NIO系列-02-升级版BIO

Mar 15, 2017 | NIO

声明

该系列文章由书籍《Netty权威指南》第二版整理而来。只为记录学习笔记。
若认为内容侵权请及时通知本人删除相关内容。

[TOC]

时间服务器–升级版(线程池)的BIO

服务端代码

服务端主程序

public class TimeServer {
	public static void main(String[] args) {
		int port = 1234;
		ServerSocket server = null;
		try {
			server = new ServerSocket(port);
			System.out.println("The time server is listening in port : " + port);
			Socket socket = null;
			// 线程池
			ClientHandlerPool singleExecutor = new ClientHandlerPool(50, 10000);
			while (true) {
				socket = server.accept();
				singleExecutor.execute(new TimeServerHandler(socket));
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (server != null) {
				try {
					server.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
}

服务端线程池

public class ClientHandlerPool {
	private ExecutorService executor;
	public ClientHandlerPool(int maxPoolSize, int queueSize) {
		executor = new ThreadPoolExecutor(Runtime.getRuntime().availableProcessors(), maxPoolSize, 120L,
				TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(queueSize));
	}
	public void execute(Runnable task) {
		executor.execute(task);
	}
}

服务端处理器类

public class TimeServerHandler implements Runnable {
	private Socket socket;
	private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
	public TimeServerHandler(Socket socket) {
		this.socket = socket;
	}
	@Override
	public void run() {
		BufferedReader in = null;
		PrintWriter out = null;
		try {
			in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
			out = new PrintWriter(this.socket.getOutputStream(), true);
			String body = null;
			while (true) {
				body = in.readLine();
				if (body == null)
					break;
				out.println(this.sdf.format(new Date()));
			}
		} catch (Exception e) {
			if (in != null) {
				try {
					in.close();
				} catch (IOException e1) {
					e1.printStackTrace();
				}
			}
			if (out != null) {
				out.close();
				out = null;
			}
			if (this.socket != null) {
				try {
					this.socket.close();
				} catch (IOException e1) {
					e1.printStackTrace();
				}
			}
		}
	}
}

客户端代码

客户端代码和上一篇文章“传统BIO”一致。

总结

这种升级版BIO模型有如下特点:

服务端资源开销可控
当服务端队列积满后，新的连接必须排队
可能导致所有的新的连接都超时

参考资料: 《Netty权威指南》第二版

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