JSF View scope in Spring - spring

Question

Is there any scope like JSF #ViewScoped in Spring 3.0? I have an application using JSF+Spring where backing beans are managed by Spring. I didn't find any scope like JSF wiew scope in Spring. I saw the blog Porting JSF 2.0’s ViewScope to Spring 3.0, but it didn't work for me.
Here's my attempt on the custom Spring scope:
import java.util.Map;
import javax.faces.context.FacesContext;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.beans.factory.config.Scope;
/**
* Implements the JSF View Scope for use by Spring. This class is registered as a Spring bean with the CustomScopeConfigurer.
*/
public class ViewScope implements Scope {
public Object get(String name, ObjectFactory<?> objectFactory) {
System.out.println("**************************************************");
System.out.println("-------------------- Getting objects For View Scope ----------");
System.out.println("**************************************************");
if (FacesContext.getCurrentInstance().getViewRoot() != null) {
Map<String, Object> viewMap = FacesContext.getCurrentInstance().getViewRoot().getViewMap();
if (viewMap.containsKey(name)) {
return viewMap.get(name);
} else {
Object object = objectFactory.getObject();
viewMap.put(name, object);
return object;
}
} else {
return null;
}
}
public Object remove(String name) {
System.out.println("**************************************************");
System.out.println("-------------------- View Scope object Removed ----------");
System.out.println("**************************************************");
if (FacesContext.getCurrentInstance().getViewRoot() != null) {
return FacesContext.getCurrentInstance().getViewRoot().getViewMap().remove(name);
} else {
return null;
}
}
public void registerDestructionCallback(String name, Runnable callback) {
// Do nothing
}
public Object resolveContextualObject(String key) { return null;
}
public String getConversationId() {
return null;
}
}
application-context.xml:
<bean class="org.springframework.beans.factory.config.CustomScopeConfigurer">
<property name="scopes">
<map>
<entry key="view">
<bean class="com.delta.beans.ViewScope"/>
</entry>
</map>
</property>
</bean>

Answer 1

Recently I've created maven artifact which will solve this problem.
See my github javaplugs/spring-jsf repository.

Answer 2

I did something like this without Porting bean to Spring. It's working for me.
#ManagedBean(name="bean")
#ViewScoped // actual jsf viewscoped only with javax.faces.viewscoped import
public class Bean implements
Serializable {
#ManagedProperty(value="#{appService}") // Spring Manged Bean and singleton
private transient AppService appService;
// Getting AppService Object which is singleton in the application during deserialization
private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
stream.defaultReadObject();
FacesContext context = FacesContext.getCurrentInstance();
appService = (AppService)context.getApplication()
.evaluateExpressionGet(context, "#{appService}", AppService.class);
}
}

Answer 3

public class ViewScopeCallbackRegistrer implements ViewMapListener {
#SuppressWarnings("unchecked")
#Override
public void processEvent(SystemEvent event) throws AbortProcessingException {
if (event instanceof PostConstructViewMapEvent) {
PostConstructViewMapEvent viewMapEvent = (PostConstructViewMapEvent) event;
UIViewRoot viewRoot = (UIViewRoot) viewMapEvent.getComponent();
viewRoot.getViewMap().put(
ViewScope.VIEW_SCOPE_CALLBACKS,
new HashMap<String, Runnable>()
);
} else if (event instanceof PreDestroyViewMapEvent) {
PreDestroyViewMapEvent viewMapEvent = (PreDestroyViewMapEvent) event;
UIViewRoot viewRoot = (UIViewRoot) viewMapEvent.getComponent();
Map<String, Runnable> callbacks = (Map<String, Runnable>) viewRoot
.getViewMap().get(ViewScope.VIEW_SCOPE_CALLBACKS);
if (callbacks != null) {
for (Runnable c : callbacks.values()) {
c.run();
}
callbacks.clear();
}
}
}
#Override
public boolean isListenerForSource(Object source) {
return source instanceof UIViewRoot;
}
}

Answer 4

public class ViewScope implements Scope {
public static final String VIEW_SCOPE_CALLBACKS = "viewScope.callbacks";
#Override
public synchronized Object get(String name, ObjectFactory<?> objectFactory) {
Object instance = this.getViewMap().get(name);
if(instance == null){
instance = objectFactory.getObject();
this.getViewMap().put(name, instance);
}
return instance;
}
#SuppressWarnings("unchecked")
#Override
public Object remove(String name) {
Object instance = this.getViewMap().remove(name);
if(instance == null){
Map<String, Runnable> callbacks = (Map<String, Runnable>) this.getViewMap().get(VIEW_SCOPE_CALLBACKS);
if(callbacks != null)
callbacks.remove(name);
}
return instance;
}
/**
* Responsável por registrar uma chamada de destruição ao bean
* que será armazenadano [b]viewMap[/b] da [b]ViewRoot[/b](nossa página que será mostrada)
* #see #getViewMap()
* #param name - nome do bean
* #param runnable
*/
#SuppressWarnings("unchecked")
#Override
public void registerDestructionCallback(String name, Runnable runnable) {
Map<String, Runnable> callbacks = (Map<String, Runnable>) this.getViewMap().get(VIEW_SCOPE_CALLBACKS);
if(callbacks != null)
callbacks.put(name, runnable);
}
#Override
public Object resolveContextualObject(String key) {
FacesContext facesContext = FacesContext.getCurrentInstance();
FacesRequestAttributes facesResquestAttributes = new FacesRequestAttributes(facesContext);
return facesResquestAttributes.resolveReference(key);
}
#Override
public String getConversationId() {
FacesContext facesContext = FacesContext.getCurrentInstance();
FacesRequestAttributes facesResquestAttributes = new FacesRequestAttributes(facesContext);
return facesResquestAttributes.getSessionId() + "-" + facesContext.getViewRoot().getViewId();
}
private Map<String, Object> getViewMap(){
return FacesContext.getCurrentInstance().getViewRoot().getViewMap();
}
}

Answer 5

I have tried a work around for the Jsf view bean memory leak issue for both Jsf 2.1 & Jsf 2.2. Try the code in following link Memory leak with ViewScoped bean?. It will clear the view bean in session while navigating to next page.