Question

In a swing GUI application, where MVC pattern is applied, how can we use Spring to wire the model view and controller? i.e. what beans (model, view or controller) should be injected using spring and what should be created from the application? I have applied the MVC pattern described here when developing the application. Thanks in advance.

Answer 1

I defined all the beans in spring and used a factory method to create the views when required. Controller is injected to the view and the model and view are added to the controller via spring.

Following are the code samples from a simple example that I came up with, in order to find a solution: (sorry for the long post!)

the application context file:

<bean id="firstModel" class="com.model.FirstModel"></bean>
<bean id="secondModel" class="com.model.SecondModel"></bean>

<bean id="firstController" class="com.controller.FirstController" />
<bean
    class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="targetObject">
        <ref local="firstController" />
    </property>
    <property name="targetMethod">
        <value>addModel</value>
    </property>
    <property name="arguments">
        <list>
            <value>FIRST</value>
            <ref local="firstModel" />
        </list>
    </property>
</bean>
<bean id="secondController" class="com.controller.SecondController" />
<bean
    class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="targetObject">
        <ref local="secondController" />
    </property>
    <property name="targetMethod">
        <value>addModel</value>
    </property>
    <property name="arguments">
        <list>
            <value>SECOND</value>
            <ref local="secondModel" />
        </list>
    </property>
</bean>
<bean
    class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="targetObject">
        <ref local="secondController" />
    </property>
    <property name="targetMethod">
        <value>addModel</value>
    </property>
    <property name="arguments">
        <list>
            <value>FIRST</value>
            <ref local="firstModel" />
        </list>
    </property>
</bean>
<bean id="firstForm" class="com.view.FirstForm">
    <property name="controller">
        <ref bean="firstController" />
    </property>
</bean>
<bean id="secondForm" class="com.view.SecondForm">
    <property name="controller">
        <ref bean="secondController" />
    </property>
</bean>

following is the abstract controller class:

public class AbstractController implements PropertyChangeListener {

Map<Type, BaseView> registeredViews;
Map<Type, AbstractModel> registeredModels;

public AbstractController() {
    registeredViews = new HashMap<Type, BaseView>();
    registeredModels = new HashMap<Type, AbstractModel>();
}

public void addModel(Type type, AbstractModel model) {
    registeredModels.put(type, model);
    model.addPropertyChangeListener(this);
}

public void removeModel(AbstractModel model) {
    registeredModels.remove(model);
    model.removePropertyChangeListener(this);
}

public void addView(BaseView view, Type type) {
    registeredViews.put(type, view);
}

public void removeView(javax.swing.JFrame view) {
    registeredViews.remove(view);
}

public void propertyChange(PropertyChangeEvent evt) {

    for (BaseView view : registeredViews.values()) {
        view.modelPropertyChange(evt);
    }
}

protected void setModelProperty(String propertyName, Object newValue) {
    for (AbstractModel model : registeredModels.values()) {
        Statement statment = new Statement(model, "set" + propertyName, new Object[] { newValue });
        try {
            statment.execute();
        } catch (NoSuchMethodException e) {
            continue;
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}    
}

following is the abstract model class:

public class AbstractModel {

protected PropertyChangeSupport propertyChangeSupport;

public AbstractModel() {
    propertyChangeSupport = new PropertyChangeSupport(this);
}

public void addPropertyChangeListener(PropertyChangeListener listener) {
    propertyChangeSupport.addPropertyChangeListener(listener);
}

public void removePropertyChangeListener(PropertyChangeListener listener) {
    propertyChangeSupport.removePropertyChangeListener(listener);
}

protected void firePropertyChange(String propertyName, Object oldValue, Object newValue) {
    propertyChangeSupport.firePropertyChange(propertyName, oldValue, newValue);
}    
}

Following is the code sample of the view interface:

public interface BaseView {

void modelPropertyChange(PropertyChangeEvent evt);

public abstract void showForm();

}

following is the code sample of the factory class:

public class FormFactory {

private ApplicationContext context;
private static FormFactory viewFactory;

private FormFactory() {
    if (context == null) {
        context = new ClassPathXmlApplicationContext("ApplicationContext.xml");
    }
}

public static synchronized FormFactory getInstance() {
    if (viewFactory == null) {
        viewFactory = new FormFactory();
    }
    return viewFactory;

}

public BaseView createForm(Type type) {
    BaseView form = null;
    switch (type) {
        case FIRST:
            form = (BaseView) context.getBean("firstForm");
            break;
        case SECOND:
            form  = (BaseView) context.getBean("secondForm");
            break;
        default:
            break;
    }
    return form;

}
}