Java decimal to binary, octal, hexadecimal string

Decimal to binary

class DecToBin
{
 public static void main(String[] args) 
 {
 //System.out.println("Hello World!");
 long dec = -9223372036854775807l;
 // -9223372036854775808 这个数不行，不要试，嘿嘿
 String binStr="";
 long decAbs=Math.abs(dec);
 while (decAbs>0)
 { binStr=(decAbs&1)+binStr;
 decAbs>>=1;
 }
 binStr= dec<0?"-"+binStr:dec==0?"0":binStr;

 System.out.println(binStr);
 }
}