package Chapter1;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class EchoServer {
    private ServerSocket server;
    private int port = 8000;
    Socket socket;

    public static void main(String[] args) throws IOException {
        /*
         * //返回本地主机ip地址 InetAddress addr=InetAddress.getLocalHost();
         * //返回代表"222.34.5.7"的IP地址 InetAddress
         * addr2=InetAddress.getByName("222.34.5.7");
         * //返回域名为"www.baidu.com"的ip地址 InetAddress
         * addr3=InetAddress.getByName("www.baidu.com");
         */
        new EchoServer().service();
    }

    /**
     * 服务器端程序一直监听端口，来接收客户端程序的连接请求。
     * 如接收到连接请求，accept()方法就返回一个Socket对象，此对象与客户端的Socket对象形成一条通信线路，建立连接
     */
    public EchoServer() throws IOException {
        server = new ServerSocket(port); // 1.创建ServerSocket对象，在构造方法中指定监听的端口
        System.out.println("服务器端程序启动，等待客户端程序访问");
        socket = server.accept(); // 2.调用ServerSocket对象的accept()方法，来监听端口，等待客户端程序的连接请求。
        System.out.println("service开始连接客户端 " + socket.getInetAddress() + "："
                + socket.getPort());
    }

    public void service() {

        try {
            BufferedReader br;
            br = getReader(socket);
            PrintWriter pw = getWriter(socket);
            String msg = null;
            msg = br.readLine();
            System.out.println("service接收到客户端数据：" + msg);
            if (msg != null) {
                if (msg.equals("bye")) {
                    pw.println("over");
                    System.out.println("客户端已发送\"bye\"，服务端返回\"over\"，将关闭服务端socket");
                    socket.close();
                } else {
                    pw.println("service返回响应\"" + msg + "\"");
                }
            } else{
                System.out.println("service 未得到客户端数据");
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        // finally {
        // if (socket != null)
        // try {
        // socket.close();
        // System.out.println("服务端socket已关闭");
        // } catch (IOException e) {
        // // TODO Auto-generated catch block
        // e.printStackTrace();
        // }
        // }
    }

    /*
     * Socket类提供了getInputStream()、getOutputStream()方法，分别返回输入流InputStream对象
     * 、输出流OutputStream对象， 向输出流写数据---向对方发送数据 从输入流读数据---接收来自对方的数据
     *
     * InputStream socketIn=socket.getInputStream(); BufferedReader br=new
     * BufferedReader(new InputStreamReader(socketIn));
     *
     * OutputStream socketOut=socket.getOutputStream();
     * //参数true表示每写一行，PrintWriter缓存就自动溢出，把数据写到目的地 PrintWriter pw=new
     * PrintWriter(socketOut,true);
     */

    private BufferedReader getReader(Socket socket) throws IOException {

        InputStream socketIn = socket.getInputStream();
        BufferedReader br = new BufferedReader(new InputStreamReader(socketIn));
        return br;
    }

    private PrintWriter getWriter(Socket socket) throws IOException {
        OutputStream socketOut = socket.getOutputStream();
        PrintWriter pw = new PrintWriter(socketOut, true);
        return pw;
    }

}

socket编程1-EchoServer