Java-Queue总结

import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

//底层链表实现  队列，先进先出
public class Test_03_ConcurrentLinkedQueue {
	public static void main(String[] args) {
		Queue<String> queue = new ConcurrentLinkedQueue<>();
		for (int i = 0; i < 10; i++) {
			queue.offer("value" + i);
		}
		System.out.println(queue);
		System.out.println(queue.size());
		
		//peek()  查看queue中的首数据
		System.out.println(queue.peek());
		System.out.println(queue.size());
		
		//poll()->获取queue首数据
		System.out.println(queue.poll());
		System.out.println(queue.size());
	}
}

import java.util.Random;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;

/** 并发容器 - LinkedBlockingQueue
*  阻塞容器。
*  put & take - 自动阻塞。
*  put自动阻塞， 队列容量满后，自动阻塞
*  take自动阻塞方法， 队列容量为0后，自动阻塞。
*/
public class Test_04_LinkBlockingQueue {
	final BlockingQueue<String> queue = new LinkedBlockingQueue<>();
	final Random r = new Random();
	
	public static void main(String[] args) {
		final Test_04_LinkBlockingQueue t = new Test_04_LinkBlockingQueue();
		
		new Thread(new Runnable() {
			@Override
			public void run() {
				while(true){
					try {
						t.queue.put("value"+t.r.nextInt(1000));
						TimeUnit.SECONDS.sleep(1);
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
			}
		}, "producer").start();
		
		for(int i = 0; i < 3; i++){
			new Thread(new Runnable() {
				@Override
				public void run() {
					while(true){
						try {
							System.out.println(Thread.currentThread().getName() + 
									" - " + t.queue.take());
						} catch (InterruptedException e) {
							e.printStackTrace();
						}
					}
				}
			}, "consumer"+i).start();
		}
	}
}

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;

public class Test_05_ArrayBlockingQueue {
	//当容量不足的时候，有阻塞能力
	//add 方法在容量不足的时候，抛出异常
	//put 方法在容量不如的时候，阻塞等待
	//offer 方法，单参数，容量不足的时候，返回false。当前新增数据操作放弃
	//offer 三参数，容量不足的时候，阻塞times时长（单位为timeunit）,如果在阻塞时长内,
	//有容量空闲，新增数据返回true，如果阻塞时长范围内，无容量空闲，放弃新增数据，返回false
	
	final BlockingQueue<String> queue = new ArrayBlockingQueue<>(3);

	public static void main(String[] args) {
		final Test_05_ArrayBlockingQueue t = new Test_05_ArrayBlockingQueue();

		for (int i = 0; i < 5; i++) {
			// System.out.println("add method : " + t.queue.add("value"+i));
			/*
			 * try { t.queue.put("put"+i); } catch (InterruptedException e) {
			 * e.printStackTrace(); } System.out.println("put method : " + i);
			 */
			// System.out.println("offer method : " + t.queue.offer("value"+i));
			try {
				System.out.println("offer method : " + t.queue.offer("value" + i, 1, TimeUnit.SECONDS));
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		System.out.println(t.queue);
	}
}

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;

//有顺序有时间的排序
//延时队列，根据比较机制，实现自定义处理顺序的队列。常用于定时任务
public class Test_06_DelayQueue {
	static BlockingQueue<MyTask_06> queue = new DelayQueue<>();

	public static void main(String[] args) throws InterruptedException {
		long value = System.currentTimeMillis();
		MyTask_06 task1 = new MyTask_06(value + 2000);
		MyTask_06 task2 = new MyTask_06(value + 1000);
		MyTask_06 task3 = new MyTask_06(value + 3000);
		MyTask_06 task4 = new MyTask_06(value + 2500);
		MyTask_06 task5 = new MyTask_06(value + 1500);

		queue.put(task1);
		queue.put(task2);
		queue.put(task3);
		queue.put(task4);
		queue.put(task5);

		System.out.println(queue);
		System.out.println(value);
		for (int i = 0; i < 5; i++) {
			System.out.println(queue.take());
		}
	}
}

class MyTask_06 implements Delayed {

	private long compareValue;

	public MyTask_06(long compareValue) {
		this.compareValue = compareValue;
	}

	/**
	 * 比较大小。自动实现升序 建议和getDelay方法配合完成。
	 * 如果在DelayQueue是需要按时间完成的计划任务，必须配合getDelay方法完成。
	 */
	@Override
	public int compareTo(Delayed o) {
		return (int) (this.getDelay(TimeUnit.MILLISECONDS) - o.getDelay(TimeUnit.MILLISECONDS));
	}

	/**
	 * 获取计划时长的方法。 根据参数TimeUnit来决定，如何返回结果值。
	 */
	@Override
	public long getDelay(TimeUnit unit) {
		return unit.convert(compareValue - System.currentTimeMillis(), TimeUnit.MILLISECONDS);
	}

	@Override
	public String toString() {
		return "Task compare value is : " + this.compareValue;
	}
}

/**
 * 并发容器 - LinkedTransferQueue
 *  转移队列
 *  add - 队列会保存数据，不做阻塞等待。
 *  transfer - 是TransferQueue的特有方法。必须有消费者（take()方法的调用者）。
 *   如果没有任意线程消费数据，transfer方法阻塞。一般用于处理即时消息。
 */
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TransferQueue;

public class Test_07_TransferQueue {
	TransferQueue<String> queue = new LinkedTransferQueue<>();

	public static void main(String[] args) {
		final Test_07_TransferQueue t = new Test_07_TransferQueue();

		/*
		 * new Thread(new Runnable() {
		 * 
		 * @Override public void run() { try {
		 * System.out.println(Thread.currentThread().getName() +
		 * " thread begin " );
		 * System.out.println(Thread.currentThread().getName() + " - " +
		 * t.queue.take()); } catch (InterruptedException e) {
		 * e.printStackTrace(); } } }, "output thread").start();
		 * 
		 * try { TimeUnit.SECONDS.sleep(2); } catch (InterruptedException e) {
		 * e.printStackTrace(); }
		 * 
		 * try { t.queue.transfer("test string"); } catch (InterruptedException
		 * e) { e.printStackTrace(); }
		 */

		new Thread(new Runnable() {

			@Override
			public void run() {
				try {
					t.queue.transfer("test string");
					// t.queue.add("test string");
					System.out.println("add ok");
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}).start();

		try {
			TimeUnit.SECONDS.sleep(2);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}

		new Thread(new Runnable() {
			@Override
			public void run() {
				try {
					System.out.println(Thread.currentThread().getName() + " thread begin ");
					System.out.println(Thread.currentThread().getName() + " - " + t.queue.take());
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}, "output thread").start();
	}
}

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.TimeUnit;

public class Test_08_SynchronusQueue {
	
	BlockingQueue<String> queue = new SynchronousQueue<>();
	
	public static void main(String[] args) {
		final Test_08_SynchronusQueue t = new Test_08_SynchronusQueue();
		
		new Thread(new Runnable() {
			@Override
			public void run() {
				try {
					System.out.println(Thread.currentThread().getName() + " thread begin " );
					try {
						TimeUnit.SECONDS.sleep(2);
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
					System.out.println(Thread.currentThread().getName() + " - " + t.queue.take());
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}, "output thread").start();
		
		/*try {
			TimeUnit.SECONDS.sleep(3);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}*/
		// t.queue.add("test add");
		try {
			t.queue.put("test put");
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		
		System.out.println(Thread.currentThread().getName() + " queue size : " + t.queue.size());
	}

}