Day 7 Java周末总结测试

import java.net.InetAddress; import java.net.UnknownHostException; public class InetAddressExample { public static void main(String[] args) { try { // 获取本地主机地址 InetAddress localHost = InetAddress.getLocalHost(); System.out.println("Local Host: " + localHost); // 通过主机名获取IP InetAddress googleAddr = InetAddress.getByName("www.google.com"); System.out.println("Google IP: " + googleAddr.getHostAddress()); // 获取所有IP地址 InetAddress[] allGoogleIps = InetAddress.getAllByName("www.google.com"); for (InetAddress ip : allGoogleIps) { System.out.println("Google IP: " + ip.getHostAddress()); } } catch (UnknownHostException e) { e.printStackTrace(); } } }

import java.io.*; import java.net.*; public class TCPServer { public static void main(String[] args) { final int PORT = 8888; try (ServerSocket serverSocket = new ServerSocket(PORT)) { System.out.println("TCP Server started on port " + PORT); while (true) { // 等待客户端连接 Socket clientSocket = serverSocket.accept(); System.out.println("Client connected: " + clientSocket.getInetAddress().getHostAddress()); // 获取输入输出流 BufferedReader in = new BufferedReader( new InputStreamReader(clientSocket.getInputStream())); PrintWriter out = new PrintWriter( clientSocket.getOutputStream(), true); // 读取客户端消息 String message = in.readLine(); System.out.println("Received: " + message); // 发送响应 out.println("Echo: " + message); // 关闭连接 clientSocket.close(); } } catch (IOException e) { e.printStackTrace(); } } }

import java.io.*; import java.net.*; public class TCPClient { public static void main(String[] args) { final String SERVER_IP = "localhost"; final int PORT = 8888; try (Socket socket = new Socket(SERVER_IP, PORT)) { // 获取输入输出流 PrintWriter out = new PrintWriter( socket.getOutputStream(), true); BufferedReader in = new BufferedReader( new InputStreamReader(socket.getInputStream())); // 发送消息 out.println("Hello TCP Server!"); // 读取响应 String response = in.readLine(); System.out.println("Server response: " + response); } catch (IOException e) { e.printStackTrace(); } } }

import java.net.*; public class UDPServer { public static void main(String[] args) { final int PORT = 9999; try (DatagramSocket socket = new DatagramSocket(PORT)) { System.out.println("UDP Server started on port " + PORT); byte[] buffer = new byte[1024]; while (true) { // 准备接收数据包 DatagramPacket packet = new DatagramPacket(buffer, buffer.length); // 接收数据 socket.receive(packet); // 解析数据 String message = new String(packet.getData(), 0, packet.getLength()); System.out.println("Received from " + packet.getAddress() + ": " + message); // 准备响应数据 String response = "UDP Response: " + message; byte[] responseData = response.getBytes(); // 发送响应 DatagramPacket responsePacket = new DatagramPacket( responseData, responseData.length, packet.getAddress(), packet.getPort()); socket.send(responsePacket); } } catch (IOException e) { e.printStackTrace(); } } }

import java.net.*; public class UDPClient { public static void main(String[] args) { final String SERVER_IP = "localhost"; final int PORT = 9999; try (DatagramSocket socket = new DatagramSocket()) { // 准备发送数据 String message = "Hello UDP Server!"; byte[] sendData = message.getBytes(); // 创建发送包 InetAddress serverAddress = InetAddress.getByName(SERVER_IP); DatagramPacket sendPacket = new DatagramPacket( sendData, sendData.length, serverAddress, PORT); // 发送数据 socket.send(sendPacket); System.out.println("Sent: " + message); // 准备接收响应 byte[] receiveData = new byte[1024]; DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length); // 设置超时时间（2秒） socket.setSoTimeout(2000); // 接收响应 socket.receive(receivePacket); String response = new String(receivePacket.getData(), 0, receivePacket.getLength()); System.out.println("Server response: " + response); } catch (IOException e) { e.printStackTrace(); } } }

import java.io.*; import java.net.*; public class HttpGetExample { public static void main(String[] args) { try { URL url = new URL("https://jsonplaceholder.typicode.com/posts/1"); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); // 设置请求方法 conn.setRequestMethod("GET"); // 设置请求头 conn.setRequestProperty("User-Agent", "Java HTTP Client"); // 获取响应码 int responseCode = conn.getResponseCode(); System.out.println("Response Code: " + responseCode); // 读取响应内容 if (responseCode == HttpURLConnection.HTTP_OK) { BufferedReader in = new BufferedReader( new InputStreamReader(conn.getInputStream())); String inputLine; StringBuilder response = new StringBuilder(); while ((inputLine = in.readLine()) != null) { response.append(inputLine); } in.close(); System.out.println("Response: " + response.toString()); } else { System.out.println("GET request failed"); } } catch (IOException e) { e.printStackTrace(); } } }

import java.io.*; import java.nio.*; import java.nio.channels.FileChannel; public class FileCopyExample { public static void main(String[] args) { String sourceFile = "source.txt"; String destFile = "destination.txt"; try (FileInputStream fis = new FileInputStream(sourceFile); FileOutputStream fos = new FileOutputStream(destFile); FileChannel sourceChannel = fis.getChannel(); FileChannel destChannel = fos.getChannel()) { // 创建缓冲区 ByteBuffer buffer = ByteBuffer.allocate(1024); while (sourceChannel.read(buffer) != -1) { // 切换为读模式 buffer.flip(); // 写入到目标通道 destChannel.write(buffer); // 清空缓冲区（为下一次读取准备） buffer.clear(); } System.out.println("File copied successfully!"); } catch (IOException e) { e.printStackTrace(); } } }

import java.io.*; import java.net.*; import java.util.concurrent.*; public class MultiThreadedServer { private static final int PORT = 8888; private static final int THREAD_POOL_SIZE = 10; public static void main(String[] args) { ExecutorService executor = Executors.newFixedThreadPool(THREAD_POOL_SIZE); try (ServerSocket serverSocket = new ServerSocket(PORT)) { System.out.println("Multi-threaded server started on port " + PORT); while (true) { Socket clientSocket = serverSocket.accept(); System.out.println("New client connected: " + clientSocket.getInetAddress().getHostAddress()); // 为每个客户端连接创建任务 executor.execute(new ClientHandler(clientSocket)); } } catch (IOException e) { e.printStackTrace(); } finally { executor.shutdown(); } } static class ClientHandler implements Runnable { private final Socket clientSocket; public ClientHandler(Socket socket) { this.clientSocket = socket; } @Override public void run() { try (BufferedReader in = new BufferedReader( new InputStreamReader(clientSocket.getInputStream())); PrintWriter out = new PrintWriter( clientSocket.getOutputStream(), true)) { String inputLine; while ((inputLine = in.readLine()) != null) { System.out.println("[" + Thread.currentThread().getName() + "] Received: " + inputLine); // 处理请求并返回响应 String response = "Processed: " + inputLine; out.println(response); } } catch (IOException e) { System.out.println("Error handling client: " + e.getMessage()); } finally { try { clientSocket.close(); } catch (IOException e) { e.printStackTrace(); } } } } }