报错显示：
C:\Users\wenjrg\Desktop\2019.5.14>java ClickTest
Exception in thread "main" java.net.UnknownHostException: a
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323)
at java.net.InetAddress.getAllByName0(InetAddress.java:1276)
at java.net.InetAddress.getAllByName(InetAddress.java:1192)
at java.net.InetAddress.getAllByName(InetAddress.java:1126)
at java.net.InetAddress.getByName(InetAddress.java:1076)
at ClickTest.main(ClickTest.java:11)
用Socket实现简单账号密码登录
1. 实现客户端
1 import java.io.BufferedReader;
2 import java.io.IOException;
3 import java.io.InputStreamReader;
4 import java.io.PrintWriter;
5 import java.net.*;
6
7 public class ClickTest {
8 //模拟用户登录
9 public static void main(String[] args) throws IOException {
10 //创建socket对象
11 Socket s=new Socket(InetAddress.getByName("127.0.0.1"),8888);
12 //Socket s=new Socket("itheima",8888);
13 //获取用户名和密码
14 BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
15 System.out.println("请输入用户名：");
16 String username=br.readLine();
17 System.out.println("请输入密码：");
18 String password=br.readLine();
19 //获取输出流对象(换行)
20 PrintWriter out=new PrintWriter(s.getOutputStream(),true);
21 //写出数据
22 out.println(username);
23 out.println(password);
24 //获取输入流对象
25 BufferedReader serverBr=new BufferedReader(new InputStreamReader(s.getInputStream()));
26 //获取服务器返回的数据
27 String result=serverBr.readLine();
28 System.out.println(result);
29 //释放
30 s.close();
31
32 }
33
34 }
2.服务端
1 import java.io.BufferedReader;
2 import java.io.IOException;
3 import java.io.InputStreamReader;
4 import java.io.PrintWriter;
5 import java.net.ServerSocket;
6 import java.net.Socket;
7
8 public class ServerTest {
9
10 public static void main(String[] args) throws IOException {
11 //创建服务器端socket对象
12 ServerSocket ss=new ServerSocket(8888);
13 //监听
14 Socket s=ss.accept();
15 //获取输入流对象
16 BufferedReader br=new BufferedReader(new InputStreamReader(s.getInputStream()));
17 //判断用户名和密码是否正确
18 String username=br.readLine();
19 String password=br.readLine();
20 //返回判断信息
21 boolean flag=false;
22 if("a".equals(username)&&"1234".equals(password)){
23 flag=true;
24 }
25 PrintWriter out=new PrintWriter(s.getOutputStream(),true);
26
27 if(flag){
28 out.println("登陆成功");
29 }else{
30 out.println("登录失败");
31 }
32 //释放资源
33 s.close();
34 //ss.close() 服务器不关闭
35
36 }
37
38 }
