How to create a javabean: First create a Web project, create a package in the src directory, and create a public class in the package; then modify the member variables with private to make the member variables private; then add the public class to the Create a parameterless constructor; finally use the getter and setter methods to wrap the member variables.
#This article will introduce how Javabeans are created and what are the rules?
JavaBean is a reusable Java component that can be called by Java applications such as Applet, Servlet, JSP, 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 brand 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.
JavaBean is usually used in Jsp pages. There are two ways to create JavaBean. One is to create a JavaBean instance just like using a normal Java class. You can use the New keyword and then use the constructor method to instantiate a JavaBean instance. The other is to use JavaBean in Jsp pages usually using Jsp action tags. Here we mainly introduce the first creation method.
First create a Web project, because JavaBean is a Java class and is created in the same way as an ordinary Java class. Create a package in the src directory and create a class class in the package.
Four principles of JavaBean:1. Public class 2. No-argument constructor 3. Private member variables 4. Getter and setter methods wrap member variables.
A JavaBean is formed based on these four principles.
Public class: Modify it with public
public class Users { }
Private member variable: Modify the variable with private
public class Users { private String username; private String password; }
In Create a parameterless constructor in the Users class:
public class Users { private String username; private String password; public Users(){} }
The getter and setter methods wrap member variables:
public class Users { private String username; private String password; public Users(){} public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
A JavaBean is created.
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