Java示例字符串优化

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");

   }

}