Question

我有一些JSF页面和一些管理bean。在manage bean中，我创建了一些odel文件并尝试通过JSF填充它。但它没有设置值。但是当我在作品中使用现有的模型对象时很棒。

这是我的JSF代码：

 <h:form>           
            <c:set var="patient" value="#{manageBean.patient}" />
            <p:panel id="panel" header="Patient" style="margin-bottom:10px;">  
                <h:panelGrid columns="2">  
                    <h:outputLabel value="First  name" />  
                    <p:inputText id="firstName" required="true" value="#{patient.firstName}" />  

                    <h:outputLabel value="Family  name" />  
                    <p:inputText id="familyName" required="true" value="#{patient.familyName}" />  

                    <h:outputLabel value="Sex"/>
                    <p:selectOneMenu id="sex" rendered="true" value="#{patient.sex}">
                        <f:selectItem itemLabel="Male" itemValue="male" />  
                        <f:selectItem itemLabel="Female" itemValue="female" />  
                    </p:selectOneMenu>

                    <h:outputLabel value="Birthday date" />  
                    <p:calendar value="#{patient.birthdayDate}" mode="inline" id="birthdayDate"/>  

                    <h:outputLabel value="Nationality"/>
                    <p:selectOneMenu id="nationality" rendered="true" value="#{patient.nationality}">
                        <f:selectItem itemLabel="Russian" itemValue="russian" />  
                        <f:selectItem itemLabel="Ukranian" itemValue="ukranian" />  
                    </p:selectOneMenu>

                    <h:outputLabel value="Adress" />  
                    <p:inputText id="adress" required="true" value="#{patient.adress}" />  

                    <h:outputLabel value="Phone number" />  
                    <p:inputMask id="phoneNumber" required="true" value="#{patient.phoneNumber}" mask="(999) 999-9999"/>
                </h:panelGrid>  
            </p:panel> 
            <p:commandButton value="Save" action="#{manageBean.save}" />  
        </h:form>

还有我的ManageBean：

@ManagedBean(name = "manageBean")
@SessionScoped
public class ManageBean implements Serializable {

    private Patient patient;
    private SessionFactory factory;

    public ManageBean() {
        factory = SessionFactoryWrap.getInstance();
    }

    public Patient getPatient() {
        patient = (Patient) FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get("patient");
        if (patient == null) {
            //patient = new Patient("", "", Sex.male, new Date(), Nationality.ukranian, "", "");
            patient = new Patient();
        }
        return patient;
    }

    public String save() {
        Session session = factory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            session.saveOrUpdate(patient);
            tx.commit();
        } catch (HibernateException ex) {
            if (tx != null) {
                tx.rollback();
            }
            ex.printStackTrace();
        } finally {
            session.close();
        }
        patient=null;
        FacesContext.getCurrentInstance().getExternalContext().getSessionMap().put("patient", null);
        return "go_home";

    }
}

Answer 1

尝试更改：

<c:set var="patient" value="#{manageBean.patient}" />

为：

<ui:param name="patient" value="#{manageBean.patient}" />

通过这种方式，您可以将其放在Facelets变量中，然后您就可以引用它来获取并稍后设置。

然后，将患者对象的初始化放在@PostConstruct带注释的方法中，如下所示：

@PostConstruct
public void init() {
    patient = new Patient(); // this will execute every tyme the bean is initialized
}

然后只需为患者财产使用普通的getter和setter（无自定义代码）。

Answer 2

解决问题的另一种方法是根本不使用任何参数，只是直接将UIInput组件绑定到属性：

<h:form>
    <p:panel id="panel" header="Patient" style="margin-bottom:10px;">
        <h:panelGrid columns="2">
            <h:outputLabel value="First  name" />
            <p:inputText id="firstName" required="true"
                value="#{manageBean.patient.firstName}" />
<!-- rest of JSF/Facelets code... -->
</h:form>

此外，遵循JSF最佳实践，您可以通过两种方式重新定义托管bean（据我所见）：

您不需要拥有@SessionScoped注释来处理ajax请求，也意味着只会调用构造函数（和@PostConstruct方法）一次每次会话。这种情况的最佳选择是@ViewScoped注释。更多信息：Managed Bean Scopes。
您的getter / setter方法中不能有任何业务逻辑，因为它将针对您的JSF代码中的每个#{managedBean.property}执行，更多信息：Why JSF calls getters multiple times。知道了这一点，最好只在bean构造函数或@PostConstruct方法中加载会话数据。

通过这一切，您的托管bean应该如下所示：

@ManagedBean(name = "manageBean")
@ViewScoped
public class ManageBean implements Serializable {

    private Patient patient;
    private SessionFactory factory;

    public ManageBean() {
    }

    @PostConstruct
    public void init() {
        //it would be better to initialize everything here
        factory = SessionFactoryWrap.getInstance();
        patient = (Patient)FacesContext.getCurrentInstance().getExternalContext().
            getSessionMap().get("patient");
        if (patient == null) {
            patient = new Patient();
        }
    }

    public Patient getPatient() {
        return patient;
    }

    public void setPatient(Patient patient) {
        this.patient = patient;
    }

    public String save() {
        Session session = factory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            session.saveOrUpdate(patient);
            tx.commit();
        } catch (HibernateException ex) {
            if (tx != null) {
                tx.rollback();
            }
            ex.printStackTrace();
            //in my opinion, it would be better to show a descriptive message
            //instead of returning to the `go_home` view in case of errors.
        } finally {
            session.close();
        }
        //clumsy code line, no need to have it at all
        //patient = null;
        //Don't set the parameter to null, instead remove it from the session map.
        FacesContext.getCurrentInstance().getExternalContext().
            getSessionMap().remove("patient");
        return "go_home";

    }
}

为什么<p：inputtext>没有填写bean </p：inputtext>中的数据

2 个答案: