nio服务端：改进服务端java客户端python版本客户端：python客户端改进版（多线程执行）
注意：如果想把服务端程序放在自己的服务器上，要记得开放相应的端口，否则客户端会显示连接超时。socket的ip地址改为公网ip,
nio服务端：
/*** @Author* @Description 学习selector* @Date**/public class select {public void getSelector() throws IOException {//创建 SelectorSelector selector = Selector.open();//用open方法创建ServerSocketChannel channel = ServerSocketChannel.open();//获取通道channel.configureBlocking(false);//切换为非阻塞模式channel.bind(new InetSocketAddress(9999));channel.register(selector, SelectionKey.OP_ACCEPT);//注册通道到选择器上，第二个参数为指定的事件为”监听接收事件“//// * 读 : SelectionKey.OP_READ （1）//* 写 : SelectionKey.OP_WRITE （4）//* 连接 : SelectionKey.OP_CONNECT （8）//* 接收 : SelectionKey.OP_ACCEPT （16）//* 若注册时不止监听一个事件，则可以使用“位或”操作符连接。//轮询式的获取选择器上已经“准备就绪”的事件while (selector.select() > 0) {System.out.println("开始");//7. 获取当前选择器中所有注册的“选择键(已就绪的监听事件)”Iterator<SelectionKey> it = selector.selectedKeys().iterator();while (it.hasNext()) {//8. 获取准备“就绪”的是事件SelectionKey sk = it.next();//9. 判断具体是什么事件准备就绪if (sk.isAcceptable()) {//10. 若“接收就绪”，获取客户端连接SocketChannel sChannel = channel.accept();//11. 切换非阻塞模式sChannel.configureBlocking(false);//12. 将该通道注册到选择器上sChannel.register(selector, SelectionKey.OP_READ);} else if (sk.isReadable()) {//13. 获取当前选择器上“读就绪”状态的通道SocketChannel sChannel = (SocketChannel) sk.channel();//14. 读取数据ByteBuffer buf = ByteBuffer.allocate(1024);int len = 0;while ((len = sChannel.read(buf)) > 0) {buf.flip();System.out.println(new String(buf.array(), 0, len));buf.clear();}}//15. 取消选择键 SelectionKeyit.remove();}}}public static void main(String[] args) throws IOException {new select().getSelector();}}
改进服务端
加一个catch ioexception，防止因为客户端关闭连接导致服务端也异常终止
主要逻辑在读取数据的函数 readData(sk);中，其他部分跟上面一样
while (selector.select() > 0) {// System.out.println("开始：");//7. 获取当前选择器中所有注册的“选择键(已就绪的监听事件)”Iterator<SelectionKey> it = selector.selectedKeys().iterator();while (it.hasNext()) {//8. 获取准备“就绪”的是事件SelectionKey sk = it.next();//9. 判断具体是什么事件准备就绪if (sk.isAcceptable()) {// 10. 若“接收就绪”，获取客户端连接SocketChannel sChannel = channel.accept();//11. 切换非阻塞模式sChannel.configureBlocking(false);//12. 将该通道注册到选择器上sChannel.register(selector, SelectionKey.OP_READ);} else if (sk.isReadable()) {readData(sk);//15. 取消选择键 SelectionKey}it.remove();}}}//读取客户端消息private void readData (SelectionKey key){//取到关联的channleSocketChannel channel = null;try {//得到channelchannel = (SocketChannel) key.channel();//创建bufferByteBuffer buffer = ByteBuffer.allocate(1024);int count = channel.read(buffer);//根据count的值做处理if (count > 0) {//把缓存区的数据转成字符串String msg = new String(buffer.array());//输出该消息System.out.println("form 客户端: " + msg);//向其它的客户端转发消息(去掉自己), 专门写一个方法来处理// sendInfoToOtherClients(msg, channel);}else {System.out.println("no dara");}} catch (IOException e) {try {System.out.println(channel.getRemoteAddress() + " 离线了..");e.printStackTrace();//取消注册key.cancel();//关闭通道channel.close();} catch (IOException e2) {e2.printStackTrace();;}}}
这样的话会发现即使服务端发生io异常也仍然未终止程序，有新的客户端连接时还可以继续正常运行
java客户端
客户端模拟多线程发送socket数据：
/*** @Author* @Description 多线程bio读写数据* @Date**/public class mutiClient {public static void main(String[] args) throws InterruptedException {// 接下来模拟3个Client并发访问服务器int poolsize = 3;ExecutorService pool = Executors.newFixedThreadPool(poolsize);Collection< Callable<Object>> tasks =new ArrayList<>(10);final String clientname="clientThread";for (int i = 0; i < poolsize; i++) {final int n = i;// 若每一个Client都保持使用BIO方式发送数据到Server，并读取数据。tasks.add(new Callable() {@Overridepublic Object call() throws Exception {Socket socket = new Socket("127.0.0.1", 9999);final InputStream input = socket.getInputStream();final OutputStream out = socket.getOutputStream();final String clientname_n = clientname + "_" + n;// BIO读取数据线程new Thread(clientname_n + "_read") {@Overridepublic void run() {byte[] bs = new byte[1024];while (true) {try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}int len = 0;try {while ((len = input.read(bs)) != -1) {System.out.println("Clinet thread " + Thread.currentThread().getName() + " read: " + new String(bs, 0, len));}} catch (IOException e) {e.printStackTrace();}}}}.start();// BIO写数据线程new Thread(clientname_n + "_write") {@Overridepublic void run() {int a = 0;while (true) {try {Thread.sleep(100);} catch (InterruptedException e) {e.printStackTrace();}String str = Thread.currentThread().getName()+ " hello, " + a;try {out.write(str.getBytes());a++;} catch (IOException e) {e.printStackTrace();}}}}.start();return null;}});}pool.invokeAll(tasks);
运行服务端再运行客户端，j结果：
python版本客户端：
from socket import *host='localhost'port=9999bufsize=1024addr=(host,port)tcpClient=socket(AF_INET,SOCK_STREAM)tcpClient.connect(addr)while True:data=input('>')if not data:breaktcpClient.send(str.encode(data))data=tcpClient.recv(bufsize)if not data:continueprint(data)tcpClient.close()
结果：
python客户端改进版（多线程执行）
注意：写sleep是因为防止主线程结束了导致多线程没有执行而失效
def tcpcilent(threadName,port):host = 'localhost'bufsize = 1024port=9999addr = (host, port)tcpClient = socket(AF_INET, SOCK_STREAM)tcpClient.connect(addr)i =0#tcpClient.setblocking(0)while True:tcpClient.send(str.encode(threadName+"uiyuiyiu"+'\n'))time.sleep(1)if i>100:breaktcpClient.close()if __name__ == '__main__':try:_thread.start_new_thread(tcpcilent, ("thread1", 9999,))_thread.start_new_thread(tcpcilent, ("thread2", 9999,))except:print("无法启动线程")time.sleep(5)
服务端：
