The expansion and customization of the Commons Beanutils Core framework in the Java class library
Commons Beanutils Core framework is a very popular Java class library that provides many functions for operating JavaBean.It can help developers to simplify the reading and writing of the attributes of JavaBean, and provide some other functions, such as copying Bean and obtaining Bean's description information.Although Beanutils Core is very powerful and flexible, sometimes developers may need to expand its functions or customize it.This article will expand and customize how to expand and customize the Commons Beanutils Core framework.
1. Expand Beanutils Core framework
If we need to add some custom functions to Beanutils Core, we can implement it by inheriting the relevant classes and covering some methods.The following is an example that demonstrates how to expand Beanutils Core to add a custom method to get all the attribute names of Bean:
import org.apache.commons.beanutils.BeanUtils;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.List;
public class CustomBeanUtils extends BeanUtils {
public static List<String> getPropertyNames(Object bean)
throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
List<String> propertyNames = new ArrayList<>();
java.beans.PropertyDescriptor[] descriptors = getPropertyDescriptors(bean);
for (java.beans.PropertyDescriptor descriptor : descriptors) {
propertyNames.add(descriptor.getName());
}
return propertyNames;
}
}
In the above example, we created a class called Custombeanutils, which inherited the Beanutils class.We added a static method getpropertynames. This method accepts an object bean as a parameter and uses the GetPropertyDescriptors method to get all the attribute descriptors of the Bean.Then, we traversed these attribute descriptors, added the attribute name to a list, and finally returned to this list.
By using the CustomBeanutils class we have customized, we can now easily get all the attribute names of a Bean:
public class Main {
public static void main(String[] args) {
Person person = new Person();
person.setName("John");
person.setAge(30);
try {
List<String> propertyNames = CustomBeanUtils.getPropertyNames(person);
for (String propertyName : propertyNames) {
System.out.println("Property name: " + propertyName);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
In the above example, we created a JavaBean class called Person and set the values of several attributes for it.We then call the GetPropertynames method of CustomBeanutils to get all the attribute names of the Person object and print output.
2. Customized Beanutils Core framework
Sometimes, we want to customize the behavior of the Beanutils Core frame to meet specific needs.We can implement the relevant configuration options.The following is an example that demonstrates how to customize the Beanutils Core framework and ignore the empty attribute when copying bean:
import org.apache.commons.beanutils.BeanUtilsBean;
public class CustomBeanUtilsBean extends BeanUtilsBean {
@Override
public void copyProperty(Object dest, String name, Object value)
throws IllegalAccessException, InvocationTargetException {
if (value == null) {
// If the attribute value is empty, it will not be copied to the target object
return;
}
super.copyProperty(dest, name, value);
}
}
In the above example, we inherited the Beanutilsbean class and covered the CopyProperty method.We add a judgment to the method that if the attribute value is empty, we will not be copied to the target object.In this way, we can ignore the empty attribute when copying bean.
In order to use our customized BeanutilScore framework, we need to set it in the code to implement it as the default Beanutil:
public class Main {
public static void main(String[] args) {
Person source = new Person();
source.setName("John");
source.setAge(30);
Person dest = new Person();
dest.setName("Peter");
try {
CustomBeanUtilsBean customBeanUtilsBean = new CustomBeanUtilsBean();
customBeanUtilsBean.copyProperties(dest, source);
System.out.println("Destination object's name: " + dest.getName());
System.out.println("Destination object's age: " + dest.getAge());
} catch (Exception e) {
e.printStackTrace();
}
}
}
In the above example, we created a JavaBean class called Person and set the values of several attributes for it.Then, we created a target object Dest and set a initial value for its name property.Next, we can copy the attributes of the Source object to the Dest object by creating an instance of Custombeanutilsbean and calling its CopyProperties method.Since the Age property of the Source object is NULL, according to our customized configuration, it will not be copied to the Dest object.Finally, we print the value of the name and Age property of the Dest object.
Through the above examples, we can see how to expand and customize the Commons Beanutils Core framework by inheriting the relevant class and covering the method.Whether it is adding a custom method or the adjustment of the framework, we can flexibly customize the Beanutils Core framework according to specific needs, and operate JavaBean more efficiently in Java development.
