How do I access an object method inside a List?

I am creating a website using jsp. I have a method that returns each row from a JDBC query as an object. Each object is added to a list and returned to the jsp file.

This is the method that returns the list of categories stored in a MySQL database:

public List<Object> getCategories() throws Exception{
    this.catList = new ArrayList<Object>();

    try{
        sql = "SELECT cat_id, cat_name FROM crm_categories";
        prep = conn.prepareStatement(sql);
        rs = prep.executeQuery();
        while(rs.next()){
            cat = new Category();
            cat.setAttributes(rs.getInt("cat_id"), rs.getString("cat_name"));
            this.catList.add(cat);
        }
    } catch(Exception e){
        e.printStackTrace();
    }
    return catList;
}

The Category object looks like this:

@WebServlet("/Category")
public class Category extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private String name;
    private int id;

    public Category() {
        name        = null;
        id          = 0;
    }

    public void setAttributes(int id, String name){
        this.name       = name;
        this.id         = id;
    }

    public String[] getAttributes(){
        String[] attributes = {this.name, String.valueOf(this.id)};
        return attributes;
    }
}

I have attempted to iterate through the list of objects. It prints "test" to the browser 7 times which is the correct number of categories:

dbCon conn          = new dbCon();
List<Object> catList;

// get a list of all categories
catList = conn.getCategories();
for (Object o : catList){
    out.println("test");
}

How do I access each Categories getAttributes method?