NoHttp封装--06 NoHttp之队列、队列优先级

摘要：程序入口第一种，先进先出的队列第二种，没有顺序的队列往队列中添加请求请求是一个先进先出的队列如果方法不做比较返回，那么是无序的方法是一个阻塞的方法，每次调用会拿到队列中的第一个任务，如果队列为空，这个方法将一直阻塞，知道队列中有任务再次返回

public class Main {

    /**
     * 程序入口
     */
    public void start() {
        // 第一种，先进先出的队列
        // YolandaLinkedQueue queue = new YolandaLinkedQueue(3);
        // queue.start();
        // 第二种，没有顺序的队列
        YolandaQueue queue = new YolandaQueue(1);
        queue.start();
        // 往队列中添加请求
        for (int i = 0; i < 20; i++) {
            Request request = new Request("请求" + i);
            if (i == 10)
                request.setPriority(Priority.C);
            if (i == 15)
                request.setPriority(Priority.D);
            queue.add(request);
        }
    }

    public static void main(String[] args) {
        Main main = new Main();
        main.start();
    }

}

public class YolandaLinkedQueue {

    private BlockingQueue blockingQueue;

    private TaskExecutor[] taskExecutors;

    public YolandaLinkedQueue(int poolSize) {
        // LinkedBlockingQueue是一个先进先出的队列
        blockingQueue = new LinkedBlockingQueue<>();
        taskExecutors = new TaskExecutor[poolSize];
    }

    public void add(Request request) {
        blockingQueue.add(request);
    }

    public void start() {
        for (int i = 0; i < taskExecutors.length; i++) {
            taskExecutors[i] = new TaskExecutor(blockingQueue);
            taskExecutors[i].start();
        }
    }

    public void stop() {
        for (TaskExecutor taskExecutor : taskExecutors) {
            taskExecutor.setRunning(false);
            taskExecutor.interrupt();
        }
    }

}

public class YolandaQueue {

    private BlockingQueue blockingQueue;

    private TaskExecutor[] taskExecutors;

    private AtomicInteger atomicInteger = new AtomicInteger();

    public YolandaQueue(int poolSize) {
        // 如果Comparable#compareTo(Object)方法不做比较返回0，那么是无序的
        blockingQueue = new PriorityBlockingQueue();
        taskExecutors = new TaskExecutor[poolSize];
    }

    public void add(Request request) {
        request.setOrder(atomicInteger.incrementAndGet());
        blockingQueue.add(request);
    }

    public void start() {
        for (int i = 0; i < taskExecutors.length; i++) {
            taskExecutors[i] = new TaskExecutor(blockingQueue);
            taskExecutors[i].start();
        }
    }

    public void stop() {
        for (TaskExecutor taskExecutor : taskExecutors) {
            taskExecutor.setRunning(false);
            taskExecutor.interrupt();
        }
    }

}

public class TaskExecutor extends Thread {

    private BlockingQueue blockingQueue;

    private boolean isRunning = true;

    public TaskExecutor(BlockingQueue blockingQueue) {
        this.blockingQueue = blockingQueue;
    }

    /**
     * @param isRunning the isRunning to set
     */
    public void setRunning(boolean isRunning) {
        this.isRunning = isRunning;
    }

    @Override
    public void run() {
        while (isRunning) {
            Request request = null;
            try {
                // take方法是一个阻塞的方法，每次调用会拿到队列中的第一个任务，如果队列为空，这个方法将一直阻塞，知道队列中有任务再次返回
                request = blockingQueue.take();
            } catch (InterruptedException e) {
                return;
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(request.getName());
        }
    }

}

public class Request implements Comparable {

    private String name;

    private Priority mPriority = Priority.B;

    private int order;

    /**
     * @param name
     */
    public Request(String name) {
        super();
        this.name = name;
    }

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @param mPriority the mPriority to set
     */
    public void setPriority(Priority mPriority) {
        this.mPriority = mPriority;
    }

    /**
     * @return the mPriority
     */
    public Priority getPriority() {
        return mPriority;
    }

    /**
     * @return the order
     */
    public int getOrder() {
        return order;
    }

    /**
     * @param order the order to set
     */
    public void setOrder(int order) {
        this.order = order;
    }

    @Override
    public int compareTo(Request other) {
        // 返回正数代表1排在2后面，返回负数表示1排在2前面
        Priority priority = getPriority();// 拿到自身的优先级
        Priority otherPriority = other.getPriority();
        return priority == otherPriority ? getOrder() - other.getOrder() : otherPriority.ordinal() - priority.ordinal();
    }

}

public enum Priority {

    /**
     * 优先级最低
     */
    A,

    /**
     * 默认优先级
     */
    B,

    /**
     * 优先级最高
     */
    C,

    /**
     * 一般情况下不用；特殊情况下，请求假如到到队列后立即执行
     */
    D

}