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地球村:你在西安,你一个美国的朋友!
javaweb:网页编程 b/s架构
网络编程:TCP/IP c/s架构如何是实现网络的通信?
通信双发的地址:
规则:网络通信协议
TCP/IP参考模型:ip地址:InetAddress
//测试IPpublic class TestInetAddress { public static void main(String[] args) { try { //查询本机地址 InetAddress inetAddress1 = InetAddress.getByName("127.0.0.1"); System.out.println(inetAddress1); InetAddress inetAddress3 = InetAddress.getByName("localhost"); System.out.println(inetAddress3); InetAddress inetAddress4 = InetAddress.getLocalHost(); System.out.println(inetAddress4); //查询网站ip地址 InetAddress inetAddress2 = InetAddress.getByName("www.baidu.com"); System.out.println(inetAddress2); //常用方法 //System.out.println(inetAddress2.getAddress()); System.out.println(inetAddress2.getCanonicalHostName());//规范的名字 System.out.println(inetAddress2.getHostAddress());//ip System.out.println(inetAddress2.getHostName());//域名,或者自己电脑的名字 } catch (UnknownHostException e) { e.printStackTrace(); } }}
端口表示计算机上的一个程序的进程;
公有端口 0~1023
程序注册端口:1024~49151,分配给用户或者程序
动态、私有:49152~65535
1.netstat -ano #查看所有端口2.netstat -ano|findstr "5900" #查看指定的端口3.tasklist|findstr "8696" #查看指定端口的进程4.ctrl + shift + ESC #打开任务管理器
public class TestInetSocketAddress { public static void main(String[] args) { InetSocketAddress socketAddress = new InetSocketAddress("127.0.0.1", 8080); InetSocketAddress socketAddress2 = new InetSocketAddress("localhost", 8080); System.out.println(socketAddress); System.out.println(socketAddress2); System.out.println(socketAddress.getAddress()); System.out.println(socketAddress.getHostName());//地址 System.out.println(socketAddress.getPort());//端口 }}
协议:约定,就好比我们现在说的是普通话。
网络通信协议:速率,传输码率,代码结构,传输控制。。。。问题:非常的复杂?
大事化小:分层!
TCP/IP协议簇:实际上是一组协议
重要:
UDP:发短信
- 不连接,不稳定 - 客户端、服务端:没有明确的界限 - 不管有没有准备好,都可以发给你 - 导弹 - DDOS:洪水攻击!(饱和攻击)客户端
//客户端public class TcpClientDemo01 { public static void main(String[] args) { Socket socket = null; OutputStream os = null; try { //1.要知道服务器的地址 InetAddress byName = InetAddress.getByName("127.0.0.1"); //2.端口号 int port = 9999; //3.创建一个socket连接 socket = new Socket(byName,port); //4.发送消息 IO流 os = socket.getOutputStream(); os.write("您好,世界".getBytes()); } catch (Exception e) { e.printStackTrace(); }finally { if (os != null){ try { os.close(); } catch (IOException e) { e.printStackTrace(); } } if (socket != null){ try { socket.close(); } catch (IOException e) { e.printStackTrace(); } } } }}
服务器
//服务端public class TcpServerDemo01 { public static void main(String[] args) { ServerSocket serverSocket = null; Socket socket = null; InputStream is = null; ByteArrayOutputStream baos = null; try { //1.我得有一个地址 serverSocket = new ServerSocket(9999); while (true){ //2.等待客户端连接过来 socket = serverSocket.accept(); //3.读取客户端的消息 is = socket.getInputStream(); /* byte[] buffer = new byte[1024]; int len; while ((len=is.read(buffer))!=-1){ String msg = new String(buffer, 0, len); System.out.println(msg); } */ //管道流 baos = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; int len; while ((len=is.read(buffer))!=-1){ baos.write(buffer,0,len); } System.out.println(baos.toString()); } } catch (IOException e) { e.printStackTrace(); }finally { //关闭资源 if (baos !=null){ try { baos.close(); } catch (IOException e) { e.printStackTrace(); } } if (is != null){ try { is.close(); } catch (IOException e) { e.printStackTrace(); } } if (socket != null){ try { socket.close(); } catch (IOException e) { e.printStackTrace(); } } if (serverSocket != null){ try { serverSocket.close(); } catch (IOException e) { e.printStackTrace(); } } } }}
服务器端:
public class TcpServerDemo02 { public static void main(String[] args) throws IOException { //1.创建服务 ServerSocket serverSocket = new ServerSocket(9000); //2.监听客户端连接 Socket accept = serverSocket.accept();//阻塞式监听,会一直等待客户端 //3.获取输入流 InputStream is = accept.getInputStream(); //4.文件输出 FileOutputStream fos = new FileOutputStream("receive.png"); byte[] buffer = new byte[1024]; int len; while ((len = is.read(buffer))!= -1){ fos.write(buffer,0,len); } //通知客户端我接受完毕了 OutputStream os = accept.getOutputStream(); os.write("我接受完毕了,你可以断开了".getBytes()); //关闭资源 fos.close(); is.close(); accept.close(); serverSocket.close(); }}
客户端:
public class TcpClientDemo02 { public static void main(String[] args) throws IOException { //1.创建一个socket连接 Socket socket = new Socket(InetAddress.getByName("127.0.0.1"),9000); //2.创建一个输出流 OutputStream os = socket.getOutputStream(); //3.文件流 FileInputStream fis = new FileInputStream(new File("1.png")); //4.写出文件 byte[] buffer = new byte[1024]; int len; while ((len=fis.read(buffer))!=-1){ os.write(buffer,0,len); } //通知服务器,我已经结束了 socket.shutdownOutput();//我已经传输完了! //确定服务器接受完毕,才能够断开连接 InputStream is = socket.getInputStream(); //String byte[] ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] buffer2 = new byte[1024]; int len2; while ((len2 = is.read(buffer2))!=-1){ baos.write(buffer2,0,len2); } System.out.println(baos.toString()); //关闭资源 baos.close(); is.close(); fis.close(); os.close(); socket.close(); }}
服务端
客户端
发短信:不用连接,需要知道对方的地址
发送端://不需要连接服务器public class UdpClientDemo01 { public static void main(String[] args) throws Exception{ //1.建立一个Socket DatagramSocket socket = new DatagramSocket(); //2.建个包 String msg = "你好啊,服务器!"; //发送给谁 InetAddress localhost = InetAddress.getByName("localhost"); int port = 9090; //数据,数据的长度,要发送给谁 DatagramPacket packet = new DatagramPacket(msg.getBytes(), 0, msg.getBytes().length,localhost,port); //3.发送包 socket.send(packet); //4.关闭流 socket.close(); }}
接受端:
//还是要等待客户端的连接!public class UdpServerDeom01 { public static void main(String[] args) throws Exception { //开放端口 DatagramSocket socket = new DatagramSocket(9090); //接受数据包 byte[] buffer = new byte[1024]; DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);//接收 socket.receive(packet);//阻塞接收 System.out.println(packet.getAddress()); System.out.println(new String(packet.getData(),0,packet.getLength())); //关闭连接 socket.close(); }}
public class UdpSenderDemo01 { public static void main(String[] args) throws Exception { DatagramSocket socket = new DatagramSocket(8888); //准备数据:控制台读取System.in BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); while (true){ String data = reader.readLine(); byte[] datas = data.getBytes(); DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress("localhost",6666)); socket.send(packet); if (data.equals("bye")){ break; } } socket.close(); }}
循环接受消息
public class UdpReceiveDemo01 { public static void main(String[] args) throws Exception { DatagramSocket socket = new DatagramSocket(6666); while (true){ //准备接受包裹 byte[] container = new byte[1024]; DatagramPacket packet = new DatagramPacket(container,0,container.length); socket.receive(packet);//阻塞式接受包裹 //断开连接 bye byte[] data = packet.getData(); String receiveData = new String(data, 0, data.length); System.out.println(receiveData); if (receiveData.equals("bye")){ break; } } socket.close(); }}
在线咨询:两个人都可以是发送方,也都可以是接受方!
发送线程public class TalkSend implements Runnable { DatagramSocket socket = null; BufferedReader reader = null; private int fromPort; private String toIP; private int toPort; public TalkSend(int fromPort, String toIP, int toPort) { this.fromPort = fromPort; this.toIP = toIP; this.toPort = toPort; try { socket = new DatagramSocket(fromPort); reader = new BufferedReader(new InputStreamReader(System.in)); } catch (SocketException e) { e.printStackTrace(); } } @Override public void run() { while (true){ String data = null; try { data = reader.readLine(); byte[] datas = data.getBytes(); DatagramPacket packet = new DatagramPacket(datas, 0, datas.length, new InetSocketAddress(this.toIP, this.toPort)); socket.send(packet); if (data.equals("bye")){ break; } } catch (Exception e) { e.printStackTrace(); } } }}
接受线程
public class TalkReceive implements Runnable { DatagramSocket socket = null; private int port; private String msgFrom; public TalkReceive(int port,String msgFrom) { this.port = port; this.msgFrom = msgFrom; try { socket = new DatagramSocket(port); } catch (SocketException e) { e.printStackTrace(); } } @Override public void run() { try { while (true){ //准备接受包裹 byte[] container = new byte[1024]; DatagramPacket packet = new DatagramPacket(container,0,container.length); socket.receive(packet);//阻塞式接受包裹 //断开连接 bye byte[] data = packet.getData(); String receiveData = new String(data, 0, data.length); System.out.println(msgFrom+":"+receiveData); if (receiveData.equals("bye")){ break; } } }catch (Exception e){ e.printStackTrace(); } socket.close(); }}
示例
public class TalkStudent { public static void main(String[] args) { //开启两个线程 new Thread(new TalkSend(7777,"localhost",9999)).start(); new Thread(new TalkReceive(8888,"老师")).start(); }}
public class TalkTeacher { public static void main(String[] args) { new Thread(new TalkSend(5555,"localhost",8888)).start(); new Thread(new TalkReceive(9999,"student")).start(); }}
统一资源定位符:定位资源的,定位互联网上的某一个资源
DNS域名解析 https://www.baidu.com xxx.x…x…x
public class URLDemo01 { public static void main(String[] args) throws MalformedURLException { URL url = new URL("http://localhost:8080/helloworld/index.jsp?username=kuangshen&password=123"); System.out.println(url.getProtocol());//协议 System.out.println(url.getHost());//主机ip System.out.println(url.getPort());//端口 System.out.println(url.getPath());//文件 System.out.println(url.getFile());//全路径 System.out.println(url.getQuery());//参数 }}
下载资源
public class UrlDown { public static void main(String[] args) throws Exception { //1.下载地址 URL url = new URL("http://localhost:8080/qinjiang/SecurityFile.txt"); //2.连接到这个资源 HTTP HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); InputStream inputStream = urlConnection.getInputStream(); FileOutputStream fos = new FileOutputStream("SecurityFile.txt"); byte[] buffer = new byte[1024]; int len; while ((len = inputStream.read(buffer)) != -1){ fos.write(buffer,0,len);//写出这个数据 } fos.close(); inputStream.close(); urlConnection.disconnect();//断开连接 }}
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