各种进制转换byte,hex,string

public class ByteUtils {

	/**
	 * 2进制转16进制字符串
	 * @param bytes
	 * @return
	 */
	public static String byteToHexString(byte[] bytes){
		if(bytes==null){
			return null;
		}
        StringBuffer sb = new StringBuffer();   
        for (int i = 0; i < bytes.length; i++) {   
             String strHex=Integer.toHexString(bytes[i]);   
             if(strHex.length() > 3){   
                    sb.append(strHex.substring(6));   
             } else {   
                  if(strHex.length() < 2){   
                     sb.append("0" + strHex);   
                  } else {
                     sb.append(strHex);   
                  }   
             }   
        }   
       return  sb.toString();   
   } 
	
	/**
	 * 16进制字符串转2进制
	 * @param s
	 * @return
	 */
	public static byte[] hexStringToByte(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;
	}
	
	/**
	 * 字符转为byte
	 * @param c
	 * @return
	 */
	public static byte charToByte(char c) {
		return (byte) "0123456789ABCDEF".indexOf(c);
	}

	
	/**
	 * int to byte
	 * @param i
	 * @return
	 */
	public static byte[] intToByte(int i) { 
		byte[] bt = new byte[4]; 
		bt[0] = (byte) (0xff & i); 
		bt[1] = (byte) ((0xff00 & i) >> 8); 
		bt[2] = (byte) ((0xff0000 & i) >> 16); 
		bt[3] = (byte) ((0xff000000 & i) >> 24); 
		return bt; 
	}
	
	/**
	 * byte to int
	 * @param bytes
	 * @return
	 */
	public  static int bytesToInt(byte[] bytes) { 
		int num = bytes[0] & 0xFF; 
		num |= ((bytes[1] << 8) & 0xFF00); 
		num |= ((bytes[2] << 16) & 0xFF0000); 
		num |= ((bytes[3] << 24) & 0xFF000000); 
		return num;
	}
	
	/**  
     * 合并两个byte数组  
     * @param pByteA  合并在前
     * @param pByteB  合并在后
     * @return  
     */
    public static byte[] getMergeBytes(byte[] pByteA, byte[] pByteB){   
        int aCount = pByteA.length;   
        int bCount = pByteB.length;   
        byte[] b = new byte[aCount + bCount];   
        for(int i=0;i<aCount;i++){   
            b[i] = pByteA[i];   
        }   
        for(int i=0;i<bCount;i++){   
            b[aCount + i] = pByteB[i];   
        }   
        return b;
    } 
    
    /**  
     * 合并三个byte数组  
     * @param pByteA 合并前
     * @param pByteB 合并中
     * @param pByteC 合并后
     * @return 字节数组
     */
    public static byte[] getMergeBytes(byte[] pByteA, byte[] pByteB, byte[] pByteC){
    	
    	int aCount = pByteA.length;
    	int bCount = pByteB.length;
    	int cCount = pByteC.length;
        
    	byte[] b = new byte[aCount + bCount + cCount];   
        
        for(int i=0;i<aCount;i++){   
            b[i] = pByteA[i];   
        }   
        
        for(int i=0;i<bCount;i++){   
            b[aCount + i] = pByteB[i];   
        }
        
        for(int i=0;i<cCount;i++){   
            b[aCount + bCount + i] = pByteC[i];   
        }
        
        return b;
    }
    
    /**
     * 5个byte合并
     * @param a
     * @param b
     * @param c
     * @param d
     * @param e
     * @return
     */
    public static byte[] getMergeBytesFive(byte[] a, byte[] b , byte[] c , byte[] d , byte[] e){
    	
    	int ia = a.length;
    	int ib = b.length;
    	int ic = c.length;
    	int id = d.length;
    	int ie = e.length;

    	byte[] threeArr = new byte[ia+ib+ic];
    	threeArr = getMergeBytes(a, b, c);
    	
    	byte[] twoArr = new byte[id+ie];
    	twoArr = getMergeBytes(d, e);
    	
    	byte[] bs = new byte[ia+ib+ic+id+ie];
    	bs = getMergeBytes(threeArr, twoArr);
    	
    	return bs;
    }
    
    public static String bytesToString(byte[] bytes){
    	
    	StringBuffer sb = new StringBuffer(); 
		
    	for(int k=0; k<bytes.length; k++){
    		sb.append((char)bytes[k]);
		}
		
    	return sb.toString();
    }
    
    /**
     * char转化为byte
     * 
     * @param c
     * @return byte[]数组
     */
    public static byte[] charToByteArr(char c) {
        byte[] b = new byte[2];
        b[0] = (byte) ((c & 0xFF00) >> 8);
        b[1] = (byte) (c & 0xFF);
        return b;
    }
    
    /**
     * byte转换为char
     * 
     * @param b
     * @return
     */
    public static char byteToChar(byte[] b) {
        char c = (char) (((b[0] & 0xFF) << 8) | (b[1] & 0xFF));
        return c;
    }
}