How to convert fields of a Java Object to Properties?

Java Bean Components Java 

To convert fields/values of an object to key/value pair of java.util.Properties, we can use JavaBean component API. The target object should follow JavaBean conventions.

Following code demonstrates how to do that.

public class BeanUtil {

    public static <T> Properties toProperties (T t) throws Exception {

        Class<T> c = (Class<T>) t.getClass();
        BeanInfo beanInfo = Introspector.getBeanInfo(c);
        Properties p = new Properties();

        for (PropertyDescriptor pd : beanInfo.getPropertyDescriptors()) {
            String name = pd.getName();
            Object o = pd.getReadMethod().invoke(t);
            if (o != null)
                p.setProperty(name, o == null ? null : o.toString());
        }
        return p;
    }
}

Let's test above code with an example object:

public class Person {
    private String id;
    private String name;
    private String address;

    public Person (String id, String name, String address) {
        this.id = id;
        this.name = name;
        this.address = address;
    }

    public String getId () {
        return id;
    }

    public void setId (String id) {
        this.id = id;
    }

    public String getName () {
        return name;
    }

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

    public String getAddress () {
        return address;
    }

    public void setAddress (String address) {
        this.address = address;
    }

    @Override
    public boolean equals (Object o) {
        if (this == o)
            return true;
        if (o == null || getClass() != o.getClass())
            return false;

        Person person = (Person) o;

        return id != null ? id.equals(person.id) : person.id == null;
    }

    @Override
    public int hashCode () {
        return id != null ? id.hashCode() : 0;
    }
}

public class Main {

    public static void main (String[] args) throws Exception {
        Person p = new Person("1", "Julia", "Coverdale dr, Dallas");
        Properties properties = BeanUtil.toProperties(p);
        System.out.println(properties);
    }
}

Output

{address=Coverdale dr, Dallas, name=Julia, class=class com.logicbig.example.Person, id=1}

Example Project

Dependencies and Technologies Used:

• JDK 1.8
• Maven 3.3.9