26.06網絡編程三要素之端口

物理端口網卡口

邏輯端口

1:每個網絡程序都會至少有一個邏輯端口

2:用于標識進程的邏輯地址，不同進程的標識

3:有效端口:0~65535，其中0~1024系統使用或保留端口

協議:通訊的規則，常見協議:TCP，UDP

UDP:

1.將數據源和目的封裝成數據包中，不需要建立連接

2.每個數據報的大小在限制在64k

3.因無連接，是不可靠協議

4.不需要建立連接，速度快

TCP:

1.建立連接，形成傳輸數據的通道

2.在連接中進行大數據量傳輸

3.通過三次握手完成連接，是可靠協議

4.必須建立連接，效率會稍低

Socket套接字:網絡上具有唯一標識的IP地址和端口號組合在一起才能構成唯一能識別的標識符套接字

Socket原理機制:

1.通信的兩端都有Socket

2.網絡通信其實就是Socket間的通信

3.數據在兩個Socket間通過IO傳輸

DatagramSocket:此類表示用來發送和接收數據報包的套接字。數據報套接字是包投遞服務的發送或接收點。

DatagramPacket:此類表示數據報包。數據報包用來實現無連接包投遞服務。

發送端步驟:

1:建立udp的socket服務

2:將要發送的數據封裝成數據包

3:通過udp的socket服務,將數據包發送出

4:關閉資源

例:

 1 public class Send  2 { 3     public static void main(String[] args) throws IOException  4     { 5         // 創建發送端Socket對象 6         DatagramSocket ds = new DatagramSocket(); 7  8         // 創建數據 9         byte[] bys = "hello,udp,我來了".getBytes();10         // 長度11         int length = bys.length;12         // IP地址對象13         InetAddress address = InetAddress.getByName("192.168.12.92");14         // 端口15         int port = 10086;16         17         //將數據打包，包含內容、長度、IP地址、端口號18         DatagramPacket dp = new DatagramPacket(bys, length, address, port);19 20         // 發送數據包21         ds.send(dp);22 23         // 釋放資源24         ds.close();25     }26 }

26.10UDP協議接收數據

接收端步驟:

1:建立udp的socket服務.

2:通過receive方法接收數據

3:將收到的數據存儲到數據包對象中

4:通過數據包對象的功能來完成對接收到數據進行解析

5:可以對資源進行關閉

例:

 1 public class Receive  2 { 3     public static void main(String[] args) throws IOException  4     { 5         // 創建接收端Socket對象 6         DatagramSocket ds = new DatagramSocket(10000); 7  8         // 創建一個數據包(接收容器) 9         byte[] bys = new byte[1024];10         int length = bys.length;11         DatagramPacket dp = new DatagramPacket(bys, length);12 13         // 調用Socket對象的接收方法接收數據14         ds.receive(dp); // 阻塞式15 16         // 解析數據包17         // 獲取對方的ip18         InetAddress address = dp.getAddress();19         String ip = address.getHostAddress();20         // 獲取數據緩沖區21         byte[] bys2 = dp.getData();22         // 獲取數據的實際長度23         int len = dp.getLength();24         String s = new String(bys2, 0, len);25         System.out.println("ip:"+ip);26         System.out.println("傳遞的數據:"+ s);27         // 釋放資源28         ds.close();29     }30 }

26.11UDP協議發送和接收數據代碼優化

例:

 1 public class Send  2 { 3     public static void main(String[] args) throws IOException  4     { 5         // 創建發送端的Socket對象 6         DatagramSocket ds = new DatagramSocket(); 7  8         // 創建數據并打包 9         byte[] bys = "helloworld".getBytes();10         DatagramPacket dp = new DatagramPacket(bys, bys.length,11                 InetAddress.getByName("192.168.1.99"), 10001);12 13         // 發送數據14         ds.send(dp);15 16         // 釋放資源17         ds.close();18     }19 }20 21 --------------------------------------------------------------22 public class Receive 23 {24     public static void main(String[] args) throws IOException 25     {26         // 創建接收端的Socket對象27         DatagramSocket ds = new DatagramSocket(10001);28 29         // 創建一個包裹30         byte[] bys = new byte[1024];31         DatagramPacket dp = new DatagramPacket(bys, bys.length);32 33         // 接收數據34         ds.receive(dp);35 36         // 解析數據37         String ip = dp.getAddress().getHostAddress();38         String s = new String(dp.getData(), 0, dp.getLength());39         System.out.println("ip:" + ip);40         System.out.println("數據:" + s);41 42         // 釋放資源43         ds.close();44     }45 }

26.12發送端的數據來自于鍵盤錄入案例

從鍵盤錄入數據進行發送，如果輸入的是886那么客戶端就結束輸入數據。

 1 public class Send  2 { 3     public static void main(String[] args) throws IOException  4     { 5         // 創建發送端的Socket對象 6         DatagramSocket ds = new DatagramSocket(); 7  8         // 封裝鍵盤錄入數據 9         BufferedReader br = new BufferedReader(new InputStreamReader(System.in));10         String line = null;11         while ((line = br.readLine()) != null) 12         {13             if ("886".equals(line)) 14             {15                 break;16             }17 18             // 創建數據并打包19             byte[] bys = line.getBytes();20             DatagramPacket dp = new DatagramPacket(bys, bys.length,21                     InetAddress.getByName("192.168.1.99"), 10001);22             //192.168.1.255為廣播地址23 24             // 發送數據25             ds.send(dp);26         }27 28         // 釋放資源29         ds.close();30     }31 }32 --------------------------------------------------------------33 public class Receive 34 {35     public static void main(String[] args) throws IOException 36     {37         // 創建接收端的Socket對象38         DatagramSocket ds = new DatagramSocket(10001);39 40         while (true) 41         {42             // 創建一個包裹43             byte[] bys = new byte[1024];44             DatagramPacket dp = new DatagramPacket(bys, bys.length);45 46             // 接收數據47             ds.receive(dp);48 49             // 解析數據50             String ip = dp.getAddress().getHostAddress();51             String s = new String(dp.getData(), 0, dp.getLength());52             System.out.println("from " + ip + " data is : " + s);53         }54 55         // 釋放資源56         // 接收端應該一直開著等待接收數據，是不需要關閉57         // ds.close();58     }59 }

26.13多線程實現聊天室程序

 1 public class Practice  2 { 3     public static void main(String[] args) throws IOException 4     { 5         DatagramSocket dsSend = new DatagramSocket(); 6         DatagramSocket dsReceive = new DatagramSocket(10001); 7  8         Send st = new Send(dsSend); 9         Receive rt = new Receive(dsReceive);10 11         Thread t1 = new Thread(st);12         Thread t2 = new Thread(rt);13 14         t1.start();15         t2.start();16     }17 }18 --------------------------------------------------------------19 發送端:20 public class Send implements Runnable21 {22     private DatagramSocket ds;23 24     public Send(DatagramSocket ds) 25     {26         this.ds = ds;27     }28 29     @Override30     public void run() 31     {32         try 33         {34             // 封裝鍵盤錄入數據35             BufferedReader br = new BufferedReader(new InputStreamReader(System.in));36             String line = null;37             while ((line = br.readLine()) != null) 38             {39                 if ("886".equals(line)) 40                 {41                     break;42                 }43 44                 // 創建數據并打包45                 byte[] bys = line.getBytes();46                 DatagramPacket dp = new DatagramPacket(bys, bys.length,InetAddress.getByName("192.168.1.255"), 10001);47 48                 // 發送數據49                 ds.send(dp);50             }51 52             // 釋放資源53             ds.close();54         } 55         catch (IOException e)56         {57             e.printStackTrace();58         }59     }60 }61 --------------------------------------------------------------62 接收端:63 public class Receive implements Runnable64 {65     private DatagramSocket ds;66 67     public Receive(DatagramSocket ds)68     {69         this.ds = ds;70     }71 72     @Override73     public void run() 74     {75         try 76         {77             while (true) 78             {79                 // 創建一個包裹80                 byte[] bys = new byte[1024];81                 DatagramPacket dp = new DatagramPacket(bys, bys.length);82 83                 // 接收數據84                 ds.receive(dp);85 86                 // 解析數據87                 String ip = dp.getAddress().getHostAddress();88                 String s = new String(dp.getData(), 0, dp.getLength());89                 System.out.println("來自" + ip + "的數據: " + s);90             }91         } 92         catch (IOException e)93         {94             e.printStackTrace();95         }96     }97 }

26.14TCP協議發送數據

TCP協議發送數據:

A:創建發送端的Socket對象，這一步如果成功，就說明連接已經建立成功了

B:獲取輸出流，寫數據

C:釋放資源

TCP協議一定要先開服務器。否則報錯:java.net.ConnectException:Connectionrefused:connect

publicSocket(Stringhost,intport)throwsUnknownHostException,IOException

創建一個流套接字并將其連接到指定主機上的指定端口號。

例:

 1 public class Client  2 { 3     public static void main(String[] args) throws IOException  4     { 5         // 創建發送端的Socket對象 6         // Socket(InetAddress address, int port) 7         // Socket(String host, int port) 8         // Socket s = new Socket(InetAddress.getByName("192.168.1.88"), 10002); 9         Socket s = new Socket("192.168.1.88", 10002);10 11         // 獲取輸出流，寫數據12         // public OutputStream getOutputStream()13         OutputStream os = s.getOutputStream();14         os.write("hello,tcp".getBytes());15 16         // 釋放資源17         s.close();18     }19 }

26.15TCP協議接收數據

TCP協議接收數據:

A:創建接收端的Socket對象

B:監聽客戶端連接。返回一個對應的Socket對象

C:獲取輸入流，讀取數據顯示在控制臺

D:釋放資源

例:

 1 public class Server  2 { 3     public static void main(String[] args) throws IOException 4     { 5         // 創建接收端的Socket對象 6         // ServerSocket(int port) 7         ServerSocket ss = new ServerSocket(10002); 8      9         // 監聽客戶端連接。返回一個對應的Socket對象10         // public Socket accept()11         Socket s = ss.accept(); // 偵聽并接受到此套接字的連接。此方法在連接傳入之前一直阻塞。12     13         // 獲取輸入流，讀取數據顯示在控制臺14         InputStream is = s.getInputStream();15     16         byte[] bys = new byte[1024];17         int len = is.read(bys); // 阻塞式方法18         String str = new String(bys, 0, len);19     20         String ip = s.getInetAddress().getHostAddress();21     22         System.out.println(ip + "---" + str);23     24         // 釋放資源25         s.close();26         // ss.close(); //這個不應該關閉27     }28 }

26.16服務器給客戶端一個反饋案例

 1 //服務端 2 public class Server  3 { 4     public static void main(String[] args) throws IOException 5     { 6         // 創建服務器Socket對象 7         ServerSocket ss = new ServerSocket(10002); 8  9         // 監聽客戶端的連接10         Socket s = ss.accept(); // 阻塞11 12         // 獲取輸入流13         InputStream is = s.getInputStream();14         byte[] bys = new byte[1024];15         int len = is.read(bys); // 阻塞16         String server = new String(bys, 0, len);17         System.out.println("server:" + server);18 19         // 獲取輸出流20         OutputStream os = s.getOutputStream();21         os.write("數據已經收到".getBytes());22 23         // 釋放資源24         s.close();25         // ss.close();26     }27 }28 --------------------------------------------------------------29 //客戶端30 public class Client 31 {32     public static void main(String[] args) throws IOException 33     {34         // 創建客戶端Socket對象35         Socket s = new Socket("192.168.1.88", 10002);36 37         // 獲取輸出流38         OutputStream os = s.getOutputStream();39         os.write("hello".getBytes());40 41         // 獲取輸入流42         InputStream is = s.getInputStream();43         byte[] bys = new byte[1024];44         int len = is.read(bys);// 阻塞45         String client = new String(bys, 0, len);46         System.out.println("client:" + client);47 48         // 釋放資源49         s.close();50     }51 }

26.17客戶端鍵盤錄入服務器控制臺輸出

 1 //服務端 2 public class Server  3 { 4     public static void main(String[] args) throws IOException 5     { 6         // 創建服務器Socket對象 7         ServerSocket ss = new ServerSocket(10003); 8  9         // 監聽客戶端連接10         Socket s = ss.accept();11 12         // 包裝通道內容的流13         BufferedReader br = new BufferedReader(new InputStreamReader(14                 s.getInputStream()));15         String line = null;16         while ((line = br.readLine()) != null) 17         {18             System.out.println(line);19         }20 21         // br.close();22         s.close();23         // ss.close();24     }25 }26 --------------------------------------------------------------27 //客戶端28 public class Client 29 {30     public static void main(String[] args) throws IOException 31     {32         // 創建客戶端Socket對象33         Socket s = new Socket("192.168.1.88", 10003);34 35         // 鍵盤錄入數據36         BufferedReader br = new BufferedReader(new InputStreamReader(System.in));37         // 把通道內的流給包裝一下38         BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(39                 s.getOutputStream()));40 41         String line = null;42         while ((line = br.readLine()) != null) 43         {44             // 鍵盤錄入數據要自定義結束標記45             if ("886".equals(line)) 46             {47                 break;48             }49             bw.write(line);50             bw.newLine();51             bw.flush();52         }53 54         // 釋放資源55         // bw.close();56         // br.close();57         s.close();58     }59 }

26.18TCP上傳文本文件并給出反饋

 1 //服務端 2 public class Server  3 { 4     public static void main(String[] args) throws IOException 5     { 6         // 創建服務器端的Socket對象 7         ServerSocket ss = new ServerSocket(10003); 8  9         // 監聽客戶端連接10         Socket s = ss.accept();// 阻塞11 12         // 封裝通道內的流13         BufferedReader br = new BufferedReader(new InputStreamReader(14                 s.getInputStream()));15         // 封裝文本文件16         BufferedWriter bw = new BufferedWriter(new FileWriter("Copy.java"));17 18         String line = null;19         while ((line = br.readLine()) != null) 20         { 21             // 阻塞22             // if("over".equals(line)){23             // break;24             // }25             bw.write(line);26             bw.newLine();27             bw.flush();28         }29 30         // 給出反饋31         BufferedWriter bwServer = new BufferedWriter(new OutputStreamWriter(32                 s.getOutputStream()));33         bwServer.write("文件上傳成功");34         bwServer.newLine();35         bwServer.flush();36 37         // 釋放資源38         bw.close();39         s.close();40     }41 }42 --------------------------------------------------------------43 //客戶端44 public class Client 45 {46     public static void main(String[] args) throws IOException 47     {48         // 創建客戶端Socket對象49         Socket s = new Socket("192.168.1.99", 10003);50 51         // 封裝文本文件52         BufferedReader br = new BufferedReader(new FileReader(53                 "InetAddressDemo.java"));54         // 封裝通道內流55         BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(56                 s.getOutputStream()));57 58         String line = null;59         while ((line = br.readLine()) != null) 60         { // 阻塞61             bw.write(line);62             bw.newLine();63             bw.flush();64         }65         66         //自定義一個結束標記67 //                bw.write("over");68 //                bw.newLine();69 //                bw.flush();70         71         //Socket提供了一個終止，它會通知服務器沒有數據過來了72         s.shutdownOutput();73 74         // 接收反饋75         BufferedReader brClient = new BufferedReader(new InputStreamReader(76                 s.getInputStream()));77         String client = brClient.readLine(); // 阻塞78         System.out.println(client);79 80         // 釋放資源81         br.close();82         s.close();83     }84 }

26.19TCP協議上傳圖片并給出反饋

 1 //服務端 2 public class Server  3 { 4     public static void main(String[] args) throws IOException 5     { 6         // 創建服務器Socket對象 7         ServerSocket ss = new ServerSocket(10004); 8  9         // 監聽客戶端連接10         Socket s = ss.accept();11 12         // 封裝通道內流13         BufferedInputStream bis = new BufferedInputStream(s.getInputStream());14         // 封裝圖片文件15         BufferedOutputStream bos = new BufferedOutputStream(16                 new FileOutputStream("D://bj.jpg"));17 18         byte[] bys = new byte[1024];19         int len = 0;20         while ((len = bis.read(bys)) != -1) 21         {22             bos.write(bys, 0, len);23             bos.flush();24         }25 26         // 給一個反饋27         OutputStream os = s.getOutputStream();28         os.write("圖片上傳成功".getBytes());29 30         bos.close();31         s.close();32     }33 }34 --------------------------------------------------------------35 //客戶端36 public class Client 37 {38     public static void main(String[] args) throws IOException 39     {40         // 創建客戶端Socket對象41         Socket s = new Socket("192.168.1.88", 10004);42 43         // 封裝圖片文件44         BufferedInputStream bis = new BufferedInputStream(new FileInputStream(45                 "D://001.jpg"));46         // 封裝通道內的流47         BufferedOutputStream bos = new BufferedOutputStream(s.getOutputStream());48 49         byte[] bys = new byte[1024];50         int len = 0;51         while ((len = bis.read(bys)) != -1) 52         {53             bos.write(bys, 0, len);54             bos.flush();55         }56         57         s.shutdownOutput();58 59         // 讀取反饋60         InputStream is = s.getInputStream();61         byte[] bys2 = new byte[1024];62         int len2 = is.read(bys2);63         String client = new String(bys2, 0, len2);64         System.out.println(client);65 66         // 釋放資源67         bis.close();68         s.close();69     }70 }

26.20多線程改進多個客戶端上傳文件案例

  1 //用戶線程  2 public class UserThread implements Runnable  3 {  4     private Socket s;  5   6     public UserThread(Socket s)  7     {  8         this.s = s;  9     } 10  11     @Override 12     public void run()  13     { 14         try  15         { 16             // 封裝通道內的流 17             BufferedReader br = new BufferedReader(new InputStreamReader( 18                     s.getInputStream())); 19             // 封裝文本文件 20             // BufferedWriter bw = new BufferedWriter(new 21             // FileWriter("Copy.java")); 22  23             // 為了防止名稱沖突 24             String newName = System.currentTimeMillis() + ".java"; 25             BufferedWriter bw = new BufferedWriter(new FileWriter(newName)); 26  27             String line = null; 28             while ((line = br.readLine()) != null)  29             { // 阻塞 30                 bw.write(line); 31                 bw.newLine(); 32                 bw.flush(); 33             } 34  35             // 給出反饋 36             BufferedWriter bwServer = new BufferedWriter( 37                     new OutputStreamWriter(s.getOutputStream())); 38             bwServer.write("文件上傳成功"); 39             bwServer.newLine(); 40             bwServer.flush(); 41  42             // 釋放資源 43             bw.close(); 44             s.close(); 45         }  46         catch (IOException e)  47         { 48             e.printStackTrace(); 49         } 50     } 51 } 52 -------------------------------------------------------------- 53 //服務端 54 public class Server  55 { 56     public static void main(String[] args) throws IOException 57     { 58         // 創建服務器Socket對象 59         ServerSocket ss = new ServerSocket(10005); 60  61         while (true)  62         { 63             Socket s = ss.accept(); 64             new Thread(new UserThread(s)).start(); 65         } 66     } 67 } 68 -------------------------------------------------------------- 69 //客戶端 70 public class Client  71 { 72     public static void main(String[] args) throws IOException  73     { 74         // 創建客戶端Socket對象 75         Socket s = new Socket("192.168.1.99", 10005); 76  77         // 封裝文本文件 78         // BufferedReader br = new BufferedReader(new FileReader( 79         // "InetAddressDemo.java")); 80         BufferedReader br = new BufferedReader(new FileReader( 81                 "ReceiveDemo.java")); 82         // 封裝通道內流 83         BufferedWriter bw = new BufferedWriter(new OutputStreamWriter( 84                 s.getOutputStream())); 85  86         String line = null; 87         while ((line = br.readLine()) != null)  88         { // 阻塞 89             bw.write(line); 90             bw.newLine(); 91             bw.flush(); 92         } 93  94         // Socket提供了一個終止，它會通知服務器你別等了，我沒有數據過來了 95         s.shutdownOutput(); 96  97         // 接收反饋 98         BufferedReader brClient = new BufferedReader(new InputStreamReader( 99                 s.getInputStream()));100         String client = brClient.readLine(); // 阻塞101         System.out.println(client);102 103         // 釋放資源104         br.close();105         s.close();106     }107 }