Question

单击命令按钮时，我从DB加载了数据：

<h:commandButton value="Show article content and comments" action="#{dataBean.activateArticleContentView}" actionListener="#{dataBean.loadCurrentArticle}">
<f:attribute name="articleId" value="#{article.id}"></f:attribute>
</h:commandButton>

@ManagedBean
@ViewScoped
public class DataBean implements Serializable {

    ...

    private List<UserAcc> users;
    private List<Article> articles;
    private List<ArticleComment> articleComments;

    private Article currentArticle;

    public void loadComments(ActionEvent e) {
        DataBaseUtil dbu = new DataBaseUtil();
        int articleId = (Integer) e.getComponent().getAttributes()
                .get("articleId");
        articleComments = dbu.loadArticleComments(articleId);
    }

    public void loadCurrentArticle(ActionEvent e) {
        DataBaseUtil dbu = new DataBaseUtil();
        int articleId = (Integer) e.getComponent().getAttributes()
                .get("articleId");
        this.currentArticle = dbu.loadArticleById(articleId);
        this.currentArticle.setComments(dbu.loadArticleComments(articleId));
    }
...

它加载文章及其评论。 textArea和commandButton也在同一页面上呈现，用于添加注释。

<h:inputTextarea value="#{persistenceBean.text}" style="height: 50px; width: 300px">
</h:inputTextarea>
<h:commandButton value="Save" actionListener="#{persistenceBean.saveComment}">
    <f:attribute name="userName" value="#{loginBean.name}"></f:attribute>
    <f:attribute name="articleId" value="#{dataBean.currentArticle.id}"></f:attribute>
</h:commandButton>

命令按钮在另一个bean（PersistenceBean）中激活此方法：

public void saveComment(ActionEvent e){
        int articleId = (Integer) e.getComponent().getAttributes().get("articleId");
        String userName = (String) e.getComponent().getAttributes().get("userName");

        DataBaseUtil dbu = new DataBaseUtil();

        UserAcc user = dbu.loadUserByName(userName);
        ArticleComment comment = new ArticleComment();
        comment.setText(this.text);
        Date postat = new Date();
        comment.setPostat(postat.toString());

        dbu.saveComment(articleId, user.getId(), comment);
    }

我的问题是如何使用注释重新呈现表，以便可以立即显示更改。现在我需要回到文章视图，然后单击显示文章内容和注释的按钮。我可以为添加注释的按钮设置多个动作侦听器，换句话说，如何在添加注释后再次使用dataBean.loadCurrentArticle。

Answer 1

更改

actionListener="#{persistenceBean.saveComment}"

到

actionListener="#{dataBean.saveComment}"

并在PersistenceBean中注入DataBean（我假设是@EJB），以便您可以在DataBean#saveComment()中执行以下操作：

persistenceBean.saveComment(e);
loadCurrentArticle();

无关具体问题，有更优雅的方式来传递JSF 2.x中的属性。另请参阅How can I pass selected row to commandLink inside dataTable?

JSF重新呈现从DB加载的数据

1 个答案: