PrimeFaces 无法从 dataTable 的选定行中获取布尔值

Question

我有 PrimeFaces 3.5、JSF 2.2、Hibernate 4 网络应用程序。

home.xhtml 包含一个带有嵌套数据表的标签视图，用于 3 个实体（用户、计算机、应用程序）和添加/编辑/删除按钮。每个按钮都应该调用一个带有表单和提交/取消按钮的对话框。

问题是当我尝试以与设置相同的方式对其进行编辑时，我无法从 selectedApplication 中正确显示布尔值 (licenseRequired)，我收到以下消息：

/pages/home.xhtml @424,149 value="#{homeBean.selectedApplication.licenseRequired}": Target Unreachable, 'selectedApplication' returned null

如果我删除负责 licenseRequired 字段的代码，一切正常，并且我得到其他选定的值没有任何问题：

这是导致该字段出现 NPE 的对话框形式：

    <p:dialog id="editAppDialog" header="Edit" draggable="true" closable="false" modal="true"
          widgetVar="dlg6" width="600" >

    <h:form id="dlg6form">
        <h:panelGrid id="panel6" columns="3">
            <h:outputLabel for="appName2" value="Name: "/>
            <p:inputText id="appName2" required="true" value="#{homeBean.selectedApplication.appName}" 
                         label="Name">
                <f:validator binding="#{uniqueApplicationValidator}"/>
            </p:inputText>
            <p:message for="appName2"/>

            <h:outputLabel for="vendorName2" value="Vendor: "/>
            <p:inputText id="vendorName2" value="#{homeBean.selectedApplication.vendorName}"
                         label="Vendor" required="true" />
            <p:message for="vendorName2"/>

            <h:outputLabel for="appLicense2" value="Requires license: "/>
            <p:selectOneMenu id="appLicense2" required="true" style="width: 80px;" value="#{homeBean.selectedApplication.licenseRequired}" >
                <f:selectItem itemLabel="true" itemValue="#{true}" />
                <f:selectItem itemLabel="false" itemValue="#{false}" />
            </p:selectOneMenu>
            <p:message for="appLicense2"/>


        </h:panelGrid>

        <p:commandButton type="button" value="Cancel" onclick="dlg6.hide()" />

        <p:commandButton value="OK" process="@form" update=":dlg6form:panel6, :tab:applications" action="#{homeBean.editApplication}"
                         oncomplete="if (args &amp;&amp; !args.validationFailed) dlg6.hide()"/>
    </h:form>

</p:dialog>

Application.java：

@Entity
@Table(name="applications", catalog="adminportal")
public class Application  implements Serializable {

    @Id @GeneratedValue(strategy=IDENTITY)
    @Column(name="app_id", unique=true, nullable=false)
     private Integer appId;

    @Column(name="app_name", nullable=false)
     private String appName;

    @Column(name="vendor_name", nullable=false)
     private String vendorName;

    @Column(name="license_required", nullable=false, columnDefinition = "BIT", length = 1)
     private boolean licenseRequired;

    @OneToMany(fetch=FetchType.LAZY, mappedBy="applications")
     private Set<ComputerApp> computerApps = new HashSet<>(0);


    public Integer getAppId() {
        return appId;
    }

    public void setAppId(Integer appId) {
        this.appId = appId;
    }

    public String getAppName() {
        return appName;
    }

    public void setAppName(String appName) {
        this.appName = appName;
    }

    public String getVendorName() {
        return vendorName;
    }

    public void setVendorName(String vendorName) {
        this.vendorName = vendorName;
    }

    public Set<ComputerApp> getComputerApps() {
        return computerApps;
    }

    public void setComputerApps(Set<ComputerApp> computerApps) {
        this.computerApps = computerApps;
    }

    public boolean isLicenseRequired() {
        return licenseRequired;
    }

    public void setLicenseRequired(boolean licenseRequired) {
        this.licenseRequired = licenseRequired;
    }

}

HomeBean.java：

package com.infostroy.adminportal.controller.bean;

import com.infostroy.adminportal.bean.BaseBean;
import com.infostroy.adminportal.model.Application;
import com.infostroy.adminportal.model.Computer;
import com.infostroy.adminportal.model.User;
import java.io.IOException;
import java.security.NoSuchAlgorithmException;
import java.util.List;
import javax.annotation.PostConstruct;
import org.primefaces.context.RequestContext;
import org.primefaces.event.SelectEvent;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

@Component
@Scope("session")
public class HomeBean extends BaseBean {

    private static final String editUserBtn = "tab:form1:editUser";
    private static final String deleteUserBtn = "tab:form1:deleteUser";
    private static final String editCompBtn = "tab:form2:editComp";
    private static final String deleteCompBtn = "tab:form2:deleteComp";
    private static final String editAppBtn = "tab:form3:editApp";
    private static final String deleteAppBtn = "tab:form3:deleteApp";

    private List<User> users;
    private List<Computer> computers;
    private List<Application> applications;
    private User selectedUser, newUser;
    private Computer selectedComputer, newComputer;
    private Application selectedApplication, newApplication;
    private String deleteUserMsg, deleteCompMsg, deleteAppMsg;
    private RequestContext rc;

    @PostConstruct
    public void init() {
        setUsers(hibernateDBManager.getAllUsers());
        setComputers(hibernateDBManager.getAllComputers());
        setApplications(hibernateDBManager.getAllApplications());
        newUser = new User();
        newComputer = new Computer();
        newApplication = new Application();
        rc = RequestContext.getCurrentInstance();
    }

    public void addUser() throws NoSuchAlgorithmException {
        if (hibernateDBManager.insertUser(newUser)) {
            users.add(newUser);
            newUser = new User();
            updateUserButtons();
        }
    }

    public void editUser() throws NoSuchAlgorithmException {
        if (hibernateDBManager.updateUser(selectedUser)) {
            users.set(users.indexOf(selectedUser), selectedUser);
            selectedUser = null;
            updateUserButtons();
        }
    }

    public void deleteUser() throws IOException {
        if (selectedUser != null) {
            if (hibernateDBManager.deleteUserById(selectedUser.getUserId()) > 0) {
                users.remove(selectedUser);
                selectedUser = null;
                updateUserButtons();
            }
        }
    }

    public void addComputer() {
        if (newComputer != null && hibernateDBManager.insertComputer(newComputer)) {
            computers.add(newComputer);
            newComputer = new Computer();
            updateCompButtons();
        }
    }

    public void editComputer() {
        if (hibernateDBManager.updateComputer(selectedComputer)) {
            computers.set(computers.indexOf(selectedComputer), selectedComputer);
            selectedComputer = null;
            updateCompButtons();
        }
    }

    public void deleteComputer() {
        if (selectedComputer != null) {
            if (hibernateDBManager.deleteComputerById(selectedComputer.getComputerId()) > 0) {
                computers.remove(selectedComputer);
                selectedComputer = null;
                updateCompButtons();
            }
        }
    }

    public void addApplication() {
        if (newApplication != null && hibernateDBManager.insertApplication(newApplication)) {
            applications.add(newApplication);
            newApplication = new Application();
            updateAppButtons();
        }
    }

    public void editApplication() {
        if (hibernateDBManager.updateApplication(selectedApplication)) {
            applications.set(applications.indexOf(selectedApplication), selectedApplication);
            selectedApplication = null;
            updateAppButtons();
        } 
    }

    public void deleteApplication() {
        if (selectedApplication != null) {
            if (hibernateDBManager.deleteApplicationById(selectedApplication.getAppId()) > 0) {
                applications.remove(selectedApplication);
                selectedApplication = null;
                updateAppButtons();
            }
        }
    }

    public void onUserRowSelect(SelectEvent event) {
        setSelectedUser((User) event.getObject());
        setDeleteUserMsg("Are you sure you want to delete user "
                + selectedUser.getFirstName() + " " + selectedUser.getLastName() + "?");
    }

    public void onCompRowSelect(SelectEvent event) {
        setSelectedComputer((Computer) event.getObject());
        deleteCompMsg = "Are you sure you want to delete computer "
                + selectedComputer.getComputerName()
                + " (" + selectedComputer.getIpAddress() + ") ?";
    }

    public void onAppRowSelect(SelectEvent event) {
        setSelectedApplication((Application) event.getObject());
        deleteAppMsg = "Are you sure you want to delete application "
                + selectedApplication.getAppName() + "?";
    }

    protected void updateUserButtons() {
        rc.update(editUserBtn);
        rc.update(deleteUserBtn);
    }

    protected void updateCompButtons() {
        rc.update(editCompBtn);
        rc.update(deleteCompBtn);
    }

    protected void updateAppButtons() {
        rc.update(editAppBtn);
        rc.update(deleteAppBtn);
    }

    public String getDeleteUserMsg() {
        return deleteUserMsg;
    }

    public void setDeleteUserMsg(String deleteUserMsg) {
        this.deleteUserMsg = deleteUserMsg;
    }

    public String getDeleteCompMsg() {
        return deleteCompMsg;
    }

    public void setDeleteCompMsg(String deleteCompMsg) {
        this.deleteCompMsg = deleteCompMsg;
    }

    public String getDeleteAppMsg() {
        return deleteAppMsg;
    }

    public void setDeleteAppMsg(String deleteAppMsg) {
        this.deleteAppMsg = deleteAppMsg;
    }
    //Other getters/setters

}

我需要做的是制作一个 selectBoolean/selectOneMenu 或类似的东西，它只能从 2 个选项（真/假）中进行选择。就像在 users 表（角色字段）上一样，设置为当前 selectedUser 的角色：

如果我替换

                <p:selectOneMenu id="appLicense2" required="true" style="width: 80px;" value="#{homeBean.selectedApplication.licenseRequired}" >
                <f:selectItem itemLabel="true" itemValue="#{true}" />
                <f:selectItem itemLabel="false" itemValue="#{false}" />
            </p:selectOneMenu>

用简单的

<p:inputText id="appLicense2" value="#{homeBean.selectedApplication.licenseRequired}"/>

然后一切正常，我显示了正确的值。但这不适合，因为我只需要从 2 个允许的值中进行选择，而不是输入随机文本。

任何想法如何解决这个问题？每一个答案都非常感谢！

谢谢。

Answer 1

只是一个假设，但可能是布尔空值转换错误。

尝试初始化变量，如下所示：

@Column(name="license_required", nullable=false, columnDefinition = "BIT", length = 1)
private boolean licenseRequired = false;