NIO服務端
public class NioServer {
/**
* 啓動
*/
public void start() throws IOException {
/**
* 1. 創建Selector
*/
Selector selector = Selector.open();
/**
* 2. 通過ServerSocketChannel創建channel通道
*/
ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
/**
* 3. 爲channel通道綁定監聽端口
*/
serverSocketChannel.bind(new InetSocketAddress(8000));
/**
* 4. **設置channel爲非阻塞模式**
*/
serverSocketChannel.configureBlocking(false);
/**
* 5. 將channel註冊到selector上，監聽連接事件
*/
serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
System.out.println("服務器啓動成功！");
/**
* 6. 循環等待新接入的連接
*/
for (;;) { // while(true) c for;;
/**
* TODO 獲取可用channel數量
*/
int readyChannels = selector.select();
/**
* TODO 爲什麼要這樣！！？
*/
if (readyChannels == 0) continue;
/**
* 獲取可用channel的集合
*/
Set<SelectionKey> selectionKeys = selector.selectedKeys();
Iterator iterator = selectionKeys.iterator();
while (iterator.hasNext()) {
/**
* selectionKey實例
*/
SelectionKey selectionKey = (SelectionKey) iterator.next();
/**
* **移除Set中的當前selectionKey**
*/
iterator.remove();
/**
* 7. 根據就緒狀態，調用對應方法處理業務邏輯
*/
/**
* 如果是 接入事件
*/
if (selectionKey.isAcceptable()) {
acceptHandler(serverSocketChannel, selector);
}
/**
* 如果是 可讀事件
*/
if (selectionKey.isReadable()) {
readHandler(selectionKey, selector);
}
}
}
}
/**
* 接入事件處理器
*/
private void acceptHandler(ServerSocketChannel serverSocketChannel,
Selector selector)
throws IOException {
/**
* 如果要是接入事件，創建socketChannel
*/
SocketChannel socketChannel = serverSocketChannel.accept();
/**
* 將socketChannel設置爲非阻塞工作模式
*/
socketChannel.configureBlocking(false);
/**
* 將channel註冊到selector上，監聽 可讀事件
*/
socketChannel.register(selector, SelectionKey.OP_READ);
/**
* 回覆客戶端提示信息
*/
socketChannel.write(Charset.forName("UTF-8")
.encode("你與聊天室裏其他人都不是朋友關係，請注意隱私安全"));
}
/**
* 可讀事件處理器
*/
private void readHandler(SelectionKey selectionKey, Selector selector)
throws IOException {
/**
* 要從 selectionKey 中獲取到已經就緒的channel
*/
SocketChannel socketChannel = (SocketChannel) selectionKey.channel();
/**
* 創建buffer
*/
ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
/**
* 循環讀取客戶端請求信息
*/
String request = "";
while (socketChannel.read(byteBuffer) > 0) {
/**
* 切換buffer爲讀模式
*/
byteBuffer.flip();
/**
* 讀取buffer中的內容
*/
request += Charset.forName("UTF-8").decode(byteBuffer);
}
/**
* 將channel再次註冊到selector上，監聽他的可讀事件
*/
socketChannel.register(selector, SelectionKey.OP_READ);
/**
* 將客戶端發送的請求信息 廣播給其他客戶端
*/
if (request.length() > 0) {
// 廣播給其他客戶端
broadCast(selector, socketChannel, request);
}
}
/**
* 廣播給其他客戶端
*/
private void broadCast(Selector selector,
SocketChannel sourceChannel, String request) {
/**
* 獲取到所有已接入的客戶端channel
*/
Set<SelectionKey> selectionKeySet = selector.keys();
/**
* 循環向所有channel廣播信息
*/
selectionKeySet.forEach(selectionKey -> {
Channel targetChannel = selectionKey.channel();
// 剔除發消息的客戶端
if (targetChannel instanceof SocketChannel
&& targetChannel != sourceChannel) {
try {
// 將信息發送到targetChannel客戶端
((SocketChannel) targetChannel).write(
Charset.forName("UTF-8").encode(request));
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
/**
* 主方法
* @param args
*/
public static void main(String[] args) throws IOException {
new NioServer().start();
}
}
NIO客戶端
public class NioClient {
/**
* 啓動
*/
public void start(String nickname) throws IOException {
/**
* 連接服務器端
*/
SocketChannel socketChannel = SocketChannel.open(
new InetSocketAddress("127.0.0.1", 8000));
/**
* 接收服務器端響應
*/
// 新開線程，專門負責來接收服務器端的響應數據
// selector ， socketChannel ， 註冊
Selector selector = Selector.open();
socketChannel.configureBlocking(false);
socketChannel.register(selector, SelectionKey.OP_READ);
new Thread(new NioClientHandler(selector)).start();
/**
* 向服務器端發送數據
*/
Scanner scanner = new Scanner(System.in);
while (scanner.hasNextLine()) {
String request = scanner.nextLine();
if (request != null && request.length() > 0) {
socketChannel.write(
Charset.forName("UTF-8")
.encode(nickname + " : " + request));
}
}
}
public static void main(String[] args) throws IOException {
// new NioClient().start();
}
}
客戶端線程，處理服務器端響應的的消息
public class NioClientHandler implements Runnable {
private Selector selector;
public NioClientHandler(Selector selector) {
this.selector = selector;
}
@Override
public void run() {
try {
for (;;) {
int readyChannels = selector.select();
if (readyChannels == 0) continue;
/**
* 獲取可用channel的集合
*/
Set<SelectionKey> selectionKeys = selector.selectedKeys();
Iterator iterator = selectionKeys.iterator();
while (iterator.hasNext()) {
/**
* selectionKey實例
*/
SelectionKey selectionKey = (SelectionKey) iterator.next();
/**
* **移除Set中的當前selectionKey**
*/
iterator.remove();
/**
* 7. 根據就緒狀態，調用對應方法處理業務邏輯
*/
/**
* 如果是 可讀事件
*/
if (selectionKey.isReadable()) {
readHandler(selectionKey, selector);
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 可讀事件處理器
*/
private void readHandler(SelectionKey selectionKey, Selector selector)
throws IOException {
/**
* 要從 selectionKey 中獲取到已經就緒的channel
*/
SocketChannel socketChannel = (SocketChannel) selectionKey.channel();
/**
* 創建buffer
*/
ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
/**
* 循環讀取服務器端響應信息
*/
String response = "";
while (socketChannel.read(byteBuffer) > 0) {
/**
* 切換buffer爲讀模式
*/
byteBuffer.flip();
/**
* 讀取buffer中的內容
*/
response += Charset.forName("UTF-8").decode(byteBuffer);
}
/**
* 將channel再次註冊到selector上，監聽他的可讀事件
*/
socketChannel.register(selector, SelectionKey.OP_READ);
/**
* 將服務器端響應信息打印到本地
*/
if (response.length() > 0) {
System.out.println(response);
}
}
}
我們定義三個客戶端，模擬三個用戶在聊天室發送消息
public class AClient {
public static void main(String[] args)
throws IOException {
new NioClient().start("AClient");
}
}
public class BClient {
public static void main(String[] args)
throws IOException {
new NioClient().start("BClient");
}
}
public class CClient {
public static void main(String[] args)
throws IOException {
new NioClient().start("CClient");
}
}