如何比较字符串创建的性能呢？

解决方法

下面的示例以两种不同方式创建两个字符串的性能进行比较。

public class StringComparePerformance{
   public static void main(String[] args){      
      long startTime = System.currentTimeMillis();
      for(int i=0;i<50000;i++){
         String s1 = "hello";
         String s2 = "hello"; 
      }
      long endTime = System.currentTimeMillis();
      System.out.println("Time taken for creation" 
      + " of String literals : "+ (endTime - startTime) 
      + " milli seconds" );       
      long startTime1 = System.currentTimeMillis();
      for(int i=0;i<50000;i++){
         String s3 = new String("hello");
         String s4 = new String("hello");
      }
      long endTime1 = System.currentTimeMillis();
      System.out.println("Time taken for creation" 
      + " of String objects : " + (endTime1 - startTime1)
      + " milli seconds");
   }
}

结果

上面的代码示例将产生以下结果。该结果可能会不同。

Time taken for creation of String literals : 0 milli seconds
Time taken for creation of String objects : 16 milli seconds