轻量级任务队列

public abstract class TaskQueue<T> {    private Thread execThread;    private List<T> queue = new LinkedList<T>();    public void addTask(T task) {        queue.add(task);        if (null == execThread || !execThread.isAlive())            loop();    }        public void addALLTask(List<T> tasks) {    queue.addAll(tasks);    if (null == execThread || !execThread.isAlive())            loop();    }    protected void loop() {        (execThread = new Thread() {            @Override            public void run() {                while (!queue.isEmpty()) {                    if (isOk(queue.get(0)))                        execute(queue.remove(0));                    else                    queue.add(queue.remove(0));                }            }        }).start();    }    protected abstract void execute(T task);    public void stop(){        queue.clear();    }        public void interrupt(){    execThread.interrupt();    }        protected boolean isOk(T task){    return true;    }}

使用示例：

public class TaskQueueTest {private TaskQueue<String> queue = new TaskQueueExample();private static String[] tasks = { "a", "b", "c", "d" };private Map<String, String> resources = new HashMap<>();public static void main(String[] args) {final TaskQueueTest test = new TaskQueueTest();for (String t : tasks)test.queue.addTask(t);new Thread() {String[] ks = new String[tasks.length];int p = 0;@Overridepublic void run() {while (check()) {double random = Math.random();String key = null;if(p != 0)key = ks[((int) (random * 1000)) % p];//保证只取ks的前p个元素elsekey = ks[0];test.resources.put(key, random + "");}}public boolean check() {boolean b = false;int i;for (i = -1,p = 0; p < tasks.length; p++) {if (!test.resources.containsKey(tasks[p])) {//i=i+1;ks[++i] = tasks[p];b = true;}}p = i;return b;}}.start();}class TaskQueueExample extends TaskQueue<String> {@Overrideprotected void execute(String task) {System.out.println("task: " + task + " resource:" + resources.get(task));}@Overrideprotected boolean isOk(String task) {return resources.containsKey(task);}}}