现在，通过前几篇的总结，我们对Java多线程已经有所了解了，但是它们都是一些Java并发程序设计基础的底层构建块。对于实际编程来说，我们应该尽可能的远离底层结构。使用那些由并发处理的专业人士实现的较高层次的结构要方便的多，安全的多。
|
方法 |
正常动作 |
特殊情况下动作 |
|
add |
添加一个元素 |
如果队列满，则抛出IllegalStateException异常 |
|
element |
返回队列的头元素 |
如果队列空，抛出NoSuchElementException异常 |
|
offer |
添加一个元素并返回true |
如果队列满，返回false |
|
peek |
返回队列的头元素 |
如果队列空，则返回null |
|
poll |
移出并返回队列的头元素 |
如果队列空，则返回null |
|
put |
添加一个元素 |
如果队列满，则阻塞 |
|
remove |
移出并返回头元素 |
如果队列空，则抛出NoSuchElementException异常 |
|
take |
移出并返回头元素 |
如果队列满，则阻塞 |
/**
* @author xzzhao
*/
public class FileEnumerationTask implements Runnable {
public static File DUMMY = new File("");
private final BlockingQueue<File> queue;
private final File startingDirectory;
public FileEnumerationTask(BlockingQueue<File> queue, File startingDirectory) {
super();
this.queue = queue;
this.startingDirectory = startingDirectory;
}
@Override
public void run() {
try {
enumerate(startingDirectory);
queue.put(DUMMY);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void enumerate(File directory) throws InterruptedException {
File[] files = directory.listFiles();
for (File file : files) {
if (file.isDirectory()) {
enumerate(directory);
} else {
queue.put(file);
}
}
}
}/**
* @author xzzhao
*/
public class SearchTask implements Runnable {
private final BlockingQueue<File> queue;
private final String keyword;
public SearchTask(BlockingQueue<File> queue, String keyword) {
super();
this.queue = queue;
this.keyword = keyword;
}
@Override
public void run() {
try {
boolean done = false;
while (!done) {
File file = queue.take();
if (file == FileEnumerationTask.DUMMY) {
queue.put(file);
done = true;
} else {
search(file);
}
}
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/**
* 根据关键字搜索
*
* @param file
* @throws FileNotFoundException
*/
public void search(File file) throws FileNotFoundException {
try (Scanner in = new Scanner(file)) {
int lineNumber = 0;
while (in.hasNextLine()) {
lineNumber++;
String line = in.nextLine();
if (line.contains(keyword)) {
System.out.println("路径:" + file.getPath() + " 行号:" + lineNumber + " 行:" + line);
}
}
}
}
}/**
* @author xzzhao
*/
public class BlockingQueueTest {
public static void main(String[] args) {
final int FILE_QUEUE_SIZE = 10;
final int SERCH_THREADS = 100;
Scanner in = new Scanner(System.in);
System.out.println("请输入根目录 :");
String directory = in.nextLine();
System.out.println("请输入关键字 :");
String keyword = in.nextLine();
BlockingQueue<File> queue = new ArrayBlockingQueue<>(FILE_QUEUE_SIZE);
FileEnumerationTask enumerator = new FileEnumerationTask(queue, new File(directory));
new Thread(enumerator).start();
for (int i = 0; i <= SERCH_THREADS; i++) {
new Thread(new SearchTask(queue, keyword)).start();
}
}
}
原文地址：http://blog.csdn.net/qq710262350/article/details/43454027
