljava/lang/Long;", null, l17, l0, 9);
        mv.visitLocalVariable("var5", "Ljoebkt/sw_BanByNameUUID;", null, l24, l2, 7);
        mv.visitLocalVariable("file", "Ljava/io/File;", null, l25, l2, 8);
        mv.visitLocalVariable("reader", "Ljava/io/BufferedReader;", null, l26, l2, 9);
       mv.visitLocalVariable("reason", "Ljava/lang/String;", null, l27, l2, 10);
        mv.visitLocalVariable("rep", "Ljava/lang/String;", null, l28, l2, 11);
        mv.visitLocalVariable("e", "Ljava/io/IOException;", null, l30, l22, 7);
        mv.visitLocalVariable("whitelist", "Z", null, l31, l50, 7);
        mv.visitLocalVariable("whitelisters", "Ljava/lang/String;", null, l3, l32, 8);
        mv.visitLocalVariable("e", "Ljava/io/IOException;", null, l35, l34, 9);
        mv.visitLocalVariable("bi", "Ljoebkt/BannedIPs;", null, l38, l50, 8);
        mv.visitLocalVariable("file", "Ljava/io/File;", null, l6, l39, 9);
        mv.visitLocalVariable("var3", "Ljoebkt/se_BanByIP;", null, l41, l8, 10);
        mv.visitLocalVariable("reader", "Ljava/io/BufferedReader;", null, l42, l8, 11);
        mv.visitLocalVariable("line", "Ljava/lang/String;", null, l43, l8, 12);
        mv.visitLocalVariable("rep", "Ljava/lang/String;", null, l44, l8, 13);
        mv.visitLocalVariable("e", "Ljava/io/IOException;", null, l46, l39, 10);
        mv.visitLocalVariable("ls", "Ljoebkt/PlayerList;", null, l47, l50, 9);
        mv.visitMaxs(8, 14);
        mv.visitEnd();
    }

}

EDIT 2: Here is my class visitor:

package RainbowBansTransAgent;

import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

public class RBClassVisitor extends ClassVisitor{

    public RBClassVisitor(ClassVisitor c) {
        super(Opcodes.ASM5, c);
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc,
        String signature, String[] exceptions) {
        if(name.equals("checkIfShouldDisconnect")){
            Logger.getLogger(false).logString("Found method to replace!");
            RBMethodVisitor vs = new RBMethodVisitor(cv.visitMethod(access, name, desc, signature, exceptions), cv);
            vs.visitCode();
            return null;
        }else return cv.visitMethod(access, name, desc, signature, exceptions); 
    }

}

Upvotes: 1

Views: 434

Answers (1)

JD9999
JD9999

Reputation: 426

I fixed this by commenting out the visitMaxs() call. I also moved all the code from the visitCode() method of the RBMethodVisitor into the RBClassVisitor's visitMethod() method.

Upvotes: 1

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