JavaHook – Java Method Hooking Library

A simple, small library for hooking Java methods from C++ without using JVMTI.

⚠️ Correct code execution is guaranteed only on the official Java 8 Update 191 build. For other Java versions, you may need to modify the JDK classes in the JvmStructures.hpp file to match your target version.

Library can:

Intercept method calls
Get arguments of the intercepted method at runtime
Change arguments of the intercepted method at runtime

Examples

Hook for the setFlySpeed method in Minecraft 1.8.8

Hook for the sendChatMessage method in Minecraft 1.8.8

Dependencies

JDK 8 update 191

udis86

Step 1: install JDK and include these folders in your project:

java_folder\jdk1.8.0_191\include
java_folder\jdk1.8.0_191\include\win32
java_folder\jdk1.8.0_191\include\win32\bridge

Also, link the jvm.lib from: java_folder\jdk1.8.0_191\lib.

P.S: Java folder is usually located in C:\Program Files\Java

Step 2: Build udis86 and include it in your project:

Include udis_folder\BuildVS2010\Build\Include

And link libudis86.lib from udis_folder\BuildVS2010\Build\Lib\x64

P.S: Build is usually located in udis_folder\BuildVS2010\Build.

Including the library in a Visual Studio project

Visual Studio 2022 will be used as an example

Clone the repository to a directory you are comfortable with
Open your project in Visual Studio, right-click on the project in the Solution Explorer and select "Properties"
In the "Configuration Properties" section, go to "VC++ Directories", select "Include Directories" and click on the dropdown menu. Click "Edit" and add cloned_repository/include there.
Done!

Requirements