使用Eclipse中提供的Refactor(重构)工具提取接口

最近用到网络编程方面的知识，在网上看到帖子 Java Nio的Socket服务端编写 ，想跑一下提供的代码，但是在 Eclipse 中创建了对应的类，把代码粘贴进去却发现少了一个接口 TCPProtocol 的定义。

代码如下：

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Date;

public class TCPProtocolImpl implements TCPProtocol {
	private int bufferSize;

	public TCPProtocolImpl(int bufferSize) {
		this.bufferSize = bufferSize;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.weixiao.network.TCPProtocol#handleAccept(java.nio.channels.
	 * SelectionKey)
	 */
	@Override
	public void handleAccept(SelectionKey key) throws IOException {
		SocketChannel clientChannel = ((ServerSocketChannel) key.channel()).accept();
		clientChannel.configureBlocking(false);
		clientChannel.register(key.selector(), SelectionKey.OP_READ, ByteBuffer.allocate(bufferSize));
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.weixiao.network.TCPProtocol#handleRead(java.nio.channels.
	 * SelectionKey)
	 */
	@Override
	public void handleRead(SelectionKey key) throws IOException {
		// 获得与客户端通信的信道
		SocketChannel clientChannel = (SocketChannel) key.channel();

		// 得到并清空缓冲区
		ByteBuffer buffer = (ByteBuffer) key.attachment();
		buffer.clear();

		// 读取信息获得读取的字节数
		long bytesRead = clientChannel.read(buffer);

		if (bytesRead == -1) {
			// 没有读取到内容的情况
			clientChannel.close();
		} else {
			// 将缓冲区准备为数据传出状态
			buffer.flip();

			// 将字节转化为为UTF-16的字符串
			String receivedString = Charset.forName("UTF-16").newDecoder().decode(buffer).toString();

			// 控制台打印出来
			System.out.println("接收到来自" + clientChannel.socket().getRemoteSocketAddress() + "的信息:" + receivedString);

			// 准备发送的文本
			String sendString = "你好,客户端. @" + new Date().toString() + "，已经收到你的信息" + receivedString;
			buffer = ByteBuffer.wrap(sendString.getBytes("UTF-16"));
			clientChannel.write(buffer);

			// 设置为下一次读取或是写入做准备
			key.interestOps(SelectionKey.OP_READ | SelectionKey.OP_WRITE);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.weixiao.network.TCPProtocol#handleWrite(java.nio.channels.
	 * SelectionKey)
	 */
	@Override
	public void handleWrite(SelectionKey key) throws IOException {
		// do nothing
	}
}

我们可以使用Eclipse中提供的Refactor(重构)工具提取接口，操作方法如下图：

单击鼠标右键》Refactor(重构)》Extract Interface(提取接口)

就会自动生成接口文件，代码如下：

import java.io.IOException;
import java.nio.channels.SelectionKey;

public interface TCPProtocol {

	void handleAccept(SelectionKey key) throws IOException;

	void handleRead(SelectionKey key) throws IOException;

	void handleWrite(SelectionKey key) throws IOException;

}