java中字符串切割的方法总结

StringTokenizer最快 ，基本已经不用了，除非在某些需要效率的场合。
Scanner最慢。 
String和Pattern速度差不多。Pattern稍快些。 String和Pattern的split 方法效率相当，常用

 

public   static   void  main(String [] args){
long  start = System.currentTimeMillis();
for ( int  i= 0 ;i< 100000 ;i++){
        test1();
    }
long  end = System.currentTimeMillis();
    System.out.println("StringTokenzier: " +(end-start));
    start = System.currentTimeMillis();
for ( int  i= 0 ;i< 100000 ;i++){
        test2();
    }
    end = System.currentTimeMillis();
    System.out.println("Scanner: " +(end-start));
    start = System.currentTimeMillis();
for ( int  i= 0 ;i< 100000 ;i++){
        test3();
    }
    end = System.currentTimeMillis();
    System.out.println("String: " +(end-start));
    start = System.currentTimeMillis();
for ( int  i= 0 ;i< 100000 ;i++){
        test4();
    }
    end = System.currentTimeMillis();
    System.out.println("Pattern: " +(end-start));
}
//用StringTokenizer
public   static   void  test1(){
    String input = "This is 1 just a test" ;
    StringTokenizer st = new  StringTokenizer(input);
while (st.hasMoreTokens()){
        String s = st.nextToken();
    }
}
//用Scanner的方法
public   static   void  test2(){
    String input = "This is 1 just a test" ;
    Scanner scanner = new  Scanner(input);
    scanner.useDelimiter(" " );
while (scanner.hasNext()){
        String s = scanner.next();
    }
}
//用String的split方法
public   static   void  test3(){
    String input = "This is 1 just a test" ;
    String [] str = input.split(" " );
for ( int  i= 0 ;i<str.length;i++){
        String s = str[i];
    }
}
//用Pattern的方法
public   static   void  test4(){
    Pattern pattern = Pattern.compile(" " );
    String input = "This is 1 just a test" ;
    String [] str = pattern.split(input);
for ( int  i= 0 ;i<str.length;i++){
        String s = str[i];
    }
}

       public static void main(String [] args){
    long start = System.currentTimeMillis();
    for(int i=0;i<100000;i++){
        test1();
    }
    long end = System.currentTimeMillis();
    System.out.println("StringTokenzier: "+(end-start));

    start = System.currentTimeMillis();
    for(int i=0;i<100000;i++){
        test2();
    }
    end = System.currentTimeMillis();
    System.out.println("Scanner: "+(end-start));

    start = System.currentTimeMillis();
    for(int i=0;i<100000;i++){
        test3();
    }
    end = System.currentTimeMillis();
    System.out.println("String: "+(end-start));

    start = System.currentTimeMillis();
    for(int i=0;i<100000;i++){
        test4();
    }
    end = System.currentTimeMillis();
    System.out.println("Pattern: "+(end-start));
}
       //用StringTokenizer
public static void test1(){
    String input = "This is 1 just a test";
    StringTokenizer st = new StringTokenizer(input);
    while(st.hasMoreTokens()){
        String s = st.nextToken();
    }
}
//用Scanner的方法
public static void test2(){
    String input = "This is 1 just a test";
    Scanner scanner = new Scanner(input);
    scanner.useDelimiter(" ");
    while(scanner.hasNext()){
        String s = scanner.next();
    }
}
//用String的split方法
public static void test3(){
    String input = "This is 1 just a test";
    String [] str = input.split(" ");
    for(int i=0;i<str.length;i++){
        String s = str[i];
    }
}
//用Pattern的方法
public static void test4(){
    Pattern pattern = Pattern.compile(" ");
    String input = "This is 1 just a test";
    String [] str = pattern.split(input);
    for(int i=0;i<str.length;i++){
        String s = str[i];
    }
}

运行了五次。输出结果如下：

 StringTokenzier:  110
Scanner: 3281
String: 453
Pattern: 438

StringTokenzier: 109
Scanner: 3297
String: 453
Pattern: 438

StringTokenzier: 110
Scanner: 3265
String: 485
Pattern: 437

StringTokenzier: 109
Scanner: 3266
String: 469
Pattern: 437

StringTokenzier: 109
Scanner: 3297
String: 469
Pattern: 422

 StringTokenzier: 110
Scanner: 3281
String: 453
Pattern: 438

StringTokenzier: 109
Scanner: 3297
String: 453
Pattern: 438

StringTokenzier: 110
Scanner: 3265
String: 485
Pattern: 437

StringTokenzier: 109
Scanner: 3266
String: 469
Pattern: 437

StringTokenzier: 109
Scanner: 3297
String: 469
Pattern: 422

StringTokenizer最快 
Scanner最慢。 
String和Pattern速度差不多。Pattern稍快些。