The technical principles of the Commons Beanutils framework in the Java class library explore
The technical principles of the Commons Beanutils framework in the Java class library explore
introduction:
Commons Beanutils is an open source framework provided by the Apache Software Foundation to process the JavaBean object.In Java development, Beanutils can simplify the attribute copy, attribute assignment, and the conversion of object data.This article will explore the technical principles of the Commons Beanutils framework in the Java library and provide the corresponding Java code example.
1. Introduction to JavaBean
JavaBean is a reusable Java class written in accordance with specific specifications to encapsulate data and provides access to the data.The JavaBean class must have the following characteristics:
1. There must be a non -parameter structure;
2. Privatization of attributes, access and modify the attribute values through the public Getter and Setter methods;
3. Serialized support: Implement the Serializable interface.
The principle of the COMMONS BeANUTILS framework
The Commons Beanutils framework realizes the copying, assignment and conversion of attributes by analyzing the structure and attributes of JavaBean.It mainly includes the following core components:
1. Convertutils (type converter):
ConvertUtils is a type converter component in the Commons Beanutils framework, which is used to convert attribute types during the attribute copying process.Convertutils provides a series of types of type conversion methods, such as string converting to integer, date to string.In the process of attribute copying, if the type of target attribute is inconsistent with the type of origin, Convertutils will automatically transform the type.
2. Propertyutils (attribute tool):
Propertyutils is an important component in the Commons Beanutils framework to operate the attribute of the JavaBean object.Propertyutils provide many methods to obtain, set and copy the attributes of the JavaBean object.With the help of Propertyutils, we can obtain and operate the attributes of JavaBean through the reflection mechanism.
3. Beanutils (Bean Tool):
Beanutils is the core class of the Commons Beanutils framework, which encapsulates a large number of methods to operate JavaBean.Through Beanutils, the operations of attribute copy and attribute assignment between the JavaBean objects can be implemented.The BEANUTILS class completes the copying and type conversion of attributes by calling components such as Propertyutils, Convertutils, and other components.
Example of COMMONS BeANUTILS framework
Now, we will demonstrate the application of the Commons Beanutils framework through an example.
Suppose we have two JavaBean classes: Student and Teacher, which have the following attributes:
public class Student {
private String name;
private int age;
private String grade;
// Getter and Setter method omitted
}
public class Teacher {
private String name;
private int age;
// Getter and Setter method omitted
}
Now, we hope to copy the attribute value of the Student object to the Teacher object.Use Commons Beanutils to easily implement this operation. The example code is as follows:
import org.apache.commons.beanutils.BeanUtils;
public class Main {
public static void main(String[] args) throws Exception {
Student student = new Student();
Student.setname ("Zhang San");
student.setAge(18);
Student.setGrade ("High One");
Teacher teacher = new Teacher();
BeanUtils.copyProperties(teacher, student);
System.out.println ("Teacher Name:" + Teacher.getName ());
System.out.println ("Teacher Age:" + Teacher.getage ());
}
}
Run the above code, the output result is as follows:
Teacher's name: Zhang San
Teacher Age: 18
By using the Beanutils CopyProperties () method, we successfully copy the name and age attribute of the Student object to the Teacher object.
Fourth, conclusion
The technical principles of the Commons Beanutils framework in the Java library are mainly based on the attributes and reflection mechanisms of JavaBean.Using this framework, we can easily perform attribute copying, assignment and type conversion between the JavaBean objects.The framework simplifies the work of developers and improves the reuse and flexibility of the code.
This article introduces the principle of the Commons Beanutils framework and demonstrate its application through an example.By understanding the technical principles of the Commons Beanutils framework, we can better use the framework to improve the efficiency and convenience of Java development.
