Explore the principle of implementation of the "Object Assign" framework in the Java library
[Explore the principle of implementation of the "Object Assign 'framework in the Java library]
introduction:
In Java development, sometimes we need to copy the attribute value of one object to another to facilitate transmission of data or processing specific business logic.The 'Object Assign' framework in the Java class library provides a convenient way to realize the replication or merger of the object's attributes.This article will take you to explore the principle of implementation of the 'Object Assign' framework and provide relevant Java code examples.
1. What is the 'Object Assign' framework?
'Object assign' refers to a framework provided in the Java class library to copy or merge object attributes. It can easily implement the object attribute copy or merger without manually writing the attribute assignment code.
The implementation principle of 'Object ASSIGN'
To understand the implementation principle of the "Object Assign 'framework, we need to clarify its main characteristics and usage methods.The main features of the 'Object Assign' framework are as follows:
1. Support shallow copy and deep copy: You can select shallow or deep copy according to specific needs.
2. Support attribute filtering: You can specify only copying or merging specific attributes by defining the filtering rules.
3. Support empty value filtering: You can choose whether to copy or merge the empty value attribute.
Based on the above characteristics, the 'Object Assign' framework implements the attribute copy or merge through the following steps:
1. List of attributes of the source object and target object.
2. Filter the attribute list according to the filtering rules, and obtain a list of attributes that need to be copied or merged with attributes.
3. According to the selected copy method (shallow copy or deep copy), the attribute is assigned.
Java code example of 'Object ASSIGN'
Here are a simple Java code example to demonstrate how to use the "Object Assign 'framework to implement the replication of the object attribute:
import java.util.Map;
import java.util.HashMap;
import org.apache.commons.beanutils.BeanUtils;
public class ObjectAssignExample {
public static void main(String[] args) {
// Create source objects
User sourceUser = new User("John", 25);
// Create the target object
User targetUser = new User();
// Use the 'Object Assign' framework to copy the attribute
try {
BeanUtils.copyProperties(targetUser, sourceUser);
} catch (Exception e) {
e.printStackTrace();
}
// The attribute value of the output target object
System.out.println (targetuser.getName ()); // Output: John
System.out.println (targetuser.getage ()); // Output: 25
}
}
// User class
class User {
private String name;
private int age;
public User() {
}
public User(String name, int age) {
this.name = name;
this.age = age;
}
// Getter and Setter method ...
// omit the getter and setter method
}
In the above examples, we realize the attributes of the source object to the target object through the Beanutils.copyProperties () method to the target object.The Apache Commons Beanutill is used here, which is a commonly used Java class library, which provides operating tools for JavaBean.
Summarize:
This article explores the framework from the definition, implementation principles of the 'Object Assign' framework, and the Java code example.It is hoped that through the introduction of this article, readers have a certain understanding of the 'Object Assign' framework and can be flexibly used in actual project development.
