Question

I had this working before, but then I changed some things, and I can’t get it to work again. I am trying to use my service tier to hit the database and get a correct object from my converter class, depending on what the user clicks. I inject the service property into my converter with spring. During debugging, I can see that the property gets sets properly. But then when I go to call getService, it is null.

@FacesConverter("PlaceConverter")

@SessionScoped
public class PlaceConverter implements Converter {

private SearchQueryService searchQueryService;

/**
 * @return the searchQueryService
 */
public SearchQueryService getSearchQueryService() {
    return searchQueryService;
}

/**
 * @param searchQueryService the searchQueryService to set
 */
public void setSearchQueryService(SearchQueryService searchQueryService) {
    this.searchQueryService = searchQueryService;
}

@Override
public Object getAsObject(FacesContext arg0, UIComponent arg1, String submittedValue) {
        try {
            Criteria criteria = new Criteria();
            criteria.setId(Integer.parseInt(submittedValue));
            return getSearchQueryService().findPlaces(criteria).get(0);
        } catch (NumberFormatException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    return null;
}

@Override
public String getAsString(FacesContext arg0, UIComponent arg1, Object value) {
    ((Place) value).setCategory(" (" + ((Place) value).getCategory() + ")");
    return String.valueOf(((Place) value).getPlaceId());
}

}

<bean id="placeConverterBean" class="com.ghghg.converter.PlaceConverter">
    <property name="searchQueryService" ref="searchQueryServiceBean" />
</bean>

Answer 1

Dependency injection in a converter works only if the converter is declared as a managed bean by the dependency injection framework in question. E.g. JSF’s own @ManagedBean, or CDI’s @Named, or Spring’s @Component. You should remove the @FacesConverter altogether and reference the converter instance in EL scope instead of referencing it by the converter ID.

Thus, so

<h:inputXxx converter="#{placeConverter}" />

or

<f:converter binding="#{placeConverter}" />

instead of

<h:inputXxx converter="PlaceConverter" />

or

<f:converter converterId="PlaceConverter" />

Your concrete problem suggests that you were referencing it by converter ID (thus, via @FacesConverter). This way you end up getting a converter instance without any injected dependencies.

See also:

• How to inject Spring bean into JSF converter

As to the role of the converter itself, this is mandatory because HTML code is represented as one large string and HTTP request parameter values can only be represented as strings. Complex Java objects would otherwise be printed via Object#toString() like so com.example.Place@hashcode, making it unusable in the server side.