Research on the technical principles of the Commons Beanutils Core framework in the Java class library
The Commons Beanutils Core framework is the next powerful and easy to use Java class library for the Apache Commons project to simplify the attribute copy and conversion operation between the JavaBean objects.This article will explore the technical principles of this framework, including its main core functions and working principles.
1. Core function:
The Commons Beanutils Core framework provides a series of tool methods to simplify the attribute copy and conversion operation between the JavaBean objects.The main functions include:
-The attribute copy: Allow the value of the attribute between different JavaBean objects.By using the Beanutils.copyproperties () method, the attribute values of the source object can be copied into the target object.
-The dynamic creation object: You can create a JavaBean object by using the Beanutils.instantial () method.
-The attribute analysis: You can use the Beanutils.GetProperty () method to obtain the attribute value of the JavaBean object, and set the attribute value with the Beanutils.setProperty () method.
-Ne type conversion: Support automatic conversion between different types, including simple data types, dates, and collection types.
2. Working principle:
The working principle of the Commons Beanutils Core framework is mainly based on Java's reflection mechanism.During the attribute copy and conversion process, it uses the reflection of Java to obtain and set the attribute value.
The specific workflow is as follows:
-The source objects and target objects are passed to Beanutils.copyProperties () method.
-The framework uses the Java's reflection mechanism to obtain the attribute list of the source object.
-S For each attribute, the framework uses reflexes to obtain the attribute value of the source object according to the attribute name.
-The framework sets the attribute value to the corresponding attributes of the target object.
-If the attribute type does not match, the framework will try to use the type converter for automatic type conversion.
-In the end, the target object will have the same attribute values as the source object.
The following is an example code that demonstrates the use of the Commons Beanutils Core:
class User {
private String name;
private int age;
// omit the getter and setter method ...
}
public class Main {
public static void main(String[] args) {
User source = new User();
source.setName("John");
source.setAge(30);
User target = new User();
try {
BeanUtils.copyProperties(target, source);
System.out.println("Name: " + target.getName());
System.out.println("Age: " + target.getAge());
} catch (Exception e) {
e.printStackTrace();
}
}
}
The above code creates a User class, which contains two attributes: name and Age.The property of the source object source is copied to the target target.Finally, we print the attribute value of the target object.
Through this example, we can see the simplicity and powerfulness of the Commons Beanutils Core framework.There is no need to manually write the logic of the attribute copy and conversion. Just call the method provided by the framework to complete the relevant operation.
Summarize:
Commons Beanutils Core framework provides convenient and efficient attribute copy and conversion tools by using the Java's reflection mechanism.It simplifies the data operation between the JavaBean object and reduces the workload of the developer.Whether it is object attribute copy, dynamic creation object or attribute analysis, the Beanutils Core framework provides a simple and easy -to -use method.
