phaser，开启三个线程分别搜索三个文件夹

Phaser表示“阶段器”，用来解决控制多个线程分阶段共同完成任务的情景问题

启动三个线程，分别对三个文件夹搜索，文件要以txt结尾，修改时间要在一天之内，并将文件路径打印在控制台

  

/**
 * 开启三个线程对三个文件夹进行搜索
 *
 */
public class FileSearch  implements Runnable {
    private String path;// 查找路径
    private String suffix;// 文件后缀
    private List<String> result;// 结果集
    private Phaser phaser;

    public FileSearch(String path, String end, Phaser phaser) {
        this.path = path;
        this.suffix = end;
        this.phaser = phaser;
        this.result = new ArrayList<String>();
    }

    private void directoryProcess(File file) {
        File list[] = file.listFiles();
        if (list != null) {
            for (File file2 : list) {
                if (file2.isDirectory()) {
                    directoryProcess(file2);
                } else {
                    fileProcess(file2);
                }
            }
        }
    }

    private void fileProcess(File file) {
        if (file.getName().endsWith(suffix)) {
            result.add(file.getAbsolutePath());
        }
    }

    //只保留最近一天有过更改的文件
    private void filterResultLatest() {
        List<String> newResult = new ArrayList<String>();
        long actualDate = new Date().getTime();
        for (int i = 0; i < result.size(); i++) {
            File file = new File(result.get(i));
            long lastModifyTime = file.lastModified();
            if (actualDate - lastModifyTime < TimeUnit.MICROSECONDS.convert(1,
                    TimeUnit.DAYS)) {
                newResult.add(result.get(i));
            }
        }
        result = newResult;
    }

    private boolean firstCheckResults() {
        if (result.isEmpty()) {
            System.out.println(Thread.currentThread().getName() + " 搜索完成    Phase =  "
                    + phaser.getPhase() + "  ,  result = 0 , 取消注册");
            phaser.arriveAndDeregister();
            return false;
        } else {
            System.out.println(Thread.currentThread().getName() + " 搜索完成    Phase =  "
                    + phaser.getPhase() + "  ,   result = " + result.size());
            phaser.arriveAndAwaitAdvance();
            return true;
        }
    }

    private boolean  secondCheckResults() {
        if (result.isEmpty()) {
            System.out.println(Thread.currentThread().getName() + " 经过对修改时间过滤后    Phase =  "
                    + phaser.getPhase() + " ,  result = 0 , 取消注册");
            phaser.arriveAndDeregister();
            return false;
        } else {
            System.out.println(Thread.currentThread().getName() + "  经过对修改时间过滤后     Phase =  "
                    + phaser.getPhase() + "  ,   result = " + result.size());
            phaser.arriveAndAwaitAdvance();
            return true;
        }
    }
    
    private void showInfo() {
        for (int i = 0; i < result.size(); i++) {
            System.out.println(Thread.currentThread().getName() + ":"
                    + result.get(i));
        }
        phaser.arriveAndAwaitAdvance();
    }

    @Override
    public void run() {
        phaser.arriveAndAwaitAdvance();
        System.out.println(Thread.currentThread().getName()+": starts");
        File file=new File(path);
        //将满足后缀结尾的文件的绝对路径放到results中
        if(file.isDirectory()){
            directoryProcess(file);
        }

        //第一次检查，假如result为空，当前线程从phaser中注销
        if(!firstCheckResults()){
            return;
        }
       //对搜索的结果过滤，只保留在最近一天修改过的文件
        filterResultLatest();

        //有可能在上一步中，本来有10个文件，但是更改时间都是超过一天的，经过上一步后，result为空了
        if(!secondCheckResults()){
            return;
        }
        //打印文件列表
        showInfo();
        //取消注册
        phaser.arriveAndDeregister();
    }

        public static void main(String[] args) {
            Phaser phaser = new Phaser(3);
            Thread t1 = new Thread(new FileSearch("C:\Users\PHP\Desktop\abc\a", "txt", phaser), "【线程一】");
            t1.start();
            Thread t2 = new Thread(new FileSearch("C:\Users\PHP\Desktop\abc\b", "txt", phaser), "【线程二】");
            t2.start();
            Thread t3 = new Thread(new FileSearch("C:\Users\PHP\Desktop\abc\c", "txt", phaser), "【线程三】");
            t3.start();
            try {
                t1.join();
                t2.join();
                t3.join();
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println("Terminated:" + phaser.isTerminated());
        }

}