java 字符串和二进制相互转换

二进制转换成字符串：

// 二进制转字符串
public static String byte2hex(byte[] b) 
{
   StringBuffer sb = new StringBuffer();
   String tmp = "";
   for (int i = 0; i < b.length; i++) {
    tmp = Integer.toHexString(b[i] & 0XFF);
    if (stmp.length() == 1){
    	sb.append("0" + tmp);
    }else{
    	sb.append(tmp);
    }
    
   }
   return sb.toString();
}

 

字符串转二进制：

// 字符串转二进制
public static byte[] hex2byte(String str) { 
  if (str == null){
   return null;
  }
  
  str = str.trim();
  int len = str.length();
  
  if (len == 0 || len % 2 == 1){
   return null;
  }
  
  byte[] b = new byte[len / 2];
  try {
	   for (int i = 0; i < str.length(); i += 2) {
	    	b[i / 2] = (byte) Integer.decode("0X" + str.substring(i, i + 2)).intValue();
	   }
	   return b;
  } catch (Exception e) {
   return null;
  }
}