Question

我在部署Login.xhtml时遇到了问题。即使我使用userManagerBean.userName和userManagerBean.passWord来存储用户输入的值，我仍然为我的userName和passWord值获取空值。

任何帮助？

我的代码如下。

谢谢！：）

Login.xhtml

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://xmlns.jcp.org/jsf/html"
      xmlns:f="http://xmlns.jcp.org/jsf/core"
      xmlns:p="http://primefaces.org/ui">
    <h:head>
        <title>Facelet Title</title>
    </h:head>
    <h:body>
        <h:form>
            <h:outputText value="Username: " />
            <p:inputText value="#{userManagerBean.userName}" />
            <br></br>
            <h:outputText value="Password: " />
            <p:password value="#{userManagerBean.passWord}" />
            <br></br>
            <p:commandButton value="Login" id="ajax">
             <p:ajax update="status" listener="#{userManagerBean.loginResult()}" />
            </p:commandButton>
            <br></br>
            <h:outputText id="status" value="#{userManagerBean.loginStatus}" />
        </h:form>
    </h:body>
</html>

UserManagerBean.java

package managedbean;

import javax.ejb.EJB;
import javax.enterprise.context.RequestScoped;
import javax.faces.event.ActionEvent;
import javax.inject.Named;
import session.stateless.SystemUserSession;

@Named(value = "userManagerBean")
@RequestScoped
public class UserManagerBean {

    @EJB
    private SystemUserSession systemUser;
    private String userName;
    private String passWord;
    private String eventNameLength;
    private String loginStatus;


    /**
     * @return the userName
     */
    public String getUserName() {
        return userName;
    }

    /**
     * @param userName the userName to set
     */
    public void setUserName(String userName) {
        this.userName = userName;
    }

    /**
     * @return the passWord
     */
    public String getPassWord() {
        return passWord;
    }

    /**
     * @param passWord the passWord to set
     */
    public void setPassWord(String passWord) {
        this.passWord = passWord;
    }

    /**
     * @return the eventNameLength
     */
    public String getEventNameLength() {
        return eventNameLength;
    }

    /**
     * @param eventNameLength the eventNameLength to set
     */
    public void setEventNameLength(String eventNameLength) {
        this.eventNameLength = eventNameLength;
    }

    public void buttonAction(ActionEvent actionEvent) {
         System.out.println("Welcome to Primefaces!!");
    }


  public String loginResult()
  {
      System.out.println(userName +" "+passWord);
     if(systemUser.getSystemUser(userName,passWord) == null)
     {
         System.out.println("No user found");
         System.out.println(userName +" "+passWord);
         loginStatus = "No user found";
          return "No user found";
     }
     else
     {
         System.out.println("Successful login");
         loginStatus = "Successful login";
          return "Successful login";
     }

  }

    /**
     * @return the loginStatus
     */
    public String getLoginStatus() {
        return loginStatus;
    }

    /**
     * @param loginStatus the loginStatus to set
     */
    public void setLoginStatus(String loginStatus) {
        this.loginStatus = loginStatus;
    }
}

SystemUserSession.java

package session.stateless;

import entity.SystemUser;
import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

@Stateless
@LocalBean
public class SystemUserSession {

    @PersistenceContext
    private EntityManager entityManager;


    public SystemUser getSystemUser(String userName, String passWord) {
        Query query = entityManager.createQuery("SELECT u FROM SystemUser u WHERE u.userName = :inUserName AND u.password = :inPassWord");
        query.setParameter("inUserName", userName);
        query.setParameter("inPassWord", passWord);
        SystemUser systemUser = null;
        try {
            systemUser = (SystemUser) query.getSingleResult();
        } catch (NoResultException ex) {
            //ex.printStackTrace();
        }
        return systemUser;
    }
}

Answer 1

p:ajax默认处理@this，这意味着inputText的值永远不会在bean上更新。

此外，p:commandButton本身具有ajax功能，甚至默认为process="@form"，这就是你想要的。

所以只需将按钮更改为

即可

<p:commandButton value="Login" 
                 id="ajax" 
                 actionListener="#{userManagerBean.loginResult()}" 
                 update="status">
</p:commandButton>

此外我会制作bean @SessionScoped，因为你需要记住整个会话的loginStatus。

JSF托管bean值返回null

1 个答案: