EventListener 接口
让我们继续看SocketConnector中的acceptConnect方法:
@Override
protected void acceptConnect() throws ConnectorException {
new Thread(() -> {
while (true && started) {
Socket socket = null;
try {
socket = serverSocket.accept();
LOGGER.info("新增连接:" + socket.getInetAddress() + ":" + socket.getPort());
} catch (IOException e) {
//单个Socket异常,不要影响整个Connector
LOGGER.error(e.getMessage(), e);
} finally {
IoUtils.closeQuietly(socket);
}
}
}).start();
}
注意socket = serverSocket.accept(),这里获取到socket之后只是打印日志,并没获取socket的输入输出进行操作。
操作socket的输入和输出是否应该在SocketConnector中?这时大师又说话了,Connector责任是啥,就是管理connect的啊,connect怎么使用,关它屁事。再看那个无限循环,像不像再等待事件来临啊,成功accept一个socket就是一个事件,对scoket的使用,其实就是事件响应嘛。
OK,让我们按照这个思路来重构一下,目的就是加入事件机制,并将对具体实现的依赖控制在那几个工厂类里面去。
新增接口EventListener接口进行事件监听
public interface EventListener<T> {
/**
* 事件发生时的回调方法
* @param event 事件对象
* @throws EventException 处理事件时异常都转换为该异常抛出
*/
void onEvent(T event) throws EventException;
}
为Socket事件实现一下,acceptConnect中打印日志的语句可以移动到这来
public class SocketEventListener implements EventListener<Socket> {
private static final Logger LOGGER = LoggerFactory.getLogger(SocketEventListener.class);
@Override
public void onEvent(Socket socket) throws EventException {
LOGGER.info("新增连接:" + socket.getInetAddress() + ":" + socket.getPort());
}
重构Connector,添加事件机制,注意whenAccept方法调用了eventListener
public class SocketConnector extends Connector<Socket> {
... ...
private final EventListener<Socket> eventListener;
public SocketConnector(int port, EventListener<Socket> eventListener) {
this.port = port;
this.eventListener = eventListener;
}
@Override
protected void acceptConnect() throws ConnectorException {
new Thread(() -> {
while (true && started) {
Socket socket = null;
try {
socket = serverSocket.accept();
whenAccept(socket);
} catch (Exception e) {
//单个Socket异常,不要影响整个Connector
LOGGER.error(e.getMessage(), e);
} finally {
IoUtils.closeQuietly(socket);
}
}
}).start();
}
@Override
protected void whenAccept(Socket socketConnect) throws ConnectorException {
eventListener.onEvent(socketConnect);
}
... ...
}
重构ServerFactory,添加对具体实现的依赖
public class ServerFactory {
public static Server getServer(ServerConfig serverConfig) {
List<Connector> connectorList = new ArrayList<>();
SocketEventListener socketEventListener = new SocketEventListener();
ConnectorFactory connectorFactory =
new SocketConnectorFactory(new SocketConnectorConfig(serverConfig.getPort()), socketEventListener);
connectorList.add(connectorFactory.getConnector());
return new SimpleServer(serverConfig, connectorList);
}
}
再运行所有单元测试,一切都OK。
现在让我们来操作socket,实现一个echo功能的server吧。
直接添加到SocketEventListener中
public class SocketEventListener implements EventListener<Socket> {
private static final Logger LOGGER = LoggerFactory.getLogger(SocketEventListener.class);
@Override
public void onEvent(Socket socket) throws EventException {
LOGGER.info("新增连接:" + socket.getInetAddress() + ":" + socket.getPort());
try {
echo(socket);
} catch (IOException e) {
throw new EventException(e);
}
}
private void echo(Socket socket) throws IOException {
InputStream inputstream = null;
OutputStream outputStream = null;
try {
inputstream = socket.getInputStream();
outputStream = socket.getOutputStream();
Scanner scanner = new Scanner(inputstream);
PrintWriter printWriter = new PrintWriter(outputStream);
printWriter.append("Server connected.Welcome to echo.\n");
printWriter.flush();
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
if (line.equals("stop")) {
printWriter.append("bye bye.\n");
printWriter.flush();
break;
} else {
printWriter.append(line);
printWriter.append("\n");
printWriter.flush();
}
}
} finally {
IoUtils.closeQuietly(inputstream);
IoUtils.closeQuietly(outputStream);
}
}
}
之前都是在单元测试里面启动Server的,这次需要启动Server后,用telnet去使用echo功能,所以再为Server编写一个启动类,在其main方法里面启动Server
public class BootStrap {
public static void main(String[] args) throws IOException {
ServerConfig serverConfig = new ServerConfig();
Server server = ServerFactory.getServer(serverConfig);
server.start();
}
}
服务器启动后,使用telnet进行验证,如下:
到现在为止,我们的服务器终于有了实际功能,下一步终于可以去实现请求静态资源的功能了。
完整代码:https://github.com/pkpk1234/BeggarServletContainer/tree/step4
分支step4