Question

我正在为使用JSF的应用程序开发一个评论部分目前我正在将评论传递给数据库，并使用ajax将其呈现在评论输入下方我现在正试图将评论发布的日期存储到数据库中的评论对象。对于注释文本，我将输入框的值分配给注释对象中的相应实体。我编写了一个返回当前日期和时间的方法，当用户添加注释时，我想调用此方法，设置它的值并将其传递给数据库。
这是我目前的代码。我无法弄清楚如何在JSF结束时为这个日期工作。谢谢你的帮助。

JSF页面：

<table>
        <tr>
        <td><div class="white"><H2>Comments</H2></div>
        <h:inputTextarea rows="5" cols="55" id="comment"  class="inputbox" value="#{commentBean.comment.commentText}"
                    size="20" /></td>
                    </tr>
                    <tr>
            <td></td>

            <!-- CODE I NEED TO SET THE DATE AUTOMATICALLY TO commentBean.comment.commentDate -->

            <td><h:commandButton id="update"
                    action="#{commentBean.addComment(searchBean.companyId)}" class="myButton2" value="Add Comment">
                <f:ajax execute="@form" render=":results" />
                </h:commandButton></td>
        </tr>
    </table>

CommentBean：

    public String addComment(int contractorId) {
        factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
        EntityManager em = factory.createEntityManager();   
        em.getTransaction().begin();
        Query myQuery = em.createQuery("SELECT u FROM BusinessAccount u WHERE u.id=:id");
        myQuery.setParameter("id", contractorId);

        List<BusinessAccount> accounts=myQuery.getResultList();
        BusinessAccount account =accounts.get(0);

        comment.setBusinessAccount(account); //managing both sides
        account.getComments().add(comment); //managing both sides
        em.persist(comment);

        em.getTransaction().commit();
        em.close();
        comment.setCommentText(null);

        return "success";
    }


public String calculateCurrentDateTime() {


       DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy HH:mm");     
       //get current date time with Calendar()
       Calendar cal = Calendar.getInstance();
       String currentDate=dateFormat.format(cal.getTime()).toString();


return currentDate;

}

评论对象类：

@Entity
@Table(name = "comments")
public class Comment {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int comment_id;

@Column(name = "comment_text")
private String commentText;

@Column(name = "date")
private String commentdate;


public String getCommentdate() {
    return commentdate;
}

public void setCommentdate(String commentdate) {
    this.commentdate = commentdate;
}

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumns({ @JoinColumn(name = "contractor_id", referencedColumnName="id") })
private BusinessAccount businessAccount;

public BusinessAccount getBusinessAccount() {
    if (businessAccount == null) {
        businessAccount = new BusinessAccount();
    }
    return businessAccount;
}

public void setBusinessAccount(BusinessAccount businessAccount) {
    this.businessAccount = businessAccount;
}

public int getComment_id() {
    return comment_id;
}

public void setComment_id(int comment_id) {
    this.comment_id = comment_id;
}

public String getCommentText() {
    return commentText;
}

public void setCommentText(String commentText) {
    this.commentText = commentText;
}

}

Answer 1

当用户发布新评论时调用addComment(int )，只需在保留评论对象之前调用并同时使用方法calculateCurrentDateTime()，如下所示：

public String addComment(int contractorId) {
    ...
    comment.setCommentdate(calculateCurrentDateTime()); // setting the comment's date property before adding it to the account object and before persisting
    account.getComments().add(comment); //managing both sides
    em.persist(comment);
    ...
}

如何将方法的返回值传递给JSF中的对象？

1 个答案: