Endianness of Java

In Java, multibyte data items or streams are stored in big endian order.

Using Java to write bytes directly to the wire will require byte-order transformation if the recipient talks in little endian. The same is true if you are reading directly from the wire from a sender who talks in little endian.

If you are using a byte array wrapped in ByteBuffer,

byte[] data = new byte[] { 12, 19, 83, 05, -05,  55, -55 };
ByteBuffer byteBuffer = ByteBuffer.wrap(data);

Transforming from big endian to little endian is easy,

byteBuffer.order(java.nio.ByteOrder.LITTLE_ENDIAN);

If you are unsure of the endianness of the underlying platform, just invoke the native order method.

java.nio.ByteOrder.nativeOrder();

Aside from streams, operands in classes that are above 1 byte in size are in big endian order.