public static void main(String[] args)throws Exception {
int a = 1;
String s = null;
System.out.println(new Date().getTime());
for(int i = 0; i < 1000000; i++){
s = a + "";
}
System.out.println(new Date().getTime());
for(int i = 0; i < 1000000; i++){
s = String.valueOf(i);
}
System.out.println(new Date().getTime());
}