JSF nested objects set to null on submit

Question

I am facing a similar problem described in this SO thread Why does JSF null out a nested class successfully instantiated in the backing bean? I am having a simple form (JSF-2.2) to create an object with multiple nested objects and their respective properties. Instantiation happens successfully and I can see all objects and their children being not null but for some reason, when I submit the form, the entire object tree is getting set to null again. In the below example, the value template would result in

javax.el.PropertyNotFoundException: Target Unreachable, 'null' returned null.

because for some reason ArticleListConfiguration is being set to null right befor submit happens.

<ui:composition template="../template/template.xhtml">
<ui:define name="content">
    <h:form id="createArticleListForm">
        <p:panel styleClass="content-panel">
            <h:panelGrid
                    columns="2"
                    styleClass="borderless-grid"
                    columnClasses="create-article-list-panel, create-article-list-panel">
                <p:panel
                        id="listValuesPanel">
                    <p:inputText
                            id="articleListName"
                            value="#{createArticleListController.articleList.name}"/>
                    <p:inputText
                            id="articleListSize"
                            maxlength="3"
                            value="#{createArticleListController.articleListSize}">
                    </p:inputText>
                    <p:selectBooleanCheckbox
                            id="saveArticleListConfigurationAsTemplate"
                            value="#{createArticleListController.articleList.articleListConfiguration.template}"/>
                    <h:panelGrid
                            columns="1">
                        <p:fileUpload
                                id="upload"
                                widgetVar="fileUploadWidget"
                                fileUploadListener="#{createArticleListController.uploadImages}"
                                multiple="true"
                                onstart="submitSelection()"
                                oncomplete="handleMultiFileUploadRequest(PF('fileUploadWidget'));"
                                allowTypes="/(\.|\/)(jpg|png)$/"
                                styleClass="ui-widget"/>
                        <p:remoteCommand
                                name="submitSelection"
                                process="@this"/>
                    </h:panelGrid>
                </p:panel>
            </h:panelGrid>
            <br/>
            <p:commandButton
                    id="createArticleListButton"
                    process="@this @form"
                    value="#{contentController.getContent('createArticleList')}"
                    actionListener="#{createArticleListController.onCreate()}"/>
        </p:panel>
    </h:form>
</ui:define>

And here is the backing bean

@ManagedBean
@ViewScoped
public class CreateArticleListController extends AbstractController {

@Inject
private ArticleListService articleListService;

private ArticleList articleList;
private Integer articleListSize;
private List<Pair<String, InputStream>> files;


@PostConstruct
public void init() {
    //The constructor of ArticleList creates and attaches instances of all necessary nested objects
    articleList = new ArticleList();
    files = new ArrayList<>();
}

public void onCreate() throws IOException {
    articleListService.create(articleList, files);
    navigateTo("articleListOverview");
}

public void uploadImages(FileUploadEvent event) {
    try {
        files.add(Pair.of(event.getFile().getFileName(), event.getFile().getInputstream()));
    } catch (IOException e) {
        LOGGER.log(Level.ERROR, "Error uploading files");
        JsfMessageUtils.sendErrorMessageToUser("Error uploading files");
    }
}

public ArticleList getArticleList() {
    return articleList;
}

public void setArticleList(ArticleList articleList) {
    this.articleList = articleList;
}

public Integer getArticleListSize() {
    return articleListSize;
}

}

Answer 1

Setter is missing for

private Integer articleListSize;

and p:inputText cannot find it.

Add

public void setArticleListSize(Integer articleListSize) {
    this.articleListSize = articleListSize;
}

to CreateArticleListController.

Also make sure that ArticleList class and its children classes have all referenced getters and setters defined.

UPDATE:

I've created controller that is working OK with your original xhtml page

//...
import javax.faces.bean.ViewScoped;
//...

@ManagedBean(name = "createArticleListController")
@ViewScoped
public class CreateArticleListController implements Serializable {

    ArticleList articleList;
    private Integer articleListSize;

    @PostConstruct
    public void init() {
        System.out.println("On init controller");
        // initiliazing data
        articleList = new ArticleList();
        articleList.setName("List 1");
        //if you omit following lines, you will get the same exception posted in your question
        ArticleListConfiguration ac = new ArticleListConfiguration();
        ac.setTemplate(false);
        articleList.setArticleListConfiguration(ac);
    }

    public ArticleList getArticleList() {
        return articleList;
    }

    public void setArticleList(ArticleList articleList) {
        this.articleList = articleList;
    }

    public Integer getArticleListSize() {
        return articleListSize;
    }

    public void setArticleListSize(Integer articleListSize) {
        this.articleListSize = articleListSize;
    }

    public void onCreate() throws IOException {
        System.out.printf("On create -> Article name: %s, size: %s, template: %s\r\n", articleList.getName(), articleListSize, articleList.getArticleListConfiguration().isTemplate());
    }

    public void uploadImages(FileUploadEvent event) {
        System.out.println("On upload image " + event.getFile().getFileName());
    }
}

So definitelly there must have been something missing in initialization procedure of ArticleList or some other objects. Run my example controller with your page and check out if it works OK and narrow down your debugging to parts of controller that are not posted in the question.