public class AppendStringTest {
       public static void main(String[] args) {
             String text="";
             long beginTime = System.currentTimeMillis();
             for(int i=0;i<10000; i++)
               text =text +1;
               long endTime = System.currentTimeMillis();            
             System.out.println("zhixingshijian:" + (endTime-beginTime));
             StringBuilder builder = new StringBuilder("");
              beginTime=System.currentTimeMillis();
               for(int i=0;i<10000; i++)
                 builder.append(String.valueOf(i));
               endTime = System.currentTimeMillis();
             System.out.println("zhixingshijian:" + (endTime-beginTime));
        }
}