IO operation and network programming in the core framework in the Java class library

The core framework in the Java class library provides rich IO operation and network programming functions, allowing developers to easily process file input and output and network communication.In the Java class library, IO operation and network programming are very important parts, and it is also a need for development in development. In Java, the IO operation mainly includes the read -writing, input and output stream processing of files, and the input and output operation of various types.The Java class library provides rich classes and methods to implement these functions, including File, FileInputStream, FileoutPutstream, Reader, Writer, etc.Developers can use these classes and methods to implement the read and write operation of files, including reading file content, writing data to files, copy files, deleting files, etc. In terms of network programming, the Java class library also provides very complete support.Developers can use Java's network programming classes to implement network communication functions, including Socket, Serversocket, UrlConnection, etc.Through these classes, data transmission, network connection establishment and management between client and server can be realized. Below is a simple Java network programming example, demonstrating how to use the socket class to achieve communication between clients and servers: import java.io.*; import java.net.*; public class Client { public static void main(String[] args) { try { // Create a socket object, specify the server address and port number Socket socket = new Socket("127.0.0.1", 8888); // Get the output stream to send data to the server OutputStream os = socket.getOutputStream(); PrintWriter pw = new PrintWriter(os); pw.write("Hello, Server"); pw.flush(); // Get the input flow to receive data sent by the server InputStream is = socket.getInputStream(); BufferedReader br = new BufferedReader(new InputStreamReader(is)); String message = br.readLine(); System.out.println("Received message from server: " + message); // Close the resource br.close(); is.close(); pw.close(); os.close(); socket.close(); } catch (IOException e) { e.printStackTrace(); } } } In this example, we created a client to establish a connection with the specified server through the socket object, and realize the function of sending data to the server and receiving the server back to the data. In addition to the above examples, there are many other IO operations and network programming classes and methods, which can be selected and used according to specific needs.The core framework in the Java class library provides rich functions and tools that can help developers to easily realize various IO operations and network programming needs.