Using Spring BeanUtils for Object Property Copying and List Conversion

The article introduces the org.springframework.beans.BeanUtils.copyProperties method as a convenient way to copy property values from a source object to a target object, avoiding manual getter and setter calls.

/**
 * Object property copy
 * Copies properties from source object to target object
 *
 * @param source source object
 * @param target target object
 */
public static void copyProperties(Object source, Object target) {
    try {
        BeanUtils.copyProperties(source, target);
    } catch (BeansException e) {
        LOGGER.error("BeanUtil property copy  failed :BeansException", e);
    } catch (Exception e) {
        LOGGER.error("BeanUtil property copy failed:Exception", e);
    }
}

It then presents a generic method to convert a list of objects of type E to a list of objects of type T using the same property‑copying logic.

/**
 * @param input input collection
 * @param clzz  output collection type
 * @param <E>   input collection element type
 * @param <T>   output collection element type
 * @return converted collection
 */
public static <E, T> List<T> convertList2List(List<E> input, Class<T> clzz) {
    List<T> output = Lists.newArrayList();
    if (CollectionUtils.isNotEmpty(input)) {
        for (E source : input) {
            T target = BeanUtils.instantiate(clzz);
            BeanUtil.copyProperties(source, target);
            output.add(target);
        }
    }
    return output;
}

Example classes User and Employee are defined, where Employee contains an extra dept field. The article shows how to copy an Employee instance to a User instance and how to convert a list of Employee objects to a list of User objects.

public class User {
    private String name;
    private Integer age;
    // getters, setters, toString()
}

public class Employee {
    private String name;
    private Integer age;
    private String dept;
    // constructor, getters, setters, toString()
}

A test class demonstrates the usage:

@RunWith(PowerMockRunner.class)
public class TestUtil {
    @Test
    public void test() {
        Employee ee1 = new Employee("A", 21, "it");
        Employee ee2 = new Employee("B", 23, "account");
        User user = new User();
        BeanUtil.copyProperties(ee1, user);
        System.out.println(user);
        System.out.println("-------------分割线--------------");
        List<User> output = new ArrayList<>();
        List<Employee> source = Arrays.asList(ee1, ee2);
        output = BeanUtil.convertList2List(source, User.class);
        for (User str : output) {
            System.out.println(str);
        }
    }
}

The article concludes with a brief thank‑you note and references to the original blog source.