byte[] binary = new byte[256];
StringBuffer = new StringBuffer(binary.length * 2);
for(int i=0; i<binary.length; i++){
　　buffer.append(Character.forDigit((binary >> 4) & 0x0F, 16));
　　buffer.append(Character.forDigit((binary >> 0) & 0x0F, 16));
}
String hex = buffer.toString();