What are javabeans?

JavaBean is a reusable component written in JAVA language. It is a special Java class that becomes an object bean with a certain function or handles a certain business by encapsulating properties and methods.

JavaBean is a reusable component written in JAVA language. To be written as a JavaBean, a class must be concrete and public, and have a parameterless constructor. JavaBean exposes member properties of internal fields by providing public methods that conform to consistent design patterns, and can be obtained by set and get methods. As we all know, the property names conform to this pattern, and other Java classes can discover and manipulate the properties of these JavaBeans through the introspection mechanism (reflection mechanism).

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JavaBean is a reusable Java component that can be called by Java applications such as Applet, Servlet, SP, etc. It can also be used visually by Java development tools. It includes properties (Properties), methods (Methods), events (Events) and other features.

JavaBeans are a software component model, just like ActiveX controls, they provide known functionality and can be easily reused and integrated into Java classes in applications.

Any object that can be created with Java code can be encapsulated using JavaBeans. By rationally organizing JavaBeans with different functions, a new application can be quickly generated. If this application is compared to a car, then these JavaBeans are like the different parts that make up the car. For software developers, the biggest advantage brought by JavaBeans is that it fully improves the reusability of code and plays a positive role in the maintainability and ease of maintenance of software.

The types of JavaBeans can be divided into two categories: visual and non-visual according to their functions.

Visual JavaBean has a GUI graphical user interface and is visible to the end user. Non-visual JavaBean does not require inheritance. It is more commonly used in JSP. It is usually used to encapsulate business logic, data paging logic, database operations and transaction logic, etc. This can achieve the separation of business logic and front-end programs and improve It improves the readability and maintainability of the code, making the system more robust and flexible. With the development of JSP, JavaBean is more and more used in non-visual fields, and has shown increasing vitality in server-side applications.

JavaBeans can be divided into two types: one is a JavaBean with a user interface (UI, User Interface); the other is a JavaBean without a user interface and is mainly responsible for processing transactions (such as data calculations, database manipulation) . JSP usually accesses the latter JavaBean.

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