import java.math.BigInteger;
public class Util
{
/**
* 整形转换成网络传输的字节流（字节数组）型数据
*
* @param num 一个整型数据
* @return 4个字节的自己数组
*/
public static byte[] intToBytes(int num)
{
byte[] bytes = new byte[4];
bytes[0] = (byte) (0xff & (num >> 0));
bytes[1] = (byte) (0xff & (num >> 8));
bytes[2] = (byte) (0xff & (num >> 16));
bytes[3] = (byte) (0xff & (num >> 24));
return bytes;
}
/**
* 四个字节的字节数据转换成一个整形数据
*
* @param bytes 4个字节的字节数组
* @return 一个整型数据
*/
public static int byteToInt(byte[] bytes)
{
int num = 0;
int temp;
temp = (0x000000ff & (bytes[0])) << 0;
num = num | temp;
temp = (0x000000ff & (bytes[1])) << 8;
num = num | temp;
temp = (0x000000ff & (bytes[2])) << 16;
num = num | temp;
temp = (0x000000ff & (bytes[3])) << 24;
num = num | temp;
return num;
}
/**
* 长整形转换成网络传输的字节流（字节数组）型数据
*
* @param num 一个长整型数据
* @return 4个字节的自己数组
*/
public static byte[] longToBytes(long num)
{
byte[] bytes = new byte[8];
for (int i = 0; i < 8; i++)
{
bytes[i] = (byte) (0xff & (num >> (i * 8)));
}
return bytes;
}
/**
* 大数字转换字节流（字节数组）型数据
*
* @param n
* @return
*/
public static byte[] byteConvert32Bytes(BigInteger n)
{
byte tmpd[] = (byte[])null;
if(n == null)
{
return null;
}
if(n.toByteArray().length == 33)
{
tmpd = new byte[32];
System.arraycopy(n.toByteArray(), 1, tmpd, 0, 32);
}
else if(n.toByteArray().length == 32)
{
tmpd = n.toByteArray();
}
else
{
tmpd = new byte[32];
for(int i = 0; i < 32 - n.toByteArray().length; i++)
{
tmpd[i] = 0;
}
System.arraycopy(n.toByteArray(), 0, tmpd, 32 - n.toByteArray().length, n.toByteArray().length);
}
return tmpd;
}
/**
* 换字节流（字节数组）型数据转大数字
*
* @param b
* @return
*/
public static BigInteger byteConvertInteger(byte[] b)
{
if (b[0] < 0)
{
byte[] temp = new byte[b.length + 1];
temp[0] = 0;
System.arraycopy(b, 0, temp, 1, b.length);
return new BigInteger(temp);
}
return new BigInteger(b);
}
/**
* 根据字节数组获得值(十六进制数字)
*
* @param bytes
* @return
*/
public static String getHexString(byte[] bytes)
{
return getHexString(bytes, true);
}
/**
* 根据字节数组获得值(十六进制数字)
*
* @param bytes
* @param upperCase
* @return
*/
public static String getHexString(byte[] bytes, boolean upperCase)
{
String ret = "";
for (int i = 0; i < bytes.length; i++)
{
ret += Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1);
}
return upperCase ? ret.toUpperCase() : ret;
}
/**
* 打印十六进制字符串
*
* @param bytes
*/
public static void printHexString(byte[] bytes)
{
for (int i = 0; i < bytes.length; i++)
{
String hex = Integer.toHexString(bytes[i] & 0xFF);
if (hex.length() == 1)
{
hex = '0' + hex;
}
System.out.print("0x" + hex.toUpperCase() + ",");
}
System.out.println("");
}
/**
* Convert hex string to byte[]
*
* @param hexString
* the hex string
* @return byte[]
*/
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;
}
/**
* Convert char to byte
*
* @param c
* char
* @return byte
*/
public static byte charToByte(char c)
{
return (byte) "0123456789ABCDEF".indexOf(c);
}
/**
* 用于建立十六进制字符的输出的小写字符数组
*/
private static final char[] DIGITS_LOWER = {'0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
/**
* 用于建立十六进制字符的输出的大写字符数组
*/
private static final char[] DIGITS_UPPER = {'0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
/**
* 将字节数组转换为十六进制字符数组
*
* @param data byte[]
* @return 十六进制char[]
*/
public static char[] encodeHex(byte[] data) {
return encodeHex(data, true);
}
/**
* 将字节数组转换为十六进制字符数组
*
* @param data byte[]
* @param toLowerCase <code>true</code> 传换成小写格式 ， <code>false</code> 传换成大写格式
* @return 十六进制char[]
*/
public static char[] encodeHex(byte[] data, boolean toLowerCase) {
return encodeHex(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
}
/**
* 将字节数组转换为十六进制字符数组
*
* @param data byte[]
* @param toDigits 用于控制输出的char[]
* @return 十六进制char[]
*/
protected static char[] encodeHex(byte[] data, char[] toDigits) {
int l = data.length;
char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++) {
out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
out[j++] = toDigits[0x0F & data[i]];
}
return out;
}
/**
* 将字节数组转换为十六进制字符串
*
* @param data byte[]
* @return 十六进制String
*/
public static String encodeHexString(byte[] data) {
return encodeHexString(data, true);
}
/**
* 将字节数组转换为十六进制字符串
*
* @param data byte[]
* @param toLowerCase <code>true</code> 传换成小写格式 ， <code>false</code> 传换成大写格式
* @return 十六进制String
*/
public static String encodeHexString(byte[] data, boolean toLowerCase) {
return encodeHexString(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
}
/**
* 将字节数组转换为十六进制字符串
*
* @param data byte[]
* @param toDigits 用于控制输出的char[]
* @return 十六进制String
*/
protected static String encodeHexString(byte[] data, char[] toDigits) {
return new String(encodeHex(data, toDigits));
}
/**
* 将十六进制字符数组转换为字节数组
*
* @param data 十六进制char[]
* @return byte[]
* @throws RuntimeException 如果源十六进制字符数组是一个奇怪的长度，将抛出运行时异常
*/
public static byte[] decodeHex(char[] data) {
int len = data.length;
if ((len & 0x01) != 0) {
throw new RuntimeException("Odd number of characters.");
}
byte[] out = new byte[len >> 1];
// two characters form the hex value.
for (int i = 0, j = 0; j < len; i++) {
int f = toDigit(data[j], j)
