Java相当于ntohll函数

Question

Is there an equivalent of ntohll C++ function in Java?

The reference of ntohll can be found here: ntohll function .

The thing is I need to convert a 64 bits long from TCP/IP network order to little endian long.

Answer 1

java equivalent function of ntohll is: long is equivalent of 64 bit

    import java.nio.ByteBuffer;
    import java.nio.ByteOrder;

   public long ntohll(long convert)
    {
            ByteBuffer bbuf = ByteBuffer.allocate(8);  
            bbuf.order(ByteOrder.BIG_ENDIAN);  
            bbuf.putLong(convert);  
            bbuf.order(ByteOrder.LITTLE_ENDIAN);  
            return bbuf.getLong(0); 
    }

Answer 2

Java uses network byte order already, so there is no need to convert them (which is why these functions do not exist in Java).

Update

Since you are reading a file that is in little endian bit patterns, you have to write your own (or use a library) if you are using JDK < 1.5. If you are using JDK 1.5 or higher, you can use the reverseBytes method for the integer objects:

long data = Long.reverseBytes(some_data);