You also can use java collections to configure your service. In order to see an example, let's open the database-organization-configuration.xml file. This file defines a default user organization (users, groups, memberships/roles) of your portal. They use component-plugins which are explained later. You wil see that object-param is used again.

There are two collections: The first collection is an ArrayList. This ArrayList contains only one value, but there could be more. The only value is an object which defines the field of the NewUserConfig$JoinGroup bean.

The second collection is a HashSet that is a set of strings.

    <component-plugin>

      <name>new.user.event.listener</name>

      <set-method>addListenerPlugin</set-method>

      <type>org.exoplatform.services.organization.impl.NewUserEventListener</type>

      <description>this listener assign group and membership to a new created user</description>

      <init-params>

        <object-param>

          <name>configuration</name>

          <description>description</description>

          <object type="org.exoplatform.services.organization.impl.NewUserConfig">

            <field  name="group">

              <collection type="java.util.ArrayList">

                <value>

                  <object type="org.exoplatform.services.organization.impl.NewUserConfig$JoinGroup">

                    <field  name="groupId"><string>/platform/users</string></field>

                    <field  name="membership"><string>member</string></field>

                  </object>

                </value>               

              </collection>

            </field>

            <field  name="ignoredUser">

              <collection type="java.util.HashSet">

                <value><string>root</string></value>

                <value><string>john</string></value>

                <value><string>marry</string></value>

                <value><string>demo</string></value>

                <value><string>james</string></value>

              </collection>

            </field>

          </object>

        </object-param>

      </init-params>

    </component-plugin>

Let's look at the org.exoplatform.services.organization.impl.NewUserConfig bean:

public class NewUserConfig {

  private List    role;

  private List    group;

  private HashSet ignoredUser;


  ...


  public void setIgnoredUser(String user) {

    ignoredUser.add(user);


  ...


  static public class JoinGroup {

    public String  groupId;

    public String  membership;

  ...

}

You see the values of the HashSet are set one by one by the container, and it's the responsibility of the bean to add these values to its HashSet.

The JoinGroup object is just an inner class and implements a bean of its own. It can be accessed like any other inner class using NewUserConfig.JoinGroup.