《How Tomcat Works》第一章：简单的Web容器

TomCat是常用的Web容器，我也使用了快一年了，但是平时出错的时候总是摸不着头脑，错误日志看不懂就抓瞎，所以这次看借着这本经典的书来看一看Tomcat的源码，希望能有所进步。
第一章是搭建一个简单的Web Server

public class HttpServer {

    ...
    public static void main(String[] args) {
        HttpServer server = new HttpServer();
        //等待被调用
        server.await();
    }

    public void await() {
        ServerSocket serverSocket = null;
        int port = 8080;
        try {
            //在本机创建一个套接字
            serverSocket = new ServerSocket(port, 1, InetAddress
                    .getByName("127.0.0.1"));
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }
        // Loop waiting for a request
        while (!shutdown) {
            Socket socket = null;
            InputStream input = null;
            OutputStream output = null;

            try {
                //Listens for a connection to be made to this socket and accepts it. The method blocks until a connection is made.
                socket = serverSocket.accept();
                input = socket.getInputStream();
                output = socket.getOutputStream();
                // create Request object and parse
                Request request = new Request(input);
                request.parse();

                // create Response object
                Response response = new Response(output);
                response.setRequest(request);
                response.sendStaticResource();

                // Close the socket
                socket.close();
                // check if the previous URI is a shutdown command
                shutdown = request.getUri().equals(SHUTDOWN_COMMAND);
            } catch (Exception e) {
                e.printStackTrace();
                continue;
            }
        }
    }
}

1. 首先在本机创建套接字，并等待request(用accepte函数)
2. 然后获取InputStream与OutputStream
3. 用inputstream构造request，然后调用它的prase函数，获取uri

4. 用outputstream构造response，调用其sendStaticResource函数，将uri指向的资源获取到，并读取之

   这就是一个简单的Web Server的工作流程。