cleanest way to create multiple beans of the same class with different properties

Question

Say I have this properties file:

students.bill.firstname=John
students.bill.lastname=Doe
students.bill.age=20
students.jim.firstname=Jim
students.jim.lastname=Wright
students.jim.age=21
.
.
.

I want an xml bean that contains a map of students that has their firstname as the key.

Object example:

Student.java

public class Student {
    String firstname;
    String lastname;
    Integer age;
}

Classroom.java

public class Classroom {
    Map<String, Student> students;
}

What I am looking for is a way to maybe say, create a student bean from properties students.bill.* and add it to the classroom bean map. Then make one for students.jim.* and add it to the classroom bean map. I am really not wanting to create a bean for each student and go through and put each and every value in them.

Answer 1

Spring already supports that out of the box, since Spring 0.9 (but not many people know about that).

You would need to modify your property file slightly.

student.(class)=your.package.here.Student
student.(abstract)=true

jim.(parent)=student
jim.firstname=Jim
jim.lastname=Wright
jim.age=21
... Other student based definitions here.

Now you can use a BeanFactory together with a PropertiesBeanDefinitionReader

DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
PropertiesBeanDefinitionReader reader = new PropertiesBeanDefinitionReader(bf);
reader.loadBeanDefinitions(new ClassPathResource("students.properties"));
Map<String, Student> students = bf.getBeansOfType(Student.class);

Now if you have a new student just add it to the properties file and reload.