Changing the current working directory in Java?

Question

How can I change the current working directory from within a Java program? Everything I\'ve been able to find about the issue claims that you simply can\'t do it, but I can\

Answer 1

You can change the process's actual working directory using JNI or JNA.

With JNI, you can use native functions to set the directory. The POSIX method is chdir(). On Windows, you can use SetCurrentDirectory().

With JNA, you can wrap the native functions in Java binders.

For Windows:

private static interface MyKernel32 extends Library {
    public MyKernel32 INSTANCE = (MyKernel32) Native.loadLibrary("Kernel32", MyKernel32.class);

    /** BOOL SetCurrentDirectory( LPCTSTR lpPathName ); */
    int SetCurrentDirectoryW(char[] pathName);
}

For POSIX systems:

private interface MyCLibrary extends Library {
    MyCLibrary INSTANCE = (MyCLibrary) Native.loadLibrary("c", MyCLibrary.class);

    /** int chdir(const char *path); */
    int chdir( String path );
}