通过偏移量在 Java/JNA 中调用函数

import com.sun.jna.Function;
import com.sun.jna.Native;
import com.sun.jna.Pointer;
import com.sun.jna.Library;

public class CallFunctionByOffset {

    public interface CLibrary extends Library {
        CLibrary INSTANCE = (CLibrary) Native.load("aaa", CLibrary.class);

        // 声明已知的函数，例如 obj1
        void obj1();
    }

    public static void main(String[] args) {
        String libraryName = "aaa"; // 动态链接库的名称
        String functionName = "obj1"; // 已知函数的名称
        long offset = 0xFF; // 目标函数相对于已知函数的偏移量

        // 1. 获取已知函数的 Function 对象
        Function obj1 = Function.getFunction(libraryName, functionName);

        // 2. 获取已知函数的指针地址
        Pointer obj1Pointer = obj1.getPointer();
        long obj1Address = Pointer.nativeValue(obj1Pointer);

        // 3. 计算目标函数的地址
        long obj2Address = obj1Address + offset;

        // 4. 创建目标函数的 Function 对象
        Function obj2 = Function.getFunction(new Pointer(obj2Address), "void", new Class<?>[]{});

        // 5. 调用目标函数
        if (obj2 != null) {
            obj2.invoke(void.class, new Object[]{});
            System.out.println("Successfully called obj2 at address: 0x" + Long.toHexString(obj2Address));
        } else {
            System.err.println("Failed to get function obj2 at address: 0x" + Long.toHexString(obj2Address));
        }
    }
}