支付宝面试题： 30秒内限制某方法被调用100次（一个时间段限制方法被调用的次数）

旧城等待， 2022-08-26 11:25 146阅读 0赞

# 假设一个Class的方法 a，被限定30秒内只能被调用100次，如何实现。 #

# 1、定义调用接口Icallee #

public interface Icallee \{  
  
  
public void play();  
\}

# 2、实现调用接口类 #

public class Callee implements Icallee \{  
  
  
@Override  
public void play() \{  
// TODO Auto-generated method stub  
System.out.println(" Hello...The method is being called. ");  
\}  
  
  
\}

# 3、限制一段时间内方法调用次数类 #

public  class CheckCalledTimesInPeriod \{  
  
  
private Icallee callee;   
  
private  int limitTime;  
   
private  long startMills;  
  
private  int limitCount;  
  
  
// record the times that be called  
static private int count = 0 ;    
   
public CheckCalledTimesInPeriod(int minute,long startMills,int limitCount)\{  
       this.limitTime= minute;  
       this.startMills = startMills;  
       this.limitCount = limitCount;       
       callee = new Callee();  
   \}  
   
//Limit the times that be called for a period  
public  synchronized void execute()\{  
    
    long nowMills = System.currentTimeMillis();    
     
    count++;  
  
    if(nowMills<=(startMills+limitTime\*60000)&&count<=limitCount)   
    \{  
    callee.play();  
    \}  
     
    //to Log the times  
    Calendar c = Calendar.getInstance();   
    DateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");  
    CallerRunning.sb.append("You are calling = "+count+" times. The time is = "+format.format(c.getTime())+"\\r\\n");  
System.out.println("You are calling "+count+" times."+"The Time is = "+format.format(c.getTime()));  
     
   \}  
     
\}

# 4、测试运行类 #

public class CallerRunning \{  
  
  
// to store the log  data    
static public   StringBuffer sb = new StringBuffer();  
/\*\*  
\* @param args  
\*/  
public static void main(String\[\] args) \{  
   
  
        long startMills = System.currentTimeMillis();  
    long nowMills = startMills ;  
     
    //call a method 60000 times in 1 minute   
    CheckCalledTimesInPeriod called = new CheckCalledTimesInPeriod(1, startMills, 60000);  
     
    //to log the running time  
    Calendar c = Calendar.getInstance();   
DateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");  
   sb.append("begin time is = "+format.format(c.getTime())+"\\r\\n");  
     
   //test run  in 6 second  
    while(nowMills<=(startMills+6000))  
    \{  
     
          nowMills = System.currentTimeMillis();  
          called.execute();  
    \}  
     
    //to write the log to txt  
    Calendar d = Calendar.getInstance();   
    sb.append("end time is = "+format.format(d.getTime())+"\\r\\n");  
    writeTxt("C:\\\\test.txt", sb.toString());  
\}  
  
  
public static void writeTxt(String filePath, String content)\{  
  
       try \{    
           File f = new File(filePath);    
           if (!f.exists()) \{    
               f.createNewFile();// 不存在则创建    
           \}    
           BufferedWriter output = new BufferedWriter(new FileWriter(f));    
           output.write(content);    
           output.close();    
       \} catch (Exception e) \{    
           e.printStackTrace();    
   
       \}    
\}  
  
  
\}

# 5、TXT文件结果 LOG  #

begin time is = 2014-04-04 04:21:22  
You are calling = 1 times. The time is = 2014-04-04 04:21:22  
You are calling = 2 times. The time is = 2014-04-04 04:21:22  
You are calling = 3 times. The time is = 2014-04-04 04:21:22  
You are calling = 4 times. The time is = 2014-04-04 04:21:22  
You are calling = 5 times. The time is = 2014-04-04 04:21:22  
You are calling = 6 times. The time is = 2014-04-04 04:21:22  
You are calling = 7 times. The time is = 2014-04-04 04:21:22  
You are calling = 8 times. The time is = 2014-04-04 04:21:22  
You are calling = 9 times. The time is = 2014-04-04 04:21:22  
You are calling = 10 times. The time is = 2014-04-04 04:21:22  
You are calling = 11 times. The time is = 2014-04-04 04:21:22  
You are calling = 12 times. The time is = 2014-04-04 04:21:22  
You are calling = 13 times. The time is = 2014-04-04 04:21:22  
You are calling = 14 times. The time is = 2014-04-04 04:21:22  
You are calling = 15 times. The time is = 2014-04-04 04:21:22  
You are calling = 16 times. The time is = 2014-04-04 04:21:22  
You are calling = 17 times. The time is = 2014-04-04 04:21:22  
You are calling = 18 times. The time is = 2014-04-04 04:21:22  
You are calling = 19 times. The time is = 2014-04-04 04:21:22  
You are calling = 20 times. The time is = 2014-04-04 04:21:22  
You are calling = 21 times. The time is = 2014-04-04 04:21:22  
You are calling = 22 times. The time is = 2014-04-04 04:21:22  
You are calling = 23 times. The time is = 2014-04-04 04:21:22  
You are calling = 24 times. The time is = 2014-04-04 04:21:22  
You are calling = 25 times. The time is = 2014-04-04 04:21:22  
You are calling = 26 times. The time is = 2014-04-04 04:21:22  
You are calling = 27 times. The time is = 2014-04-04 04:21:22  
You are calling = 28 times. The time is = 2014-04-04 04:21:22  
You are calling = 29 times. The time is = 2014-04-04 04:21:22  
You are calling = 30 times. The time is = 2014-04-04 04:21:22  
You are calling = 31 times. The time is = 2014-04-04 04:21:22  
You are calling = 32 times. The time is = 2014-04-04 04:21:22  
You are calling = 33 times. The time is = 2014-04-04 04:21:22  
You are calling = 34 times. The time is = 2014-04-04 04:21:22  
You are calling = 35 times. The time is = 2014-04-04 04:21:22  
You are calling = 36 times. The time is = 2014-04-04 04:21:22  
You are calling = 37 times. The time is = 2014-04-04 04:21:22  
You are calling = 38 times. The time is = 2014-04-04 04:21:22  
You are calling = 39 times. The time is = 2014-04-04 04:21:22  
You are calling = 40 times. The time is = 2014-04-04 04:21:22

。。。。。。。。。。。。。。。。。。。。。。。。。。。。