Introduction to the main features and functions of the Core framework in the Java class library
The Core framework in the Java class library is the core library of Java programming language. It provides many commonly used classes and methods to support the development and operation of Java applications.The main features and functions of the core framework are as follows:
1. Basic data types and data structures: Core framework provides packaging classes of various basic data types, such as Integer, Double, Boolean, etc., as well as various collection classes, such as List, SET, MAP, etc.These classes are convenient for processing and storage of data, providing rich methods and functions.
Example code:
Integer num = new Integer(10);
List<String> list = new ArrayList<String>();
list.add("Java");
list.add("Python");
2. Input output operation: Core framework provides class and methods for input and output, such as inputStream, OutputStream, Reader, Writer, etc.These classes can be used to read and write various input and output operations such as files, network communication.
Example code:
try {
File file = new File("input.txt");
InputStream inputStream = new FileInputStream(file);
byte[] data = new byte[(int) file.length()];
inputStream.read(data);
System.out.println(new String(data));
} catch (IOException e) {
e.printStackTrace();
}
3. Abnormal processing: The Core framework provides the Exception class and its subclasses for the abnormal conditions of the process.Developers can capture abnormalities with TRY-CATCH sentence blocks and processed accordingly.
Example code:
try {
int result = 10 / 0;
} catch (ArithmeticException e) {
System.out.println ("The division cannot be zero");
}
4. Multi -threaded support: The Core framework provides the Thread class and related classes and methods to achieve multi -threaded programming.Developers can create and manage multiple threads and control their execution order and concurrency operation.
Example code:
class MyThread extends Thread {
public void run() {
System.out.println ("thread starts to execute");
}
}
public class Main {
public static void main(String[] args) {
MyThread thread = new MyThread();
thread.start();
}
}
5. Time and date processing: Core framework provides categories and methods for time and date processing, such as Date, Calendar, etc.These classes can be used to obtain the current time, calculation time difference, formatting time string and other operations.
Example code:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date now = new Date();
System.out.println(sdf.format(now));
The Core framework in the Java class library is the foundation and core part of Java development, and has extensive applicationability and scalability.Developers can develop and maintain Java applications more efficiently by using these classes and methods.
