How to use reflection to copy properties from Pojo to other Java Beans

By Rene Enriquez | Updated: August 29, 2012

Viewed: 2,412 (+10 pv/w)

Tags: java properties reflection

Sometimes we need copy properties from a Java class to other, we can do it this manually or with our own reflection implementation, but in this case use us reflection for automate it with a utility from apache

Requirements

1. commons-beanutils , you can download from here http://commons.apache.org/beanutils/
2. commons-loging , you can download from here http://commons.apache.org/logging/
3. Eclipse
4. JDK 1.6

2. Hands on

1. Create a “Java Project” in eclipse.
2. Project name: CopyProperties, and click on “Finish” button.
3. Unzip both common-beanutils-xxx.zip and commons-logging-xxx.zip.
4. Add commons-beanutils-xxx.jar and commons-logging-xxx.jar to the classpath of your project.

Create a new class “Person” in the package pojo.from

package pojo.from;

public class Person {

        private String name;
        private int age;

        public String getName() {
                return name;
        }

        public void setName(String name) {
                this.name = name;
        }

        public int getAge() {
                return age;
        }

        public void setAge(int age) {
                this.age = age;
        }

}

Create a class “OthePerson” in pojo.to package with same fields

package pojo.to;

public class OthePerson {

        private String name;
        private int age;

        public String getName() {
                return name;
        }

        public void setName(String name) {
                this.name = name;
        }

        public int getAge() {
                return age;
        }

        public void setAge(int age) {
                this.age = age;
        }
}

3. Testing

Create a test class in pojo.test package with main method, and test commons-beanutils.

package pojo.test;

import org.apache.commons.beanutils.BeanUtils;

import pojo.from.Person;
import pojo.to.OthePerson;

/**
 * Class for test copy properties
 *
 * @author Rene Enriquez
 * @date 23/07/2012
 *
 */
public class Test {

        /**
         * Main method
         *
         * @param args
         */
        public static void main(String[] args) throws Exception {
		Person person = new Person();
		person.setAge(15);
		person.setName("rene");

		OtherPerson othePerson = new OtherPerson();

		System.out.println("*** Before BeanUtils.copyProperties ***");

		System.out.println("Person");
		System.out.println(person.getAge());
		System.out.println(person.getName());

		System.out.println("othePerson");
		System.out.println(othePerson.getAge());
		System.out.println(othePerson.getName());

		//copy properties from (target, source)
		BeanUtils.copyProperties(othePerson, person);

		System.out.println("\n*** After BeanUtils.copyProperties ***");

		System.out.println("Person");
		System.out.println(person.getAge());
		System.out.println(person.getName());

		System.out.println("othePerson");
		System.out.println(othePerson.getAge());
		System.out.println(othePerson.getName());

	}
}

Output

*** Before BeanUtils.copyProperties ***
Person
15
rene
othePerson
0
null

*** After BeanUtils.copyProperties ***
Person
15
rene
othePerson
15
rene

Download Source Code

References

1. commons-beanutils official website
2. commons-logging official website