HexUtil工具类

/** 
 * 进制转化 
 * @author  
 * 
 */  
public class HexUtil {  
  
    /** 
     * 二进制byte数组转十六进制byte数组 
     * byte array to hex 
     * 
     * @param b byte array 
     * @return hex string 
     */  
    public static String byte2hex(byte[] b) {  
        StringBuilder hs = new StringBuilder();  
        String stmp;  
        for (int i = 0; i < b.length; i++) {  
            stmp = Integer.toHexString(b[i] & 0xFF).toUpperCase();  
            if (stmp.length() == 1) {  
                hs.append("0").append(stmp);  
            } else {  
                hs.append(stmp);  
            }  
        }  
        return hs.toString();  
    }  
  
    /** 
     * 十六进制byte数组转二进制byte数组 
     * hex to byte array 
     * 
     * @param hex hex string 
     * @return byte array 
     */  
    public static byte[] hex2byte(String hex)  
             throws IllegalArgumentException{  
        if (hex.length() % 2 != 0) {  
            throw new IllegalArgumentException ("invalid hex string");  
        }  
        char[] arr = hex.toCharArray();  
        byte[] b = new byte[hex.length() / 2];  
        for (int i = 0, j = 0, l = hex.length(); i < l; i++, j++) {  
            String swap = "" + arr[i++] + arr[i];  
            int byteint = Integer.parseInt(swap, 16) & 0xFF;  
            b[j] = new Integer(byteint).byteValue();  
        }  
        return b;  
    }  
      
    public static void main(String[] args) {  
        String str1 = "abcedefghijklmnopqrstuvwxyz";  
        //String str1 = "1";  
        String hexStr = HexUtil.byte2hex(str1.getBytes());  
        System.out.println(hexStr);  
        String str2 = new String(HexUtil.hex2byte(hexStr));  
        System.out.println(str2);  
        System.out.println(str1.equals(str2));  
    }  
      
}