网络编程

1: 测试IP

 1 package Net;
 2 
 3 import java.net.InetAddress;
 4 import java.net.UnknownHostException;
 5 
 6 /**
 7  * author liulei
 8  * data  5.26
 9  * since 1.8
10  * version 1.0
11  * Description  测试IP
12  */
13 public class Test1 {
14     public static void main(String[] args) throws UnknownHostException {
15         //查询本机地址
16         InetAddress inetAddress = InetAddress.getByName("127.0.0.1");
17         System.out.println(inetAddress);///127.0.0.1
18         InetAddress localhost = InetAddress.getByName("localhost");
19         System.out.println(localhost);//localhost/127.0.0.1
20         InetAddress localHost1 = InetAddress.getLocalHost();
21         System.out.println(localHost1);//DESKTOP-PAIHBK9/169.254.192.87
22         //查询网络ip地址
23         InetAddress byName = InetAddress.getByName("www.baidu.com");
24         System.out.println(byName);//域名+ip
25         //常用方法
26         System.out.println(byName.getHostName());//域名
27         System.out.println(byName.getHostAddress());//ip
28         System.out.println(byName.getCanonicalHostName());//规范的名字
29         System.out.println(byName.getAddress());//[B@7f31245a
30         System.out.println(byName.getClass());//inetadress对象
31     }
32 }

2：测试端口

 1 package Net;
 2 
 3 import java.net.InetSocketAddress;
 4 
 5 /**
 6  * author liulei
 7  * data   5.26
 8  * since 1.8
 9  * version 1.0
10  * Description    测试端口
11  */
12 public class Test2 {
13     public static void main(String[] args) {
14         InetSocketAddress inetSocketAddress = new InetSocketAddress("127.0.0.1",8080);
15         InetSocketAddress s = new InetSocketAddress("localhost",8080);
16         System.out.println(inetSocketAddress);
17         System.out.println(s);
18         System.out.println(inetSocketAddress.getAddress());
19         System.out.println(inetSocketAddress.getHostName());//ip
20         System.out.println(inetSocketAddress.getPort());//端口
21 
22 
23     }
24 }

3：TCP

使用TCP进行发送消息

 1 package Net;
 2 
 3 import java.io.IOException;
 4 import java.io.OutputStream;
 5 import java.net.InetAddress;
 6 import java.net.InetSocketAddress;
 7 import java.net.Socket;
 8 
 9 /**
10  * author liulei
11  * data  5.26
12  * since 1.8
13  * version 1.0
14  * Description  客户端
15  */
16 public class Test31 {
17     public static void main(String[] args) throws IOException {
18         //1要知道服务器端的端口号和ip
19         InetAddress serverIp = InetAddress.getByName("127.0.0.1");
20         int port = 9999;
21         //2创建一个socket连接
22         Socket socket = new Socket(serverIp,port);
23         OutputStream outputStream = socket.getOutputStream();
24         //发送消息IO流
25         outputStream.write("你好，欢迎学习狂神说java".getBytes());
26         outputStream.close();
27         socket.close();
28 
29     }
30 }

客户端

 1 package Net;
 2 
 3 import java.io.ByteArrayOutputStream;
 4 import java.io.IOException;
 5 import java.io.InputStream;
 6 import java.net.ServerSocket;
 7 import java.net.Socket;
 8 
 9 /**
10  * author liulei
11  * data  5.26
12  * since 1.8
13  * version 1.0
14  * Description  服务端
15  */
16 public class Test32 {
17     public static void main(String[] args) throws IOException {
18         ServerSocket serverSocket = null;
19         Socket socket = null;
20         InputStream inputStream = null;
21         ByteArrayOutputStream baos = null;
22 
23         try {
24             //先有一个地址
25             serverSocket = new ServerSocket(9999);
26             while (true){
27                 //等待客户端连过来
28                 socket = serverSocket.accept();
29                 //读取客户端的信息
30                 inputStream = socket.getInputStream();
31                 byte[] buffer = new byte[1024];
32                baos = new ByteArrayOutputStream();//管道流方法
33                 int len;
34                 while((len = inputStream.read(buffer))!=-1){
35                     //这种方法可能因为乱码出现错误
36                     //String str=new String(buffer,0,len);
37                     //System.out.println(str);
38                     baos.write(buffer,0,len);//使用管道流方法接受信息
39 
40                 }
41                 System.out.println(baos.toString());
42             }
43         }catch (Exception e){
44             e.printStackTrace();
45         }
46         finally {
47             if(baos != null){
48                 baos.close();
49             }
50             if(inputStream != null){
51                 inputStream.close();
52             }
53             if(socket != null){
54                 socket.close();
55             }
56             if(serverSocket != null){
57                 serverSocket.close();
58             }
59         }
60     }
61 }

服务器端

使用TCP进行文件的发送

 1 package Net;
 2 
 3 import java.io.*;
 4 import java.net.InetAddress;
 5 import java.net.Socket;
 6 
 7 /**
 8  * author liulei
 9  * data
10  * since 1.8
11  * version 1.0
12  * Description  TCp客户端进行发送图片
13  */
14 public class Test41 {
15     public static void main(String[] args) throws Exception{
16         //创建一个socket连接
17         Socket socket = new Socket(InetAddress.getByName("127.0.0.1"),9999);
18         //创建一个输出流
19         OutputStream os = socket.getOutputStream();
20         //读取文件
21         FileInputStream fis = new FileInputStream(new File("a.png"));
22         byte[] buffer = new byte[1024];
23         int len;
24         while ((len  = fis.read(buffer))!=-1){
25             os.write(buffer,0,len);
26         }
27         socket.shutdownOutput();//通知服务器我已经发送完毕，不需要继续监听堵塞了
28         //确定服务器接受完毕才可以断开连接
29         InputStream stream = socket.getInputStream();
30         byte[] buffer1 = new byte[1024];
31         ByteArrayOutputStream baos = new ByteArrayOutputStream();
32         int len1;
33         while ((len1 = stream.read(buffer1))!=-1){
34             baos.write(buffer1,0,len1);
35         }
36         System.out.println(baos.toString());
37         //关闭资源
38         baos.close();
39         fis.close();
40         os.close();
41         socket.close();
42     }
43 }

TCp客户端进行发送图片

 1 package Net;
 2 
 3 import java.io.*;
 4 import java.net.ServerSocket;
 5 import java.net.Socket;
 6 
 7 /**
 8  * author liulei
 9  * data
10  * since 1.8
11  * version 1.0
12  * Description tcp文件上传服务端
13  */
14 public class Test42 {
15     public static void main(String[] args) throws IOException {
16         //先指明自己的端口号
17         ServerSocket serverSocket = new ServerSocket(9999);
18         Socket accept = serverSocket.accept();//获取一个socket对象
19         InputStream inputStream = accept.getInputStream();//输入流对象
20         FileOutputStream fos = new FileOutputStream(new File("b.jpg"));//文件输出流，把文件输出到本地
21         byte[] buffer = new byte[1024];
22         int len;
23         while ((len = inputStream.read(buffer))!=-1){
24             fos.write(buffer,0,len);
25         }
26         //通知客户端接受完毕
27         OutputStream os = accept.getOutputStream();
28         os.write("我读到了你的信息,你可以断开了".getBytes());
29         //关闭资源
30         os.close();
31         fos.close();
32         inputStream.close();
33         serverSocket.close();
34     }
35 }

tcp文件上传服务端

4：UDP

 1 package Net;
 2 
 3 import java.io.IOException;
 4 import java.net.*;
 5 
 6 /**
 7  * author liulei
 8  * data   5.27
 9  * since 1.8
10  * version 1.0
11  * Description  udp客户端（简单udp通信的例子）
12  */
13 public class Test51 {//不需要连接服务器
14     public static void main(String[] args) throws IOException {
15         //建立一个socket
16         DatagramSocket socket = new DatagramSocket(8888);
17         //建个包
18         String msg = "111你好啊11111";
19         InetAddress localhost = InetAddress.getByName("localhost");
20         int port = 9090;
21         //数据，数据的长度，数据发给谁
22         DatagramPacket packet = new DatagramPacket(msg.getBytes(),0,msg.length(),localhost,port);
23         //发送包，
24         socket.send(packet);
25         //关闭流
26         socket.close();
27     }
28 }

udp客户端（简单udp通信的例子）

 1 package Net;
 2 
 3 
 4 
 5 import java.net.DatagramPacket;
 6 import java.net.DatagramSocket;
 7 
 8 /**
 9  * author liulei
10  * data   5.27
11  * since 1.8
12  * version 1.0
13  * Description  udp服务器端（简单udp通信的例子）
14  */
15 public class Test52 {
16     public static void main(String[] args) throws  Exception{
17         //开放端口
18         DatagramSocket socket = new DatagramSocket(9090);
19         //接受数据包
20         byte[] buffer = new byte[1024];
21         DatagramPacket packet = new DatagramPacket(buffer,0,buffer.length);
22         socket.receive(packet);//堵塞接受
23         System.out.println(packet.getAddress().getHostAddress());
24         System.out.println(new String(packet.getData(),0,packet.getLength()));
25         socket.close();//关闭连接
26     }
27 }

udp服务器端（简单udp通信的例子）

5: 使用UDP进行单向通信

 1 package Net;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.InputStreamReader;
 5 import java.net.DatagramPacket;
 6 import java.net.DatagramSocket;
 7 import java.net.InetSocketAddress;
 8 import java.net.SocketException;
 9 
10 /**
11  * author liulei
12  * data 5.27
13  * since 1.8
14  * version 1.0
15  * Description 基于udp的单方向聊天
16  */
17 public class Test61 {
18     public static void main(String[] args) throws Exception {
19         DatagramSocket socket = new DatagramSocket(8888);
20       while (true){
21           BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
22           String data = br.readLine();
23           byte[] datas = data.getBytes();
24           DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress("127.0.0.1",6666));
25           socket.send(packet);
26           if(data.equals("bye")){
27               break;
28           }
29       }
30         socket.close();
31     }
32 }

View Code

 1 package Net;
 2 
 3 
 4 
 5 import java.io.IOException;
 6 import java.net.DatagramPacket;
 7 import java.net.DatagramSocket;
 8 import java.net.SocketException;
 9 
10 /**
11  * author liulei
12  * data  5.27
13  * since 1.8
14  * version 1.0
15  * Description  基于udp的单方向聊天
16  */
17 public class Test62 {
18     public static void main(String[] args) throws IOException {
19         DatagramSocket socket = new DatagramSocket(6666);
20        while (true){
21            byte[] data = new byte[1024];
22            DatagramPacket packet = new DatagramPacket(data,0,data.length);
23            socket.receive(packet);
24            System.out.println(new String(packet.getData(),0,data.length));
25            String stringreceive = new String(packet.getData(),0,data.length);
26            if(stringreceive.equals("bye")){
27                break;
28            }
29        }
30         socket.close();
31 
32     }
33 }

View Code

6: 使用UDP进行双向通信

 1 package Net;
 2 
 3 import java.io.BufferedInputStream;
 4 import java.io.BufferedReader;
 5 import java.io.IOException;
 6 import java.io.InputStreamReader;
 7 import java.net.DatagramPacket;
 8 import java.net.DatagramSocket;
 9 import java.net.InetSocketAddress;
10 import java.net.SocketException;
11 
12 /**
13  * author liulei
14  * data 5.27
15  * since 1.8
16  * version 1.0
17  * Description  发送端
18  */
19 public class Test71 implements Runnable{
20     public static void main(String[] args) {
21 
22     }
23     DatagramSocket socket = null;
24     BufferedReader br = null;
25     DatagramPacket packet = null;
26     private String toIp;
27     private  int toPort;
28     private int fromPort;
29 
30     public Test71(int fromPort, int toPort, String toIp) throws Exception {
31         this.toIp = toIp;
32         this.toPort = toPort;
33         this.fromPort = fromPort;
34         socket = new DatagramSocket(fromPort);
35         br = new BufferedReader(new InputStreamReader(System.in));
36     }
37 
38     @Override
39     public void run() {
40         while (true){
41             String data = null;
42             try {
43                 data = br.readLine();
44 
45                 byte[] datas = data.getBytes();
46                 packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress(toIp,toPort));
47                 socket.send(packet);
48                 if(data.equals("bye")){
49                     break;
50                 }
51             } catch (IOException e) {
52                 e.printStackTrace();
53             }
54 
55         }
56         try {
57             br.close();
58             socket.close();
59         } catch (IOException e) {
60             e.printStackTrace();
61         }
62     }
63 }

发送端

 1 package Net;
 2 
 3 import java.io.IOException;
 4 import java.net.DatagramPacket;
 5 import java.net.DatagramSocket;
 6 import java.net.SocketException;
 7 
 8 /**
 9  * author liulei
10  * data
11  * since 1.8
12  * version 1.0
13  * Description 接收端
14  */
15 public class Test72 implements Runnable{
16     DatagramSocket socket = null;
17     private int port;
18     private String msgfrom;
19 
20     public Test72(int port, String msgfrom) throws SocketException {
21         this.port = port;
22         this.msgfrom = msgfrom;
23         socket = new DatagramSocket(port);
24     }
25 
26     @Override
27     public void run() {
28 
29         try {
30 
31             while (true){
32                 byte[] data = new byte[1024];
33                 DatagramPacket packet = new DatagramPacket(data,0,data.length);
34                 socket.receive(packet);
35                 String stringreceive = new String(packet.getData(),0,data.length);
36                 System.out.println(msgfrom + "："+ stringreceive);
37 
38                 if(stringreceive.equals("bye")){
39                     System.out.println(msgfrom + "断开连接");
40                     break;
41                 }
42 
43             }
44             socket.close();
45         } catch (IOException e) {
46             e.printStackTrace();
47         }
48 
49 
50     }
51 }

接收端

 1 package Net;
 2 
 3 /**
 4  * author liulei
 5  * data 5.27
 6  * since 1.8
 7  * version 1.0
 8  * Description  用户一
 9  */
10 public class Test73 {
11     public static void main(String[] args) throws Exception {
12         new Thread(new Test71(7777,9999,"localhost")).start();
13         new Thread(new Test72(8888,"用户二")).start();
14     }
15 }

用户一

 1 package Net;
 2 
 3 /**
 4  * author liulei
 5  * data  5.27
 6  * since 1.8
 7  * version 1.0
 8  * Description  用户二
 9  */
10 public class Test74{
11     public static void main(String[] args) throws Exception {
12         new Thread(new Test71(5555,8888,"localhost")).start();
13         new Thread(new Test72(9999,"用户一")).start();
14     }
15 }

用户二

7：域名解析

 1 package Net;
 2 
 3 import java.io.FileOutputStream;
 4 import java.io.IOException;
 5 import java.io.InputStream;
 6 import java.net.HttpURLConnection;
 7 import java.net.MalformedURLException;
 8 import java.net.URL;
 9 
10 /**
11  * author liulei
12  * data
13  * since 1.8
14  * version 1.0
15  * Description
16  */
17 public class Test8 {
18     public static void main(String[] args) throws IOException {
19         URL url = new URL("https://www.cnblogs.com/henuliulei/");
20         System.out.println(url.getPort());//端口
21         System.out.println(url.getHost());//ip
22         System.out.println(url.getProtocol());//协议
23         System.out.println(url.getPath());
24         System.out.println(url.getFile());
25         System.out.println("--------------分割线-------");
26         URL url1 = new URL("https://files.cnblogs.com/files/henuliulei/Java基础阶段笔记.zip");
27         //连接这个资源
28         HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
29         InputStream inputStream = urlConnection.getInputStream();
30         FileOutputStream fileOutputStream = new FileOutputStream("a.doc");
31         byte[] buffer = new byte[32768];
32         int len;
33         while ((len= inputStream.read(buffer))!=-1){
34             fileOutputStream.write(buffer,0,len);//写出数据
35         }
36         fileOutputStream.close();
37         inputStream.close();
38         urlConnection.disconnect();
39     }
40 }