Question

我正在尝试使用延迟加载开发数据表。通过使用UserService（即简单的DAO）从持久性上下文中正确加载未过滤和过滤的记录。我100％确定问题与正在使用的DAO无关，因为它已成功测试并部署在其他软件包中。

当我尝试插入过滤器时出现错误：过滤的项目集合已正确加载到页面上，但看起来在过程结束时出现问题并抛出NPE。之后，该表不再响应任何命令。

感谢您的帮助！

以下是配置，视图和使用的控制器。

配置

Wildfly 8.2.0
JDK 1.8.0_25
PrimeFaces 5.1

查看（XHTML页面）

<?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:ui="http://xmlns.jcp.org/jsf/facelets"
      xmlns:h="http://xmlns.jcp.org/jsf/html"
      xmlns:p="http://primefaces.org/ui">

    <ui:composition template="/template/template.xhtml">

        <ui:define name="body">
            <h:form id="UserListForm">
                <p:panel header="#{bundle.ListUserTitle}">
                    <p:dataTable id="UserTable" value="#{userController.users}" var="user" lazy="true" rows="25"
                                 paginator="true" rowKey="#{user.id}" selectionMode="single" selection="#{userController.selected}"
                                 paginatorTemplate="{RowsPerPageDropdown} {FirstPageLink} {PreviousPageLink} {CurrentPageReport} {NextPageLink} {LastPageLink}" >

                        <p:column headerText="#{bundle.User_id}" filterBy="#{user.id}">
                           <h:outputText value="#{user.id}"/>
                        </p:column>
                        <p:column headerText="#{bundle.User_nickname}" filterBy="#{user.nickname}">
                           <h:outputText value="#{user.nickname}"/>
                        </p:column>

                    </p:dataTable>
                </p:panel>
            </h:form>

        </ui:define>
    </ui:composition>

</html>

控制器

import java.io.Serializable;
import javax.annotation.PostConstruct;
import javax.inject.Named;
import javax.enterprise.context.SessionScoped;
import javax.inject.Inject;
import javax.transaction.Transactional;

@Named("userController")
@SessionScoped
@Transactional(Transactional.TxType.REQUIRED)
public class UserController implements Serializable {

    @Inject
    private UserService userService;

    private LazyUserDataModel users;
    private User selected;

    @PostConstruct
    public void init() {
        users = new LazyUserDataModel(userService);
    }

    public User getSelected() {
        return selected;
    }

    public void setSelected(User selected) {
        this.selected = selected;
    }

    public LazyUserDataModel getUsers() {
        return users;
    }

    public void setUsers(LazyUserDataModel users) {
        this.users = users;
    }

}

懒惰数据模型

import java.util.List;
import java.util.Map;
import org.primefaces.model.LazyDataModel;
import org.primefaces.model.SortOrder;

public class LazyUserDataModel extends LazyDataModel<User> {

    private List<User> data;
    private final UserService userService;

    public LazyUserDataModel(UserService userService) {
        this.userService = userService;
    }

    @Override
    public User getRowData(String rowKey) {
        Long id = Long.valueOf(rowKey);
        for (User u : data) {
            if (u.getId().equals(id))
                return u;
        }
        return null;
    }

    @Override
    public Object getRowKey(User u) {
        return u.getId();
    }

    @Override
    public List<User> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,Object> filters) {
        UserFilterCorrector.correct(filters);
        UserFilter filter = new UserFilter(filters, first, pageSize);
        FilteredDataModel<User> userDataModel = userService.findFilteredList(filter);
        data = userDataModel.getData();
        this.setRowCount(userDataModel.getCount().intValue());
        return data;
    }
}

异常

11:07:46,348 SEVERE [javax.enterprise.resource.webcontainer.jsf.application] (default task-97) Error Rendering View[/user/List.xhtml]: java.lang.NullPointerException
 at javax.faces.component.StateHolderSaver.<init>(StateHolderSaver.java:96) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponentBase.saveAttachedState(UIComponentBase.java:1746) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.ComponentStateHelper.saveMap(ComponentStateHelper.java:378) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.ComponentStateHelper.saveState(ComponentStateHelper.java:256) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponentBase.saveState(UIComponentBase.java:1552) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIData.saveState(UIData.java:1780) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at org.primefaces.component.datatable.DataTable.saveState(DataTable.java:1520) [primefaces-5.1.jar:5.1]
 at com.sun.faces.application.view.FaceletPartialStateManagementStrategy$3.visit(FaceletPartialStateManagementStrategy.java:482) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at com.sun.faces.component.visit.FullVisitContext.invokeVisitCallback(FullVisitContext.java:151) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at org.primefaces.component.api.UIData.visitTree(UIData.java:692) [primefaces-5.1.jar:5.1]
 at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIForm.visitTree(UIForm.java:371) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at com.sun.faces.application.view.FaceletPartialStateManagementStrategy.saveView(FaceletPartialStateManagementStrategy.java:472) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at com.sun.faces.application.StateManagerImpl.saveView(StateManagerImpl.java:89) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at javax.faces.application.StateManager.getViewState(StateManager.java:593) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at com.sun.faces.context.PartialViewContextImpl.renderState(PartialViewContextImpl.java:483) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:325) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at org.primefaces.context.PrimePartialViewContext.processPartial(PrimePartialViewContext.java:60) [primefaces-5.1.jar:5.1]
 at javax.faces.component.UIViewRoot.encodeChildren(UIViewRoot.java:1004) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:430) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219) [jsf-impl-2.2.8-jbossorg-1.jar:]
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
 at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:61) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
 at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:56) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:63) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
 at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:261) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:247) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:76) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:166) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.server.Connectors.executeRootHandler(Connectors.java:197) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:759) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0_25]
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0_25]
 at java.lang.Thread.run(Thread.java:745) [rt.jar:1.8.0_25]

Answer 1

我通过删除具有null的过滤器值并将其替换为空对象来解决我的问题。您可以将断点放在jsf-api / 2.2.8 / jsf-api-2.2.8-sources.jar！/javax/faces/component/UIComponentBase.java:1746中，看看过滤器映射中的哪个值导致错误然后用空对象替换它或删除它。我希望这会有所帮助。

Answer 2

这必须是jsf api实现中的错误。正如您在答案中描述的那样@bcavlin在源代码中没有足够的空值检查来存储具有映射到空对象的任何键的Map。我在此提交了一个JIRA问题，并在那里的更多部门描述了它，se JAVASERVERFACES-4088

Answer 3

我这样做：

反编译jboss-jsf-api_2.2_spec-2.2.11.jar
使用类javax.faces.components.StateHolderSaver创建一个新的proyect并粘贴反编译的代码。
将jboss-jsf-api_2.2_spec-2.2.11.jar添加为库

Changue代码：

[L]

为：

public StateHolderSaver(FacesContext context, Object toSave){
   this.className=toSave.getClass().getName();

清理并构建
在jboss-jsf-api_2.2_spec-2.2.11.jar中替换已编译的StateHolderSaver
运行服务器并运行正常

将filterBy添加到p：dataTable会导致javax.faces.component.StateHolderSaver上的java.lang.NullPointerException。<init> on postback </init>

3 个答案: