Jsf 将filterBy添加到p:dataTable会导致javax.faces.component.StateHolderSaver中的java.lang.NullPointerException；初始化>；回邮

我正在尝试开发一个延迟加载的数据表。 通过使用UserService（即一个简单的DAO），从持久性上下文正确加载未筛选和筛选的记录。 我100%确信这个问题与正在使用的DAO无关，因为它已经在其他包中成功测试和部署

当我尝试插入一个过滤器时，错误就出现了：过滤项的集合被正确地加载到页面上，但看起来在流程结束时出现了一些错误，并抛出了一个NPE。此后，表不再响应任何命令

谢谢你的帮助

在下文中，将介绍所使用的配置、视图和控制器

配置

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]

• Wildfly 8.2.0
• JDK 1.8.0_25
• PrimeFaces 5.1

查看（XHTML页面）

惰性数据模型

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;
    }
}

import java.util.List；
导入java.util.Map；
导入org.primefaces.model.LazyDataModel；
导入org.primefaces.model.SortOrder；
公共类LazyUserDataModel扩展了LazyDataModel{
私人名单数据；
专用最终用户服务用户服务；
公共LazyUserDataModel（用户服务用户服务）{
this.userService=userService；
}
@凌驾
公共用户getRowData（字符串rowKey）{
Long id=Long.valueOf（rowKey）；
用于（用户u：数据）{
如果（u.getId（）.equals（id））
返回u；
}
返回null；
}
@凌驾
公共对象getRowKey（用户u）{
返回u.getId（）；
}
@凌驾
公共列表加载（int-first、int-pageSize、字符串排序字段、排序器排序器、映射过滤器）{
UserFilterCorrector.correct（过滤器）；
UserFilter=newuserfilter（filters，first，pageSize）；
FilteredDataModel userDataModel=userService.findFilteredList（过滤器）；
data=userDataModel.getData（）；
this.setRowCount（userDataModel.getCount（）.intValue（））；
返回数据；
}
}

例外情况

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]

11:07:46348严重[javax.enterprise.resource.webcontainer.jsf.application]（默认任务-97）错误呈现视图[/user/List.xhtml]：java.lang.NullPointerException
位于javax.faces.component.StateHolderSaver.（StateHolderSaver.java:96）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponentBase.saveAttachedState（UIComponentBase.java:1746）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.ComponentStateHelper.saveMap（ComponentStateHelper.java:378）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
位于javax.faces.component.ComponentStateHelper.saveState（ComponentStateHelper.java:256）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponentBase.saveState（UIComponentBase.java:1552）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIData.saveState（UIData.java:1780）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在org.primefaces.component.datatable.datatable.saveState（datatable.java:1520）[primefaces-5.1.jar:5.1]
访问com.sun.faces.application.view.FaceletPartialStateManagementStrategy$3.visit（FaceletPartialStateManagementStrategy.java:482）[jsf-impl-2.2.8-jbossorg-1.jar:]
在com.sun.faces.component.visit.FullVisitContext.invokeVisitCallback（FullVisitContext.java:151）[jsf-impl-2.2.8-jbossorg-1.jar:]
在org.primefaces.component.api.UIData.visitTree（UIData.java:692）[primefaces-5.1.jar:5.1]
在javax.faces.component.UIComponent.visitTree（UIComponent.java:1700）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponent.visitTree（UIComponent.java:1700）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIForm.visitTree（UIForm.java:371）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponent.visitTree（UIComponent.java:1700）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponent.visitTree（UIComponent.java:1700）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponent.visitTree（UIComponent.java:1700）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponent.visitTree（UIComponent.java:1700）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在com.sun.faces.application.view.FaceletPartialStateManagementStrategy.saveView（FaceletPartialStateManagementStrategy.java:472）[jsf-impl-2.2.8-jbossorg-1.jar:]
在com.sun.faces.application.StateManagerImpl.saveView（StateManagerImpl.java:89）[jsf-impl-2.2.8-jbossorg-1.jar:]
在javax.faces.application.StateManager.getViewState（StateManager.java:593）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在com.sun.faces.context.PartialViewContextImpl.renderState（PartialViewContextImpl.java:483）[jsf-impl-2.2.8-jbossorg-1.jar:]
在com.sun.faces.context.PartialViewContextImpl.processPartial（PartialViewContextImpl.java:325）[jsf-impl-2.2.8-jbossorg-1.jar:]
在org.primefaces.context.PrimePartialViewContext.processPartial（PrimePartialViewContext.java:60）[primefaces-5.1.jar:5.1]
位于javax.faces.component.UIViewRoot.encodeChildren（UIViewRoot.java:1004）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在javax.faces.component.UIComponent.encodeAll（UIComponent.java:1856）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView（FaceletViewHandlingStrategy.java:430）[jsf-impl-2.2.8-jbossorg-1.jar:]
在com.sun.faces.application.view.MultiViewHandler.renderView（MultiViewHandler.java:133）[jsf-impl-2.2.8-jbossorg-1.jar:]
位于javax.faces.application.ViewHandlerWrapper.renderView（ViewHandlerWrapper.java:337）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
位于javax.faces.application.ViewHandlerWrapper.renderView（ViewHandlerWrapper.java:337）[jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
在com.sun.faces.lifecycle.RenderResponsePhase.execute（RenderResponsePhase.java:120）[jsf-impl-2.2.8-jbossorg-1.jar:]
在
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]

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

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