多线程阻塞队列面试题

绝地灬酷狼 2022-07-13 12:38 201阅读 0赞

1.创建四个线程，打印16个日志对象，使用队列的方式。

public class Test {
        public static void main(String[] args) {
            BlockingQueue<String> queue=new ArrayBlockingQueue<String>(16);
            for(int i=0;i<4;i++){
                new Thread(new Runnable(){
                    @Override
                    public void run() {
                        while(true){
                            String logs;
                            try {
                                logs = queue.take();
                                Test.parseLog(logs);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }
    
                    }
    
                }).start();
            }
            System.out.println("begin:"+(System.currentTimeMillis()/1000));
            for(int i=0;i<16;i++){
                final String logs=""+(i+1);
                //Test.parseLog(logs);
                try {
                    queue.put(logs);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
        public static void parseLog(String log){
            System.out.println(log+":"+(System.currentTimeMillis()/1000));
        }
    
    }

2.一个生产者生产十个对象，创建十个消费者线程，每间隔一秒取一个对象，取对象的要按照生产的顺序。

package com.zyyw.service.dispatch;
    
    import java.util.concurrent.ArrayBlockingQueue;
    import java.util.concurrent.BlockingQueue;
    import java.util.concurrent.Semaphore;
    import java.util.concurrent.SynchronousQueue;
    
    
    public class Test { 
        public static void main(String[] args) {
            Semaphore order=new Semaphore(1);
            final SynchronousQueue<String> queue=new SynchronousQueue<String>();
            for(int i=0;i<10;i++){
                new Thread(new Runnable(){
                    @Override
                    public void run() {
                        try {
                            order.acquire();
                            String input=queue.take();
                            String output=TestDo.doSome(input);
                            System.out.println(Thread.currentThread().getName()+":"+output);
                            order.release();
                        } catch (Exception e) {
                            e.printStackTrace();
                        }               
                    }
                }).start();
            }
            System.out.println("begin:"+(System.currentTimeMillis()/1000));
            for(int i=0;i<10;i++){
                String input=i+"";
                try {
                    queue.put(input);
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
    class TestDo{
        public static String doSome(String input){
            try{
                Thread.sleep(1000);
            }catch(Exception e){
                e.printStackTrace();
            }
            String output=input+"："+(System.currentTimeMillis()/1000);
            return output;
        }
    }