Unsafe utility class

T.java

import java.lang.reflect.Field;
import sun.misc.Unsafe;

public class T {

    public static Unsafe u;
    private static long fieldOffset;
    private static T instance = new T();
    private Object obj;

    static {
        try {
            Field f = Unsafe.class.getDeclaredField("theUnsafe");
            f.setAccessible(true);

            u = (Unsafe) f.get(null);
            fieldOffset = u.objectFieldOffset(T.class.getDeclaredField("obj"));
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    };

    public synchronized static long o2a(Object o) {
        instance.obj = o;
        return u.getLong(instance, fieldOffset);
    }

    public synchronized static Object a2o(long address) {
        u.putLong(instance, fieldOffset, address);
        return instance.obj;
    }

    public static Unsafe get() {
        return u;
    }
}