First, demand :
-
Complete multi-user network sign-on function
-
User name password, server login prompt success or failure
Second, the analysis:
- Implementation uses Socket network programming based on TCP protocol
- TCP protocol based on the request - response pattern
- In network communication, first initiates communication program is called the client (Client) Program
- The first notification procedure is referred to wait for a connection server (Server) Program
- Use for data transmission stream IO
Third, the server
Thinking
1, designated port, used to create ServerSocket server;
2, blocking waits for a connection (Accept () method);
3, obtaining stream data I / O and analyzed;
4, release of resources;
Code:
The specific operation encapsulated inside a class, when there is a client connected to the server you can create a child thread to achieve its function;
public class TCPServer {
public static void main(String[] args) throws IOException {
// 1、指定端口，使用ServerSocket创建服务器
ServerSocket serverSocket = new ServerSocket(8888);
// 2、阻塞式等待连接 accept
boolean flag = true;
while (flag) {
Socket socket = serverSocket.accept();
System.out.println("有一个客户端连接了服务器");
new Thread(new Channel(socket)).start();
}
serverSocket.close();
}
static class Channel implements Runnable{
private Socket socket;
DataInputStream dis; //输入流
DataOutputStream dos; //输出流
public Channel(Socket socket) {
this.socket = socket;
try {
dis = new DataInputStream(this.socket.getInputStream());
dos = new DataOutputStream(this.socket.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
release();
}
}
@Override
public void run() {
System.out.println("客户端连接成功");
// 3、操作：输入输出流
String uName = "";
String uPwd = "";
//分析数据
String[] dataArray = receive().split("&");
for (String info : dataArray) {
String[] userInfo = info.split("=");
if (userInfo[0].equals("userName")) {
System.out.println("你的用户名为：" + userInfo[1]);
uName = userInfo[1];
} else {
System.out.println("你的密码为：" + userInfo[1]);
uPwd = userInfo[1];
}
}
//输出
if (uName.equals("daria") && uPwd.equals("123")) {
send("登录成功");
} else {
send("用户名或密码错误，请重新输入");
}
release();
}
//接收数据
private String receive() {
String datas = "";
try {
datas = dis.readUTF();
} catch (IOException e) {
e.printStackTrace();
}
return datas;
}
private void send(String msg) {
try {
dos.writeUTF(msg);
dos.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
//释放资源
private void release() {
try {
if (null != dos) {
dos.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if (null != dis) {
dis.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if (null != socket) {
socket.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Fourth, the client
Ideas:
1. Create the Socket connection is established the client and server address + port;
2, data transmission or a data reception response through the I / O server flow;
3, end request, release of resources;
Code:
The transmitting and receiving data encapsulated into a respective internal class, easy maintenance;
public class TCPClient {
static class Send { //发送消息
private DataOutputStream dos;
private Socket socket;
private Scanner scanner;
private String msg;
public Send(Socket socket) {
this.scanner = new Scanner(System.in);
this.msg = this.init();
this.socket = socket;
try {
dos = new DataOutputStream(this.socket.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
private void send() {
try {
dos.writeUTF(this.msg);
dos.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
private String init() {
System.out.println("请输入用户名");
String userName = this.scanner.nextLine();
System.out.println("请输入密码");
String userPwd = this.scanner.nextLine();
return "userName=" + userName + "&" + "userPwd=" + userPwd;
}
}
static class Receive { //接收消息
private DataInputStream dis;
Socket socket;
public Receive(Socket socket) {
this.socket = socket;
try {
dis = new DataInputStream(this.socket.getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
public void receive() {
String result = null;
try {
result = dis.readUTF();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(result);
}
}
public static void main(String[] args) throws IOException {
// 1、建立连接 使用Socket创建客户端+服务器地址和端口
Socket socket = new Socket("127.0.0.1",8888);
// 2、操作：输入输出流
new Send(socket).send();
new Receive(socket).receive();
// 3、释放资源
socket.close();
}
}
Five test
Because there is no connection to the database is unable to determine the user name with the correct password, so here we specified a user name and password daria 123 to verify the information input;
