Java 字符串优化

public class StringOptimization {
   public static void main(String[] args) {
      String variables[] = new String[50000];     
      for( int i = 0;i <50000;i++) {
         variables[i] = "s"+i;
      }
      long startTime0 = System.currentTimeMillis();

      for(int i = 0;i<50000;i++) {
         variables[i] = "hello";
      }
      long endTime0 = System.currentTimeMillis();
      System.out.println("Creation time"
         + " of String literals : "+ (endTime0 - startTime0)
         + " ms" );
      long startTime1 = System.currentTimeMillis();

      for(int i = 0;i<50000;i++) {
         variables[i] = new String("hello");
      }
      long endTime1 = System.currentTimeMillis();
      System.out.println("Creation time of"
         + " String objects with 'new' key word : "
         + (endTime1 - startTime1)
         + " ms");
      long startTime2 = System.currentTimeMillis();

      for(int i = 0;i<50000;i++) {
         variables[i] = new String("hello");
         variables[i] = variables[i].intern();        
      }
      long endTime2 = System.currentTimeMillis();
      System.out.println("Creation time of"
         + " String objects with intern(): "
         + (endTime2 - startTime2)
         + " ms");
   }
}