java整型数与网络字节序的byte[] 数组转换关系工作项目需要在java和c/c++之间进行socket通信，socket通信是以字节流或者字节包进行的，socket发送方须将数据转换为字节流或者字节包，而接收方则将字节流和字节包再转换回相应的数据类型。

如果发送方和接收方都是同种语言，则一般只涉及到字节序的调整。

而对于java和c/c++的通信，则情况就要复杂一些，主要是因为java中没有unsigned类型，并且java和c在某些数据类型上的长度不一致。

本文就是针对这种情况，整理了java数据类型和网络字节流或字节包(相当于java的byte 数组)之间转换方法。

实际上网上这方面的资料不少，但往往不全，甚至有些有错误，于是就花了点时间对java整型数和网络字节序的byte[]之间转换的各种情况做了一些验证和整理。

整理出来的函数如下：public class ByteConvert {// 以下是整型数和网络字节序的byte[] 数组之间的转换public static byte[] longToBytes(long n) {byte[] b = new byte[8];b[7] = (byte) (n & 0xff);b[6] = (byte) (n >> 8 & 0xff);b[5] = (byte) (n >> 16 & 0xff);b[4] = (byte) (n >> 24 & 0xff);b[3] = (byte) (n >> 32 & 0xff);b[2] = (byte) (n >> 40 & 0xff);b[1] = (byte) (n >> 48 & 0xff);b[0] = (byte) (n >> 56 & 0xff);return b;}public static void longT oBytes( long n, byte[] array, int offset ){array[7+offset] = (byte) (n & 0xff);array[6+offset] = (byte) (n >> 8 & 0xff);array[5+offset] = (byte) (n >> 16 & 0xff);array[4+offset] = (byte) (n >> 24 & 0xff);array[3+offset] = (byte) (n >> 32 & 0xff);array[2+offset] = (byte) (n >> 40 & 0xff);array[1+offset] = (byte) (n >> 48 & 0xff);array[0+offset] = (byte) (n >> 56 & 0xff);}public static long bytesToLong( byte[] array ){return ((((long) array[ 0] & 0xff) << 56)| (((long) array[ 1] & 0xff) << 48)| (((long) array[ 2] & 0xff) << 40)| (((long) array[ 3] & 0xff) << 32)| (((long) array[ 4] & 0xff) << 24)| (((long) array[ 5] & 0xff) << 16)| (((long) array[ 6] & 0xff) << 8)| (((long) array[ 7] & 0xff) << 0));}public static long bytesToLong( byte[] array, int offset ) {return ((((long) array[offset + 0] & 0xff) << 56)| (((long) array[offset + 1] & 0xff) << 48)| (((long) array[offset + 2] & 0xff) << 40)| (((long) array[offset + 3] & 0xff) << 32)| (((long) array[offset + 4] & 0xff) << 24)| (((long) array[offset + 5] & 0xff) << 16)| (((long) array[offset + 6] & 0xff) << 8)| (((long) array[offset + 7] & 0xff) << 0));}public static byte[] intToBytes(int n) {byte[] b = new byte[4];b[3] = (byte) (n & 0xff);b[2] = (byte) (n >> 8 & 0xff);b[1] = (byte) (n >> 16 & 0xff);b[0] = (byte) (n >> 24 & 0xff);return b;}public static void intToBytes( int n, byte[] array, int offset ){ array[3+offset] = (byte) (n & 0xff);array[2+offset] = (byte) (n >> 8 & 0xff);array[1+offset] = (byte) (n >> 16 & 0xff);array[offset] = (byte) (n >> 24 & 0xff);}public static int bytesToInt(byte b[]) {return b[3] & 0xff| (b[2] & 0xff) << 8| (b[1] & 0xff) << 16| (b[0] & 0xff) << 24;}public static int bytesToInt(byte b[], int offset) {return b[offset+3] & 0xff| (b[offset+2] & 0xff) << 8| (b[offset+1] & 0xff) << 16| (b[offset] & 0xff) << 24;}public static byte[] uintT oBytes( long n ){byte[] b = new byte[4];b[3] = (byte) (n & 0xff);b[2] = (byte) (n >> 8 & 0xff);b[1] = (byte) (n >> 16 & 0xff);b[0] = (byte) (n >> 24 & 0xff);return b;}public static void uintT oBytes( long n, byte[] array, int offset ){ array[3+offset] = (byte) (n );array[2+offset] = (byte) (n >> 8 & 0xff);array[1+offset] = (byte) (n >> 16 & 0xff);array[offset] = (byte) (n >> 24 & 0xff);}public static long bytesToUint(byte[] array) {return ((long) (array[3] & 0xff))| ((long) (array[2] & 0xff)) << 8| ((long) (array[1] & 0xff)) << 16| ((long) (array[0] & 0xff)) << 24;}public static long bytesToUint(byte[] array, int offset) { return ((long) (array[offset+3] & 0xff))| ((long) (array[offset+2] & 0xff)) << 8| ((long) (array[offset+1] & 0xff)) << 16| ((long) (array[offset] & 0xff)) << 24;}public static byte[] shortToBytes(short n) {byte[] b = new byte[2];b[1] = (byte) ( n & 0xff);b[0] = (byte) ((n >> 8) & 0xff);return b;}public static void shortT oBytes(short n, byte[] array, int offset ) { array[offset+1] = (byte) ( n & 0xff);array[offset] = (byte) ((n >> 8) & 0xff);}public static short bytesToShort(byte[] b){return (short)( b[1] & 0xff|(b[0] & 0xff) << 8 );}public static short bytesToShort(byte[] b, int offset){return (short)( b[offset+1] & 0xff|(b[offset] & 0xff) << 8 );}public static byte[] ushortToBytes(int n) {byte[] b = new byte[2];b[1] = (byte) ( n & 0xff);b[0] = (byte) ((n >> 8) & 0xff);return b;}public static void ushortToBytes(int n, byte[] array, int offset ) { array[offset+1] = (byte) ( n & 0xff);array[offset] = (byte) ((n >> 8) & 0xff);}public static int bytesToUshort(byte b[]) {return b[1] & 0xff| (b[0] & 0xff) << 8;}public static int bytesToUshort(byte b[], int offset) {return b[offset+1] & 0xff| (b[offset] & 0xff) << 8;}public static byte[] ubyteToBytes( int n ){byte[] b = new byte[1];b[0] = (byte) (n & 0xff);return b;}public static void ubyteToBytes( int n, byte[] array, int offset ){array[0] = (byte) (n & 0xff);}public static int bytesToUbyte( byte[] array ){return array[0] & 0xff;}public static int bytesToUbyte( byte[] array, int offset ){return array[offset] & 0xff;}// char 类型、float、double 类型和byte[] 数组之间的转换关系还需继续研究实现。