Java_24网络编程---④模拟用户登录案例

案例代码1

需求：

客户端:
1.提示用户输入用户名和密码,将用户输入的用户名和密码发送给服务端
2.接收服务端验证完用户名和密码的结果
  服务端:
1.接收客户端发送过来的用户名和密码
           2.如果用户名不是itheima或者 密码不是123456,就向客户端写入”登录失败”
             否则向客户端写入登录成功

ClientTest.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

/*
 * 模拟用户登录
 */
public class ClientTest {
	public static void main(String[] args) throws  IOException  {
		//创建客户端Socket对象
		//Socket s = new Socket(InetAddress.getByName("itheima"),8888);
		Socket s = new Socket("itheima",8888);//Socket中的一个构造方法，将传进的主机名字符串，从而调用(InetAddress.getByName("itheima")获取所在的IP地址
		
		//获取用户名和密码
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		System.out.println("请输入用户名:");
		String username = br.readLine();
		System.out.println("请输入密码:");
		String password = br.readLine();
		
		
		//获取输出流对象
		//BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
		PrintWriter out = new PrintWriter(s.getOutputStream(),true);
		//写出数据
		out.println(username);
		out.println(password);
		
		//获取输入流对象
		BufferedReader serverBr = new BufferedReader(new InputStreamReader(s.getInputStream()));
		//获取服务器返回的数据
		String result = serverBr.readLine();
		System.out.println(result);
		//释放资源
		s.close();
	}
}

ServerTest.java

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

public class ServerTest {
	public static void main(String[] args) throws IOException {
		//创建服务器端Socket对象
		ServerSocket ss = new ServerSocket(8888);
		//监听
		Socket s = ss.accept();//获取客户端传来的数据对象
		//获取输入流对象
		BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
		//获取用户名和密码
		String username = br.readLine();
		String password = br.readLine();
		//判断用户名和密码是否正确
		boolean flag = false;
		if("itheima".equals(username) && "123456".equals(password)) {
			flag = true;
		}
		//获取输出流对象
		PrintWriter out = new PrintWriter(s.getOutputStream(),true);
		
		//返回判断信息
		if(flag) {
			out.println("登陆成功");
		}
		else {
			out.println("登陆失败");
		}
		//释放资源
		s.close();
		//ss.close();//服务器一般不关闭
	}
}

案例代码2

对案例代码1进行改写
需求：

将用户名和密码封装到一个User类中,提供对应的构造方法和getter/setter方法
新建一个UserDB类里面定义一个集合,在集合中添加以下User对象
new User("zhangsan","123456");
		 new User("lisi","654321");
		 new User("itheima","itheima");
		 new User("admin","password");
 客户端:
1.提示用户输入用户名和密码,将用户输入的用户名和密码发送给服务端
2.接收服务端验证完用户名和密码的结果

 服务端:
1.服务端将客户端发送过来的用户名密码封装成User对象
2.集合中如果包括这个User对象,想客户端写入” 登录成功”
否则向客户端写入”登录失败”

ClientTest.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

/*
 * 模拟用户登录改写（面向对象版本）
 */
public class ClientTest {
	public static void main(String[] args) throws  IOException  {
		//创建客户端Socket对象
		Socket s = new Socket("itheima",8888);
		
		//获取用户名和密码
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		System.out.println("请输入用户名:");
		String username = br.readLine();
		System.out.println("请输入密码:");
		String password = br.readLine();
		
		
		//获取输出流对象
		PrintWriter out = new PrintWriter(s.getOutputStream(),true);
		//写出数据
		out.println(username);
		out.println(password);
		
		//获取输入流对象
		BufferedReader serverBr = new BufferedReader(new InputStreamReader(s.getInputStream()));
		//获取服务器返回的数据
		String result = serverBr.readLine();
		System.out.println(result);
		//释放资源
		s.close();
	}
}

ServerTest.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.List;

public class ServerTest {
	public static void main(String[] args) throws IOException {
		//创建服务器端Socket对象
		ServerSocket ss = new ServerSocket(8888);
		//监听
		Socket s = ss.accept();
		//获取输入流对象
		BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
		//获取用户名和密码
		String username = br.readLine();
		String password = br.readLine();
		//判断用户名和密码是否正确
		boolean flag = false;
	
		/*if("itheima".equals(username) && "123456".equals(password)) {
			flag = true;
		}*/
		
		List<User> users = UserDB.getUsers();
		User user = new User(username,password);
		if(users.contains(user)) {
			//匹配成功
			flag = true;
		}
		
		
		//获取输出流对象
		PrintWriter out = new PrintWriter(s.getOutputStream(),true);
		
		//返回判断信息
		if(flag) {
			out.println("登陆成功");
		}
		else {
			out.println("登陆失败");
		}
		//释放资源
		s.close();
		//ss.close();//服务器一般不关闭
	}
}

User.java

public class User{
	private String username;
	private String password;
	public User(){
		super();
	}
	public User(String username,String password){
		super();
		this.username = username;
		this.password = password;
	}

	public String getUsername(){
		return username;
	}
	public void setUsername(){
		this.username= username;
	}
	public String getPassword(){
		return password;
	}
	public void setPassword(){
		this.password = password;
	}
	//重写equails，而contains方法中使用了equails方法。
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		User other = (User) obj;
		if(password !== null){
			if(other.password !== null)
			return false;
		}else if(!password.equal(other.password)))
		return false;
		if(username!== null){
			if(other.username!== null)
			return false;
		}else if(!username.equal(other.username)))
		return false;
	}
}

UsereDB.java

/*
	存储用户对象，相当于模拟数据库
*/
import java.util.ArrayList;
import java.util.List;

public class UserDao{
	private static List<User> users = new List<User>();

	static {
		users.add(new User("zhangsan","123456"));
		users.add(new User("lisi","12345"));
		users.add(new User("wagnwu","1234"));
		users.add(new User("itheima","itheima"));
	}
	public static List<User> getUsers(){
		return Users;
	} 
}