//待转化的超大二进制正整数
String s = "" + Long.MAX_VALUE;
BigInteger TWO = new BigInteger("2");
BigInteger ZERO = new BigInteger("0");
BigInteger b1 = new BigInteger(s);
String temp;
StringBuffer sb = new StringBuffer();
do {
temp = b1.remainder(TWO).toString();
sb.append(temp);
} while((b1 = b1.divide(TWO)).compareTo(ZERO) != 0);
System.out.println(s + "的二进制为:\n" + sb.reverse());
9223372036854775807的二进制为: 111111111111111111111111111111111111111111111111111111111111111