apache的replace,trim方法 StringUtils.replace(),StringUtils.trimWhitespace() java原生

apache的replace,trim方法 StringUtils.replace(),StringUtils.trimWhitespace() 
java原生的replace,trim方法之间性能的巨大差别。 

public class App
{
    final static String teString = "    555555599999999999999999aaa sss ssaaaaaaaaaaaaaatasdtatastasrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrraaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa      ";
    public static void main( String[] args )
    {
        int t = 100000;
         long start1 = System.nanoTime();
         long stringUtilsReplaceTime = 0;
         long stringUtilsTrimTime = 0;
         long stringReplaceTime = 0;
         long stringTrimTime = 0;
         for(int i= 0;i<t;i++){
           StringUtils.replace(teString,"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","b");
         }
         stringUtilsReplaceTime= System.nanoTime()-start1;


          start1 = System.nanoTime();
         for(int i= 0;i<t;i++){
           teString.replace("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "b");
         }

         stringReplaceTime = System.nanoTime()-start1;

        start1 = System.nanoTime();
       for(int i= 0;i<t;i++){
           teString.trim();
       }
       stringTrimTime = System.nanoTime()-start1;


        start1 = System.nanoTime();
       for(int i= 0;i<t;i++){

           StringUtils.trimWhitespace(teString);
       }

       stringUtilsTrimTime = System.nanoTime()-start1;

       System.out.println("stringUtilsReplaceTime:"+stringUtilsReplaceTime);
       System.out.println("stringReplaceTime     :"+stringReplaceTime);
       System.out.println("stringUtilsTrimTime   :"+stringUtilsTrimTime);
       System.out.println("stringTrimTime        :"+stringTrimTime);
    }

}

输出结果为： 
stringUtilsReplaceTime:293389595 
stringReplaceTime     :1019421816 
stringUtilsTrimTime   :176730378 
stringTrimTime        :3888271 

public class App
{
    final static String teString = "    555555599999999999999999aaa sss ssaaaaaaaaaaaaaatasdtatastasrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrraaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa      ";
    public static void main( String[] args )
    {
        int t = 100;
         long start1 = System.nanoTime();
         long stringUtilsReplaceTime = 0;
         long stringUtilsTrimTime = 0;
         long stringReplaceTime = 0;
         long stringTrimTime = 0;
         for(int i= 0;i<t;i++){
           StringUtils.replace(teString,"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","b");
         }
         stringUtilsReplaceTime= System.nanoTime()-start1;


          start1 = System.nanoTime();
         for(int i= 0;i<t;i++){
           teString.replace("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "b");
         }

         stringReplaceTime = System.nanoTime()-start1;

        start1 = System.nanoTime();
       for(int i= 0;i<t;i++){
           teString.trim();
       }
       stringTrimTime = System.nanoTime()-start1;


        start1 = System.nanoTime();
       for(int i= 0;i<t;i++){

           StringUtils.trimWhitespace(teString);
       }

       stringUtilsTrimTime = System.nanoTime()-start1;

       System.out.println("stringUtilsReplaceTime:"+stringUtilsReplaceTime);
       System.out.println("stringReplaceTime     :"+stringReplaceTime);
       System.out.println("stringUtilsTrimTime   :"+stringUtilsTrimTime);
       System.out.println("stringTrimTime        :"+stringTrimTime);
    }

}

结果为： 
stringUtilsReplaceTime:94864540 
stringReplaceTime     :8341259 
stringUtilsTrimTime   :953821 
stringTrimTime        :57856 

评论

2 楼 lurenjiaxxy 2013-11-15  

我这边测下来可是StringUtils比较快，StringUtils.trimWhitespace() 这个也没有，不知道你用的啥版本。。。。。。

1 楼 cgddm 2013-04-28