A:IP地址 a:点分十进制 b:IP地址的组成 c:IP地址的分类 d:dos命令 e:InetAddress B:端口 是应用程序的标识。范围：0-65535。其中0-1024不建议使用。 C:协议 UDP:将数据源和目的封装成数据包中，不需要建立连接；每个数据报的大小在限制在64k；因无连接，是不可靠协议；不需要建立连接，速度快 TCP:建立连接，形成传输数据的通道；在连接中进行大数据量传输；通过三次握手完成连接，是可靠协议；必须建立连接，效率会稍低
A:通信两端都应该有Socket对象 B:所有的通信都是通过Socket间的IO进行操作的
发送： 创建UDP发送端的Socket对象 创建数据并把数据打包 发送数据 释放资源
package tongxin; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; /** * 创建UDP发送端的Socket对象 * 创建数据并把数据打包 * 发送数据 * 释放资源 * @author moon * */ public class SendDemo { public static void main(String[] args) throws IOException { //创建发送端的Socket对象 DatagramSocket ds = new DatagramSocket(); //封装键盘录入数据 BufferedReader bReader = new BufferedReader(new InputStreamReader(System.in)); String lineString = null; while((lineString = bReader.readLine()) != null) { if("886".equals(lineString)) { break; } //创建数据并打包 byte[] bys = lineString.getBytes(); DatagramPacket dPacket = new DatagramPacket(bys, bys.length, InetAddress.getByName("localhost"), 12345); //发送数据 ds.send(dPacket); } //释放资源 ds.close(); } }接收： 创建UDP接收端的Socket对象 创建数据包用于接收数据 接收数据 解析数据包 释放资源
package tongxin; import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; /** * * 创建UDP接收端的Socket对象 * 创建数据包用于接收数据 * 接收数据 * 解析数据包 * 释放资源 * @author moon * */ public class ReceiveDemo { public static void main(String[] args) throws IOException { //创建接收端的Socket对象 DatagramSocket dpSocket = new DatagramSocket(999); while(true) { //创建一个包裹 byte[] bys = new byte[1024]; DatagramPacket dpPacket = new DatagramPacket(bys, bys.length); //接收数据 dpSocket.receive(dpPacket); //解析数据 String ipString = dpPacket.getAddress().getHostAddress(); String s = new String(dpPacket.getData() , 0, dpPacket.getLength()); System.out.println("from " + ipString + "data is :" + s); } //释放资源 //dpSocket.close(); } }
发送： 创建TCP客户端的Socket对象 获取输出流，写数据 释放资源
package tongxin; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.Socket; public class ClientDemo { public static void main(String[] args) throws IOException { Socket socket = new Socket("localhost" , 7777); //获取输出流 OutputStream outputStream = socket.getOutputStream(); outputStream.write("你是小可爱吗".getBytes()); //获取输入流 InputStream inputStream = socket.getInputStream(); byte[] b = new byte[1024]; int len = inputStream.read(b); String client = new String(b, 0, len); System.out.println("client:" + client); socket.close(); } }接收： 创建TCP服务器端的Socket对象 监听客户端连接 获取输入流，读取数据 释放资源
package tongxin; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.ServerSocket; import java.net.Socket; public class ServerDemo { public static void main(String[] args) throws IOException { ServerSocket serverSocket = new ServerSocket(7777); Socket socket = serverSocket.accept(); //获取输入流 InputStream is = socket.getInputStream(); byte[] b = new byte[1024]; int len = is.read(b); String serve = new String(b, 0, len); System.out.println("serve: " + serve); //获取输出流 OutputStream os = socket.getOutputStream(); os.write("数据已收到".getBytes()); serverSocket.close(); socket.close(); } }A:UDP a:把发送数据改进为键盘录入
package lianxi; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; public class SendDemo { public static void main(String[] args) throws IOException { // 创建发送端的Socket对象 DatagramSocket ds = new DatagramSocket(); // 封装键盘录入数据 BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); String line = null; while ((line = br.readLine()) != null) { if ("886".equals(line)) { break; } // 创建数据并打包 byte[] bys = line.getBytes(); DatagramPacket dp = new DatagramPacket(bys, bys.length, InetAddress.getByName("localhost"), 12345); // 发送数据 ds.send(dp); } // 释放资源 ds.close(); } } package lianxi; import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; public class ReceiveDemo { public static void main(String[] args) throws IOException { // 创建接收端的Socket对象 DatagramSocket ds = new DatagramSocket(12345); while (true) { // 创建一个包裹 byte[] bys = new byte[1024]; DatagramPacket dp = new DatagramPacket(bys, bys.length); // 接收数据 ds.receive(dp); // 解析数据 String ip = dp.getAddress().getHostAddress(); String s = new String(dp.getData(), 0, dp.getLength()); System.out.println("from " + ip + " data is : " + s); } // 释放资源 // 接收端应该一直开着等待接收数据，是不需要关闭 // ds.close(); } }B:TCP d:客户端键盘录入服务器写到文本文件
package lianxi; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.Socket; /* * 键盘录入,服务器端以a.txt接收 */ public class ClientDemo { public static void main(String[] args) throws IOException { Socket socket = new Socket("localhost", 33333); //键盘录入 BufferedReader bReader = new BufferedReader(new InputStreamReader(System.in)); //把通道中的流给包装一下 BufferedWriter bWriter = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())); String line = null; while((line = bReader.readLine()) != null) { if("886".equals(line)) { break; } bWriter.write(line); bWriter.newLine(); bWriter.flush(); } socket.close(); } } package lianxi; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileWriter; import java.io.IOException; import java.io.InputStreamReader; import java.net.ServerSocket; import java.net.Socket; public class ServeDemo { public static void main(String[] args) throws IOException { ServerSocket serverSocket = new ServerSocket(33333); //监听客户端连接 Socket socket = serverSocket.accept(); //封装通道中的流 BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream())); //封装文本文档 BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("a.txt")); String lineString = null; while((lineString = bufferedReader.readLine()) != null) { bufferedWriter.write(lineString); bufferedWriter.newLine(); bufferedWriter.flush(); } bufferedWriter.close(); socket.close(); } }
