网络编程
TCP
客户端
- 连接服务器 Socket
- 发送消息
import java.io.IOException; import java.io.OutputStream; import java.net.InetAddress; import java.net.Socket; //客户端 public class TcpClientDemo01 { public static void main(String[] args) { Socket socket = null; OutputStream os = null; //1.要知道服务器的地址 try { InetAddress serverIP = InetAddress.getByName("127.0.0.1"); //2.端口号 int port = 9999; //3.创建一个socket连接 socket = new Socket(serverIP,port); //4.发送消息 IO流 os = socket.getOutputStream(); os.write("你好,欢迎学习狂神说Java".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
- 建立服务的端口 ServerSocket
- 等待用户的连接 accept
- 接受用户的消息
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.ServerSocket; import java.net.Socket; //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){ //连续接收客户端消息 //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(); } } } } }
TCP文件上传
服务器端
import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.net.ServerSocket; import java.net.Socket; public class TcpServerDemo02 { public static void main(String[] args) throws Exception { //1.创建服务 ServerSocket serverSocket = new ServerSocket(9000); //2.监听客户端的连接 Socket socket = serverSocket.accept();//阻塞式监听,会一直等待客户端连接 //3.获取输入流 InputStream is = socket.getInputStream(); //4.文件输出 FileOutputStream fos = new FileOutputStream("receive.jpg"); byte[] buffer = new byte[1024]; int len; while ((len = is.read(buffer))!=-1){ fos.write(buffer,0,len); } //通知客户端我接收完毕了 OutputStream os = socket.getOutputStream(); os.write("我接收完毕了,你可以断开了".getBytes()); //关闭资源 fos.close(); is.close(); socket.close(); serverSocket.close(); } }
客户端
import java.io.*; import java.net.InetAddress; import java.net.Socket; public class TcpClientDemo02 { public static void main(String[] args) throws Exception { //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.读取文件 FileInputStream fis = new FileInputStream(new File("D:\\environment\\java_project\\javase\\蜗牛.jpg")); //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! //确定服务器接收完毕,才能够断开连接 InputStream inputStream = socket.getInputStream(); //String byte[] ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] buffer2 = new byte[1024]; int len2; while ((len2 = inputStream.read(buffer2))!=-1){ baos.write(buffer2,0,len2); } System.out.println(baos.toString()); //5.关闭资源 baos.close(); inputStream.close(); fis.close(); os.close(); socket.close(); } }
Tomcat
服务器
- 自定义 S
- Tomcat 服务器 S:Java后台开发!
客户端
- 自定义 C
- 浏览器 B
UDP
发短信:不用连接,需要知道对方的地址
发送端
import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; //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,数据的长度起始,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(); } }
接收端
import java.net.DatagramPacket; import java.net.DatagramSocket; //还是要等待客户端的连接! public class UdpServerDemo01 { public static void main(String[] args) throws Exception { //开放端口 DatagramSocket socket = new DatagramSocket(9090); //接收数据包 byte[] buffer = new byte[1024]; DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);// socket.receive(packet);//阻塞接收 System.out.println(packet.getAddress().getHostAddress()); System.out.println(new String(packet.getData(),0, packet.getLength())); //关闭连接 socket.close(); } }
发送消息
import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetSocketAddress; 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(); } } ====================================================================================== import java.net.DatagramPacket; import java.net.DatagramSocket; 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);//阻塞式接收包裹 //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或接收方,实现在线交流)
import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetSocketAddress; 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 (Exception e){ e.printStackTrace(); } } @Override public void run() { while (true){ try { String 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(); } } socket.close(); } } ======================================================================================= import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.SocketException; 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() { while (true){ try { //准备接受包裹 byte[] container = new byte[1024]; DatagramPacket packet = new DatagramPacket(container,0,container.length); socket.receive(packet);//阻塞式接收包裹 //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 (IOException e){ e.printStackTrace(); } } socket.close(); } } ===================================================================================== 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,"学生")).start(); } }
URL下载网络资源
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 www.baidu.com xxx.x..x..x
协议://ip地址:端口/项目名/资源
import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; public class UrlDown { public static void main(String[] args) throws IOException { //1.下载地址 URL url = new URL("https://p2.music.126.net/WqnSe7WvZOB0E_4qBsNmqw==/109951166086703110.jpg?param=50y50"); //2.连接到这个资源 HTTP HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); InputStream inputStream = urlConnection.getInputStream(); FileOutputStream fos = new FileOutputStream("109951166086703110.jpg"); 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(); } }