工厂设计模式是Java中最常用的设计模式之一。它是一种创建型设计模式,能够用于创建一个或多个类所需要的对象。有了这个工厂,我们就能集中的创建对象。
集中创建方式给我们带来了一些好处,例如:
1. 能够很容易的改变类创建的对象或者创建对象的方式;
2. 能够很容易限制对象的创建,例如:我们只能为a类创建N个对象;
3. 能够很容易的生成有关对象创建的统计数据。
在Java中,我们通常使用两种方式来创建线程:继承Thread类和实现Runnable接口。Java还提供了一个接口,既ThreadFactory接口,用于创建你自己的线程对象工厂。
很多类中,例如:ThreadPoolExecutor,使用构造函数来接收ThreadFactory来作为参数。这个工厂参数将会在程序执行时创建新的线程。使用ThreadFactory,你能够自定义执行程序如何创建线程,例如为线程定义适当的名称、优先级,或者你甚至可以将它设定为守护线程。
ThreadFactory例子
在这个例子中,我们将学习如何通过实现一个ThreadFactory接口来创建一个有个性化名称的线程对象,同时,我们保存了线程对象的创建信息。
Task.java
class Task implements Runnable { @Override public void run() { try { TimeUnit.SECONDS.sleep(2); } catch (InterruptedException e) { e.printStackTrace(); } } }
CustomThreadFactory.java
<span style="font-size:18px;">public class CustomThreadFactory implements ThreadFactory { private int counter; private String name; private List<String> stats; public CustomThreadFactory(String name) { counter = 1; this.name = name; stats = new ArrayList<String>(); } @Override public Thread newThread(Runnable runnable) { Thread t = new Thread(runnable, name + "-Thread_" + counter); counter++; stats.add(String.format("Created thread %d with name %s on %s \n", t.getId(), t.getName(), new Date())); return t; } public String getStats() { StringBuffer buffer = new StringBuffer(); Iterator<String> it = stats.iterator(); while (it.hasNext()) { buffer.append(it.next()); } return buffer.toString(); } }</span>
<span style="font-size:18px;">public static void main(String[] args) { CustomThreadFactory factory = new CustomThreadFactory("CustomThreadFactory"); Task task = new Task(); Thread thread; System.out.printf("Starting the Threads\n\n"); for (int i = 1; i <= 10; i++) { thread = factory.newThread(task); thread.start(); } System.out.printf("All Threads are created now\n\n"); System.out.printf("Give me CustomThreadFactory stats:\n\n" + factory.getStats()); }</span>
<span style="font-size:18px;">Output : Starting the Threads All Threads are created now Give me CustomThreadFactory stats: Created thread 9 with name CustomThreadFactory-Thread_1 on Tue Jan 06 13:18:04 IST 2015 Created thread 10 with name CustomThreadFactory-Thread_2 on Tue Jan 06 13:18:04 IST 2015 Created thread 11 with name CustomThreadFactory-Thread_3 on Tue Jan 06 13:18:04 IST 2015 Created thread 12 with name CustomThreadFactory-Thread_4 on Tue Jan 06 13:18:04 IST 2015 Created thread 13 with name CustomThreadFactory-Thread_5 on Tue Jan 06 13:18:04 IST 2015 Created thread 14 with name CustomThreadFactory-Thread_6 on Tue Jan 06 13:18:04 IST 2015 Created thread 15 with name CustomThreadFactory-Thread_7 on Tue Jan 06 13:18:04 IST 2015 Created thread 16 with name CustomThreadFactory-Thread_8 on Tue Jan 06 13:18:04 IST 2015 Created thread 17 with name CustomThreadFactory-Thread_9 on Tue Jan 06 13:18:04 IST 2015 Created thread 18 with name CustomThreadFactory-Thread_10 on Tue Jan 06 13:18:04 IST 2015</span>
Happy Learning !!
原文连接:Creating Threads Using java.util.concurrent.ThreadFactory
使用java.util.concurrent.ThreadFactory类创建线程
原文地址:http://blog.csdn.net/rlanffy/article/details/42474853