byte和hexstring,int，string等的转换类

public class HexConversion {

	/**
	 * 16进制数的字符串转字节数组(16进制转字节数组)
	 *
	 * @param hexString
	 *            16进制字符串
	 * @return 字节数组
	 */
	public static byte[] hexStringToBytes(String hexString) {
		if (hexString == null || hexString.equals("")) {
			return null;
		}
		hexString = hexString.toUpperCase();
		int length = hexString.length() / 2;
		char[] hexChars = hexString.toCharArray();
		byte[] d = new byte[length];
		for (int i = 0; i < length; i++) {
			int pos = i * 2;
			d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
		}
		return d;
	}

	public static String bytesToString(byte[] bytes){
		int size=0;
		for(int i=0;i<bytes.length;i++){
			if(bytes[i]!=0){
				size++;
			}else{
				break;
			}
		}
		byte[] data=new byte[size];
		System.arraycopy(bytes, 0, data, 0, size);
		return new String(data);
	}

	/**
	 * 字符转字节
	 *
	 * @param c
	 *            字符
	 * @return byte 字节
	 */
	private static byte charToByte(char c) {
		return (byte) "0123456789ABCDEF".indexOf(c);
	}

	/**
	 * 字节转16进制字符串
	 *
	 * @param src
	 *            字节数组
	 * @return 16进制字符串
	 */
	public static String bytesToHexString(byte[] src) {
		StringBuilder stringBuilder = new StringBuilder("");
		if (src == null || src.length <= 0) {
			return null;
		}
		for (int i = 0; i < src.length; i++) {
			int v = src[i] & 0xFF;
			String hv = Integer.toHexString(v);
			if (hv.length() < 2) {
				stringBuilder.append(0);
			}
			stringBuilder.append(hv);
		}
		return stringBuilder.toString();
	}

	/**
	 * 字节转整型
	 *
	 * @param b 字节数组
	 * @return int型
	 */
	public static int byte2Int(byte[] b) {
		int intValue = 0;
		for (int i = 0; i < b.length; i++) {
			intValue += (b[i] & 0xFF) << (8 * (3 - i));
			//System.out.print("intvalue --- "+intValue+" ");
		}
		return intValue;
	}

	public static long dowrd2Long(byte[] bytes) {
		long unsignedLong=0;
		for(int i=0;i<bytes.length;i++){
			unsignedLong=(long)(unsignedLong|(0x000000FF & ((int) bytes[i]))<<(8*i));
		}
		return unsignedLong;
	}

	public static long byteTranLong(byte[] b) {
		long value = 0;
		for (int i = 0; i < b.length; i++) {
			value += (b[i] & 0xFF) << (8 * (3 - i));
		}
		return value;
	}

	/**
	 * 整形转字节数组
	 *
	 * @param num
	 *            整形
	 * @return 字节数组
	 */
	public static byte[] int2bytes(int num) {
		byte[] b = new byte[4];
		//int mask = 0xff;
		for (int i = 0; i < 4; i++) {
			b[i] = (byte) (num >>> (24 - i * 8));
		}
		return b;
	}

	/**
	 * 把4字节的数组转换成IP
	 *
	 * @param bytes
	 *            4个字节的字节数组
	 * @return 字符串IP地址
	 */
	// public static String bytes2Ip(byte[] bytes) {
	// String ip = "";
	// for (int i = 0; i < 4; i++) {
	// String tmp = String.valueOf(bytes[i]);
	// if (bytes[i] < 0) {
	// tmp = String.valueOf(127+Math.abs(bytes[i]));
	// }
	//
	// if (i < 3) {
	// ip += tmp + ".";
	// } else {
	// ip += tmp;
	//
	// }
	// }
	// return ip;
	// }
	public static String bytes2Ip(byte[] bytes) {
		String ip = "";
		for (int i=0;i<bytes.length;i++) {
			int inval = 0;
			inval += (bytes[i] & 0xFF);
			ip += inval + ".";
		}
		ip = ip.substring(0, ip.length() - 1);
		return ip;
	}

	/**
	 * IP地址转换字节数组
	 *
	 * @param ip
	 *            字符串
	 * @return 字节数组
	 */
	public static byte[] ip2Bytes(String ip) {
		String[] ips = ip.split("[.]");
		byte[] ipbs = new byte[4];
		// IP地址压缩成4字节,如果要进一步处理的话,就可以转换成一个int了.
		int j = 0;
		for (int i =0;i<ipbs.length;i++) {
			int m = Integer.parseInt(ips[j]);
			ipbs[i] = (byte) (m & 0xFF);
			j++;
			// byte b = (byte) m;
			// if (m > 127) {
			// b = (byte) (127 - m);
			// }
			// ipbs[i] = b;
		}
		return ipbs;
	}

	/**
	 * 字节数组转字符串
	 *
	 * @param bytes
	 *            字节数组/不足位补0的字节数组
	 * @return 字符串
	 */
	public static String bytes2String(byte[] bytes) {
		int beginIndex = 0;
		int endIndex=0;
		int length=0;
		// 判断是否补过0
		for (int i = 0; i < bytes.length; i++) {
			if (bytes[i] != 0) {
				beginIndex=i;
				break;
			}
		}
		for (int i = bytes.length-1; i >=0; i--) {
			if (bytes[i] != 0) {
				endIndex=i;
				break;
			}
		}
		if(endIndex<=beginIndex){
			length=0;
		}else{
			length=endIndex-beginIndex+1;
		}
		if(length==0){
			return "";
		}
		byte[] b=new byte[length];
		System.arraycopy(bytes, beginIndex, b, 0, length);
		return new String(b);
	}

	public static void main(String[] args) {

	}
}