模板方式设计模式

/**
* 统计不同操作的耗时，String拼接一万次的时间，int加和一万次的时间
* System.currentTimeMillis();获取当前时间
*/
public class IntDemo extends TimeTemplate {

    @Override
    public void doWork(){

        int num = 1;
        for (int i = 0; i < 1000000 ; i++) {
            num += 1;
        }

    }
}

public class StringDemo extends TimeTemplate {

    @Override
    public void doWork(){

        String str = "";
        for (int i = 0; i < 10000 ; i++) {
            str += 1;
        }

    }
}

//模板类
public abstract class TimeTemplate implements Time {

    final public long getTotalTime(){
        long begin = System.currentTimeMillis();

        this.doWork();

        long end = System.currentTimeMillis();
        return end - begin;
    }

public interface Time {
    /**
     * 统计时间的接口
     */
    void doWork();
}
    
public class Test {
    public static void main(String[] args) {
        StringDemo stringDemo = new StringDemo();
        long strTime = stringDemo.getTotalTime();
        System.out.println("str耗时：" + strTime);

        IntDemo intDemo = new IntDemo();
        long intTime = stringDemo.getTotalTime();
        System.out.println("int耗时：" + intTime);
    }
}