The technical principles in the Java class library (technical principles of Constructor Framework in Java Class Libraries)

The "structure" framework of the technical principle in the Java class library In the Java library, the "structure" framework is an important technical principle.Structure mode is a design pattern that is used to create complex objects.It separates the object's creation from it, so that the same structure process can create different representations.The structural framework in the Java library provides a common way to achieve the structure and initialization of the object, thereby simplifying the task of developers. In Java, constructor is a special method for member variables that initialize objects when the object is created.The name of the constructor is the same as the class name, there is no return type, and automatically calls when using the `new` keyword to create an object.The structural framework in the Java class library uses the characteristics of the constructor, providing some standardized interfaces and template methods to further simplify the structure of the object. For example, the `java.util.hashmap` in the java library is a typical example of using a structure framework.When creating the `HashMap` object, different initialization methods can be selected through different constructors.The following is an example: // Use the default constructor to create a HashMap object HashMap<String, Integer> map1 = new HashMap<>(); // Use the preset initial capacity to create the HashMap object HashMap<String, Integer> map2 = new HashMap<>(100); // Use the preset initial capacity and load factor to create a HashMap object HashMap<String, Integer> map3 = new HashMap<>(100, 0.75f); In the above examples, by using different constructive functions, the appropriate initialization method can be selected according to the needs.This flexibility allows developers to customize objects to the objects according to the specific situation. The structure framework can also be forced to achieve specific initialization logic by defining abstract classes or interfaces.For example, the `java.io.inputstream` in the Java class library is an abstract class that is used to enter byte flow operations.This class defines an abstract method `Read`, which requires the subclass to implement this method.In this way, the structural framework can ensure that the necessary initialization logic is correctly implemented. In addition to the basic constructor, the structural framework in the Java class library also provides some other technical means to initialize the object.For example, using the factory mode can encapsulate the object's creation process in the factory class, so that the client only needs to call the factory method to obtain the object instance.This method can provide higher flexibility and maintenance. In summary, the structural framework in the Java class library is an important technical principle that is used to achieve the structure and initialization of the object.It provides flexible object creation by constructing functions and other technical means, and can enforce specific initialization logic.By calling a suitable constructor or using the factory mode, developers can easily create and initialize objects according to specific needs. Please note: The example of this article is only used to explain the purpose, and it may not be a complete running code.