Java各种数据类型之间的转化

public class TypeConvert {public static String getString(byte[] src, int srcPos, int destPos,int length) {byte[] tmp = new byte[length];System.arraycopy(src, srcPos, tmp, destPos, length);return (new String(tmp).trim());}public static String byte2String(byte buf[], int offset) {int pos = offset;for (; offset < buf.length; offset++)if (buf[offset] == 0)break;if (offset > pos)offset--;else if (offset == pos)return "";int len = (offset - pos) + 1;byte bb[] = new byte[len];System.arraycopy(buf, pos, bb, 0, len);String str = new String(bb);return str;}public static int byte2int(byte b[]) {return b[3] & 0xff | (b[2] & 0xff) << 8 | (b[1] & 0xff) << 16| (b[0] & 0xff) << 24;}public static int byte2int(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 long byte2long(byte b[], int offset) {return (long) b[offset + 7] & 255L | ((long) b[offset + 6] & 255L) << 8| ((long) b[offset + 5] & 255L) << 16| ((long) b[offset + 4] & 255L) << 24| ((long) b[offset + 3] & 255L) << 32| ((long) b[offset + 2] & 255L) << 40| ((long) b[offset + 1] & 255L) << 48 | (long) b[offset] << 56;}public static long byte2long(byte b[]) {return (long) b[7] & 255L | ((long) b[6] & 255L) << 8| ((long) b[5] & 255L) << 16 | ((long) b[4] & 255L) << 24| ((long) b[3] & 255L) << 32 | ((long) b[2] & 255L) << 40| ((long) b[1] & 255L) << 48 | (long) b[0] << 56;}public static short byte2short(byte b[], int offset) {return (short) (b[offset + 1] & 0xff | (b[offset] & 0xff) << 8);}public static short byte2short(byte b[]) {return (short) (b[1] & 0xff | (b[0] & 0xff) << 8);}public static short byte2tinyint(byte b[], int offset) {return (short) (b[offset] & 0xff);}public static void int2byte(int n, byte buf[], int offset) {buf[offset] = (byte) (n >> 24);buf[offset + 1] = (byte) (n >> 16);buf[offset + 2] = (byte) (n >> 8);buf[offset + 3] = (byte) n;}public static void int2byte2(int n, byte buf[], int offset) {buf[offset] = (byte) (n >> 8);buf[offset + 1] = (byte) n;}public static void int2byte3(int n, byte buf[], int offset) {// buf[offset] = (byte)(n >> 8);buf[offset] = (byte) n;}public static byte[] int2byte(int n) {byte b[] = new byte[4];b[0] = (byte) (n >> 24);b[1] = (byte) (n >> 16);b[2] = (byte) (n >> 8);b[3] = (byte) n;return b;}public static void long2byte(long n, byte buf[], int offset) {buf[offset] = (byte) (int) (n >> 56);buf[offset + 1] = (byte) (int) (n >> 48);buf[offset + 2] = (byte) (int) (n >> 40);buf[offset + 3] = (byte) (int) (n >> 32);buf[offset + 4] = (byte) (int) (n >> 24);buf[offset + 5] = (byte) (int) (n >> 16);buf[offset + 6] = (byte) (int) (n >> 8);buf[offset + 7] = (byte) (int) n;}public static byte[] long2byte(long n) {byte b[] = new byte[8];b[0] = (byte) (int) (n >> 56);b[1] = (byte) (int) (n >> 48);b[2] = (byte) (int) (n >> 40);b[3] = (byte) (int) (n >> 32);b[4] = (byte) (int) (n >> 24);b[5] = (byte) (int) (n >> 16);b[6] = (byte) (int) (n >> 8);b[7] = (byte) (int) n;return b;}public static void short2byte(int n, byte buf[], int offset) {buf[offset] = (byte) (n >> 8);buf[offset + 1] = (byte) n;}public static byte[] short2byte(int n) {byte b[] = new byte[2];b[0] = (byte) (n >> 8);b[1] = (byte) n;return b;}}