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javabytecodebytecode-manipulationbcel

How to change value of a static field using BCEL?

I want to reset a static field using BCEL, for instance 

private static final int myValue = 1;

to myValue = 2. Using another bytecode library such as ASM is not possible.

Solution

  • The code in my question: Injecting code in an existing method using BCEL used to edit a static array. I however later changed it to edit a local variable. The code to edit a static variable was something like this:

    InstructionList il = new InstructionList();
InstructionFactory f = new InstructionFactory(constantPoolGen);
il.append(f.createGetStatic("MyClassName","MyVariableName",Type.INT));
il.append(new PUSH(contantPoolGen, 2));
il.append(new ISTORE());

    The InstructionList I used got injected in a method so i'm not sure if that works for you..