JSF 转换器初始化失败

【问题标题】：JSF converter fails to intializeJSF 转换器初始化失败
【发布时间】：2020-09-13 21:40:43
【问题描述】：

我有一个 facelet 页面，其中有一个 primefaces selectCheckboxMenu，用户可以在其中选择一个或多个会议。

Primefaces 8.0, 
 5.194 #badassfish (build 327)|#]
 <dependency>
            <groupId>org.glassfish</groupId>
            <artifactId>javax.faces</artifactId>
            <version>2.3.9</version>
            <scope>provided</scope>
        </dependency>

我需要创建一个转换器来在对象和字符串之间进行转换。但无论我在做什么，它都不起作用。

我注入用作服务的无状态 EJB 未实例化，或者当 CDI 尝试创建转换器时我收到 NPE：

 Error Rendering View[/conferences.xhtml]
java.lang.NullPointerException
    at com.sun.faces.cdi.CdiUtils.createConverter(CdiUtils.java:102)
    at com.sun.faces.application.applicationimpl.InstanceFactory.createConverter(InstanceFactory.java:481)
    at com.sun.faces.application.ApplicationImpl.createConverter(ApplicationImpl.java:510)
    at javax.faces.application.ApplicationWrapper.createConverter(ApplicationWrapper.java:431)
    at org.primefaces.renderkit.SelectRenderer.findImplicitConverter(SelectRenderer.java:202)
    at org.primefaces.renderkit.SelectRenderer.getOptionAsString(SelectRenderer.java:181)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeOption(SelectCheckboxMenuRenderer.java:143)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeOption(SelectCheckboxMenuRenderer.java:137)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeInputs(SelectCheckboxMenuRenderer.java:128)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeMarkup(SelectCheckboxMenuRenderer.java:93)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeEnd(SelectCheckboxMenuRenderer.java:63)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:595)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1654)
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:152)
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:566)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1647)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:468)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:170)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:102)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:76)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:199)
    at javax.faces.webapp.FacesServlet.executeLifecyle(FacesServlet.java:708)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:451)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1628)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:258)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:755)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:575)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:159)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:371)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:238)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:520)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:217)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:182)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:156)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:218)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:95)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:260)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:177)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:109)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:88)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:53)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:524)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:89)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:94)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:33)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:114)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:569)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:549)
    at java.base/java.lang.Thread.run(Thread.java:834)
|#]
  JSF1073: java.lang.NullPointerException caught during processing of RENDER_RESPONSE 6 : UIComponent-ClientId=, Message=null|#]
  No associated message
java.lang.NullPointerException
    at com.sun.faces.cdi.CdiUtils.createConverter(CdiUtils.java:102)
    at com.sun.faces.application.applicationimpl.InstanceFactory.createConverter(InstanceFactory.java:481)
    at com.sun.faces.application.ApplicationImpl.createConverter(ApplicationImpl.java:510)
    at javax.faces.application.ApplicationWrapper.createConverter(ApplicationWrapper.java:431)
    at org.primefaces.renderkit.SelectRenderer.findImplicitConverter(SelectRenderer.java:202)
    at org.primefaces.renderkit.SelectRenderer.getOptionAsString(SelectRenderer.java:181)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeOption(SelectCheckboxMenuRenderer.java:143)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeOption(SelectCheckboxMenuRenderer.java:137)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeInputs(SelectCheckboxMenuRenderer.java:128)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeMarkup(SelectCheckboxMenuRenderer.java:93)
    at org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenuRenderer.encodeEnd(SelectCheckboxMenuRenderer.java:63)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:595)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1654)
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:152)
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:566)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1647)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:468)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:170)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:102)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:76)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:199)
    at javax.faces.webapp.FacesServlet.executeLifecyle(FacesServlet.java:708)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:451)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1628)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:258)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:755)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:575)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:159)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:371)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:238)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:520)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:217)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:182)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:156)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:218)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:95)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:260)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:177)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:109)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:88)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:53)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:524)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:89)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:94)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:33)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:114)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:569)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:549)
    at java.base/java.lang.Thread.run(Thread.java:834)

请在下面找到我的所有代码。

我的小脸：


<?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://java.sun.com/jsf/html"
      xmlns:p="http://primefaces.org/ui"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:ui="http://java.sun.com/jsf/facelets">

<h:head>
<style type="text/css">
.ui-selectlistbox-listcontainer{
 overflow: initial !important;
}
</style>
</h:head>

<h:body>
    <h2>SelectManyMenu Example</h2>
    <h:form>
        <p:selectCheckboxMenu value="#{conferenceSelectionBean.selectedConferences}"
                           multiple="true"  
                          filter="true" filterMatchMode="contains"
                          style="width:300px;">
            <f:selectItems value="#{conferenceSelectionBean.allConferences}" var="conf"
                           itemLabel="#{conf.title}" itemValue="#{conf}"/>
        </p:selectCheckboxMenu>
        <p:commandButton value="Submit" action="#{conferenceSelectionBean.blabla}" update="selectedEmpPanel"/>

        <h3>Selected Employees:</h3>
        <h:panelGrid id="selectedEmpPanel" columns="1">
            <ui:repeat value="#{conferenceSelectionBean.selectedConferences}" var="conf">
                <h:outputText value="#{conf.id} (#{conf.title}) - #{conf.date}"/>
                <br/>
            </ui:repeat>
        </h:panelGrid>
    </h:form>
</h:body>

</html>

我的会议 bean：

package com.logicbig.example;

public class Conference {
    private String id;
    private String title;
    private String date;

    public Conference(String id, String title, String date) {
        this.id = id;
        this.title = title;
        this.date = date;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }



}

我的转换器

package com.logicbig.example;



import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.convert.FacesConverter;
import javax.inject.Inject;

@FacesConverter(forClass=Conference.class, managed=true)
public class ConferenceConverter implements Converter<Conference> {

    @Inject
    ConferenceService conferenceService;


    public ConferenceConverter() { System.out.println("HOLA 2");
    }


    @Override
    public Conference getAsObject(FacesContext fc, UIComponent comp, String value) {System.out.println("Get as object");
       if(conferenceService == null){
            System.out.println("SERVICE IS NULL");
        }

       return null;
    }

    @Override
    public String getAsString(FacesContext fc, UIComponent comp, Conference value) { System.out.println("Get as String");
        return ((Conference) value).getId();
    }
}

在这种情况下，我收到了开头提到的异常。

另外，我试过这个：

package com.logicbig.example;



import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.convert.FacesConverter;
import javax.inject.Inject;

@FacesConverter(value = "confConverter")
public class ConferenceConverter implements Converter {

    @Inject
    ConferenceService conferenceService;


    public ConferenceConverter() { System.out.println("HOLA 2");
    }


    @Override
    public Object getAsObject(FacesContext fc, UIComponent comp, String value) {System.out.println("Get as object");
       if(conferenceService == null){
            System.out.println("SERVICE IS NULL");
        }

       return null;
    }

    @Override
    public String getAsString(FacesContext fc, UIComponent comp, Object value) { System.out.println("Get as String");
        return ((Conference) value).getId();
    }
}

并在我的 xhtml 中输入链接：

<p:selectCheckboxMenu value="#{conferenceSelectionBean.selectedConferences}"
                           multiple="true"  converter="confConverter"
                          filter="true" filterMatchMode="contains"
                          style="width:300px;">
            <f:selectItems value="#{conferenceSelectionBean.allConferences}" var="conf"
                           itemLabel="#{conf.title}" itemValue="#{conf}"/>
        </p:selectCheckboxMenu>

在这种情况下，注入的 bean 始终为空。

我的后盾

package com.logicbig.example;


import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.faces.view.ViewScoped;
import javax.inject.Inject;

import javax.inject.Named;

@Named
@ViewScoped
public class ConferenceSelectionBean implements Serializable {

    @Inject
    ConferenceService conferenceService;

    private List<Conference> selectedConferences = new ArrayList();
    private List<Conference> allConferences;

    @PostConstruct
    private void init() {
        allConferences = conferenceService.getAllConferences();
    }


    public void blabla(){

        for(Conference c : selectedConferences){
            System.out.println(c.getId() +"  " + c.getTitle()+ "   " + c.getDate());
        }
    }


    public ConferenceService getConferenceService() {
        return conferenceService;
    }

    public void setConferenceService(ConferenceService conferenceService) {
        this.conferenceService = conferenceService;
    }

    public List<Conference> getSelectedConferences() {
        return selectedConferences;
    }

    public void setSelectedConferences(List<Conference> selectedConferences) {
        this.selectedConferences = selectedConferences;
    }

    public List<Conference> getAllConferences() {
        return allConferences;
    }

    public void setAllConferences(List<Conference> allConferences) {
        this.allConferences = allConferences;
    }


}

我的无状态会话 bean

package com.logicbig.example;

import java.util.Arrays;
import java.util.List;
import javax.ejb.Stateless;

@Stateless
public class ConferenceService {

    private final List<Conference> conferences;

    public ConferenceService() {
        conferences = Arrays.asList(
                new Conference("1", "Cool conference 1", "2010-05-10"),
                new Conference("2", "Cool conference 2", "2010-05-10"),
                new Conference("3", "Cool conference 3", "2010-05-10"),
                new Conference("4", "Cool conference 4", "2010-05-10"),
                new Conference("5", "Cool conference 5", "2010-05-10")
        );
    }


      public List<Conference> getAllConferences() {
        return conferences;
    }

    public Conference getConferenceById(String value) {
        return conferences.stream()
                        .filter(e -> e.getId().equals(value))
                        .findAny().orElse(null);
    }

}

和我的配置 bean

package com.logicbig.example;

import javax.enterprise.context.ApplicationScoped;
import javax.faces.annotation.FacesConfig;


@ApplicationScoped
@FacesConfig(version = FacesConfig.Version.JSF_2_3)
public class ConfigurationBean {

    public ConfigurationBean() {
    }

}

编辑：

如果我将转换器的开头更改为：

@FacesConverter(value = "confConverter", managed = true)
public class ConferenceConverter implements Converter<Object> {

EJB 服务的注入按预期工作。

我需要在我的 XHTML 页面中包含以下内容

 <f:converter converterId="confConverter"/>

所以现在它按预期工作，我可以停用 @MangedBean 代码。

【问题讨论】：

  • 你为什么发布一个非常部分的堆栈跟踪？ stackoverflow.com/questions/3988788/…
  • 我现在添加了完整的堆栈跟踪。
  • FacesConverters 中有关于注入的 Q/A，检查了吗？ （iirc 中提到了一些关于 managed="true" 的信息）。请发布您的版本信息，Mojarra 2.3.x 中的 x 以及您的 GlassFish 版本。
  • 我完全按照 BalusC 在“Java EE 8 中 JSF 的权威指南”一书中所描述的那样做。顺便说一句，非常好的书。强烈推荐。我已经更新了我的问题。感谢您抽出宝贵时间回复我的问题。

标签： jsf cdi converters stateless-session-bean


【解决方案1】：

正如您自己已经回答的那样，您需要一个用于非原始数据类型的转换器。

对于丢失通用运行时信息的原始数据类型或通用数据类型，mojarra 中存在回归/错误，这可能已在 2.3.10 中修复。 https://github.com/eclipse-ee4j/mojarra/issues/4500.

枚举

在不使用omnifaces.genericEnumConverter的情况下转换枚举

泛型

创建具体的实现类。

我有一个 DataRange&lt;T extends Comparable&lt;T&gt;&gt; 类 DataRange&lt;Date&gt; 和 p:calendar value="#{cc.attrs.range.start}" mojarra 只检索 Comparable&lt;T&gt; 而不是 日期 在转换阶段。

作为一种解决方法，我使用DataRangeDate 来确保Date 的运行时信息不会丢失。

primefaces 6.19

这主要发生在依赖默认转换器时，例如 p:calendar 或 p:inputNumber。

【讨论】：

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