JDA - The Java Disassembler

JDA Logo

Tired of seeing this???

// $FF: Couldn't be decompiled

The Java Disassembler (JDA) is a GUI reverse engineering tool that can turn this:

// $FF: Couldn't be decompiled
// java.lang.IllegalArgumentException: Invalid type: @
//     at org.jetbrains.java.decompiler.struct.gen.VarType.getType(VarType.java:405)
//     at org.jetbrains.java.decompiler.struct.gen.VarType.<init>(VarType.java:90)
//     at org.jetbrains.java.decompiler.struct.gen.VarType.<init>(VarType.java:62)
// ...

into this:

public void keyPressed(KeyEvent var1) {
    int var10000 = var1.getKeyCode();
    int var10001 = (3 << 2 & 9 | 5 | 7) ^ 5;
    int var10003 = 0 ^ 1165448477 ^ 958591453 ^ 2085987521;
    if (var10000 == var10001) {
        11.iiIIiiiiIiIIi(this.IIiiIiiiIIiiI, this.IiIIiiiiiiiiI, this.IIiiiiiiIIiIi);

and finally this:

public void keyPressed(KeyEvent var1) {
    if (var1.getKeyCode() == 10) {
        11.iiIIiiiiIiIIi(this.IIiiIiiiIIiiI, this.IiIIiiiiiiiiI, this.IIiiiiiiIIiIi);


JDA offers powerful static analysis tools, such as control and data flow analysis, and code simplification built using a custom IL. Moreover, many tasks expected of a disassembler such as constant and string searching are available. These standard core utilities are with the MapleIR plugin. You can also access the IL API and integrate into the UI by writing your own plugins in Java. In the near future it will support whole binary cross referencing (xrefs) and more.

MapleIR demo


Due to the growing power and complexity of commercial obfuscation programs for Java, it has become necessary to develop improved reverse engineering and static analysis tools. JDA was developed to provide professional-quality static analysis tools for JVM-based languages.

JDA began as a fork of Bytecode Viewer (BCV). BCV suffered heavily from bloat, poor performance, and stagnant development. In JDA many useless or irrelevant features have been removed, and significant parts of the codebase have been cleaned up or rewritten entirely.


With that in mind, JDA's goal is to be a focused, light-weight yet powerful Java static disassembler. JDA's role is to provide a platform and interface for the core features such as analysis and disassembly. Therefore, JDA's scope is to be a platform for Java reverse engineering tools to be built on top of.

More to come in the future.

MapleIR Plugin

To install the plugin put the plugin jar in ~/.jda/plugins (or equivalently, %USERPROFILE%\.jda\plugins on Windows), then restart.


See COMPILING.md for compilation instructions.