How to expand and customize the use of the Inherits framework in the Java class library
How to expand and customize the use of the Inherits framework in the Java class library
Inherits is a very useful framework in the Java library. It provides a convenient way to expand and customize the function of existing libraries.This article will introduce the basic principles of the Inherits framework, and how to use it to achieve functional expansion and customization.
1. Basic principles of Inherits framework
The basic principle of the Inherits framework is to achieve functional expansion and customization by inheriting and rewriting the method of existing libraries.Through inheritance, all the methods and attributes of this class can be obtained, and these methods and attributes can be modified and expanded according to their own needs.
Second, expansion method of Inherits framework
1. Create a subclass
The first step of existing existing libraries is to create a subclass, which inherits the target class from the target class.For example, if you want to expand the functions of the java.util.arrayList class, you can create a new class MyArrayList, which inherited from the ArrayList class.
public class MyArrayList<E> extends ArrayList<E> {
// The method of rewring and extending the ArrayList class here
}
2. Rewriting method
The subclass inherits all the methods of the parent class, and the method can be rewritten as needed.Through the rewriting method, you can modify the behavior of the parent method, or add some additional functions.For example, you can rewrite the ADD method of the ArrayList class to perform some custom operations before adding elements.
public class MyArrayList<E> extends ArrayList<E> {
@Override
public boolean add(E e) {
// Operation before adding elements
// ...
// Call the parent -class ADD method
return super.add(e);
}
}
3. Add new method
In addition to rewriting existing methods, you can also add a new method to the subclass.These new methods can provide some additional functions for easy use in applications.For example, you can add a new method Printsize to the size of the list to print the list.
public class MyArrayList<E> extends ArrayList<E> {
public void printSize() {
System.out.println("Size: " + size());
}
}
Third, the customization of the inherits framework
1. Create interface
Inherits framework also provides a more flexible method to customize existing functions, that is, to create interfaces to define the function of expansion.First create an interface that includes the definition of expansion.
public interface MyList<E> {
boolean add(E e);
void printSize();
}
2. Implement interface
Next, create a class, implement this interface, and inherit the target class.This class needs to implement the method in the interface, and you can choose to rewrite other methods of the target class.
public class MyArrayList<E> extends ArrayList<E> implements MyList<E> {
@Override
public boolean add(E e) {
// Operation before adding elements
// ...
// Call the parent -class ADD method
return super.add(e);
}
@Override
public void printSize() {
System.out.println("Size: " + size());
}
}
Through the above steps, we can expand and customize the functions of existing libraries.Using the Inherits framework, without modifying the original code, it can easily realize the functional customization of the class library to improve the replication and scalability of the code.
Summarize
This article introduces the expansion and customization of the Inherits framework in the Java library.By inheriting and rewriting existing classes, or implementing the interface and inheriting the target class, we can easily expand and customize the function of the class library.With the Inherits framework, we can flexibly meet different functional needs on the basis of maintaining the stability of the existing library.I hope this article will help you understand and use the Inherits framework.
