The function and use of the core framework of the Java library

The Java Class Library is a set of pre -written Java classes to achieve common functions and tasks in Java applications.The Java class library core framework (Java Core Framework) is the basic part of the Java class library, which provides many important functions and tools that enable developers to create efficient and reliable applications. The functions and uses of the core framework of the Java library are as follows: 1. Basic data types and sets: Java class libraries provide basic data type packaging classes, such as Integer, Double and Boolean, making it easier to process basic data types.In addition, the Java library also provides many collection classes (such as ArrayList, LinkedList, Hashset, etc.) for storage and operation data. Example code: Integer num = 10; // Packaging class of basic data types ArrayList<String> list = new ArrayList<>(); // ArrayList集合 list.add("Java"); list.add("Python"); list.add("C++"); System.out.println (list); // Output: [java, python, c ++] 2. Input and output: The Java class library provides a large number of input and output classes for reading, reading and writing files from the console, and processing network communication.Among them, the commonly used input classes include `Scanner`, and commonly used output classes include` System.out` and `Printwriter`. Example code: Scanner scanner = New Scanner (System.in); // Read user input from the console System.out.println ("Please enter your name:"); String name = scanner.nextLine(); System.out.println ("Your name is:" + name); PrintWriter Writer = New Printwriter ("Output.txt"); // Write into the file writer.println("Hello, World!"); writer.close(); 3. Abnormal treatment: The Java library provides an abnormal processing mechanism, enabling developers to capture and handle abnormal conditions in the program.Specifically, the Java class library defines many abnormal classes, such as `` IOEXCEPTION, NullpoIntterexception`, and `numberFormatexception`, etc., as well as keywords used for abnormal processing` try-catch` and `Finally` and so on. Example code: try { int Result = 10 /0; // Except 0, triggering ArithmeticException System.out.println(result); } catch (ArithmeticException e) { System.out.println ("" Except for the abnormal operation of the method: " + e.getMessage ()); } finally { System.out.println ("Odoma is over.");); } 4. Thread and concurrency: Java class library provides many classes and interfaces for multi -threaded and concurrent programming.For example, the `Thread` class is used to create and manage threads, and the` Runnable` interface is used to define thread tasks. Example code: class MyRunnable implements Runnable { public void run() { System.out.println ("Thread mission is executed ..."); } } public class Main { public static void main(String[] args) { Thread Thread = New Thread (New Myrunnable ()); // Create a thread thread.start (); // Start thread } } In summary, the functions and uses of the core framework of the Java library cover many common development needs, including data processing, input and output, abnormal processing and concurrent programming.Developers can improve development efficiency by using the core framework of the Java library and create high -quality Java applications.