Weblogic服务器上的Vaadin applicationContext nullpointer错误答案

【问题标题】：Vaadin applicationContext nullpointer error on weblogic serverWeblogic服务器上的Vaadin applicationContext nullpointer错误
【发布时间】：2017-11-11 02:54:18
【问题描述】：

我的 vaadin 应用程序有问题。该项目在我的本地 tomcat 服务器上成功运行。当我将它部署在 weblogic 服务器中时，出现如下错误。我该如何解决这个问题？

此外，我还有一些用于简单用户指南的嵌入式资源（图像文件）。

DBDefaultValues.java：

private static void addDefaultCompany() {
  ICompanyService companyService = 
     UtilsForSpring.getSingleBeanOfType(ICompanyService.class); //line:34
  if (companyService.getCompanies().size() == 0) {
     Company company = new Company();
     company.setCompanyName("MyComapny");
     companyService.save(company);
  }
}

UtilsForSpring.java：

@Component
public class UtilsForSpring implements ApplicationContextAware {
   private static ApplicationContext context;

   public static <T> T getSingleBeanOfType(Class<T> beanClass) {
       return context.getBeansOfType(beanClass).values().iterator().next();
   }

   @Override
   public void setApplicationContext(ApplicationContext context) throws BeansException {
        UtilsForSpring.context = context;
   }
}

config.xml 文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd">


    <context:component-scan base-package="com.myproject.vaadinapp"/>
    <context:annotation-config/>
    <context:property-placeholder location="classpath:/hibernate.properties"/>
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <mvc:annotation-driven/>


    <task:annotation-driven/>
    <bean id="clearReservedPstnBbk" class="com.myproject.vaadinapp.MainUI"></bean>

    <bean id="dataSource" class="org.springframework.jdbc.datasource.SingleConnectionDataSource">
        <property name="driverClassName" value="${db.driverClassName}"></property>
        <property name="url" value="${db.url}"></property>
        <property name="username" value="${db.username}"/>
        <property name="password" value="${db.password}"/>
        <property name="suppressClose" value="true"/>
    </bean>


    <bean id="hibernateCfgProperties"
          class="org.springframework.beans.factory.config.PropertiesFactoryBean">
        <property name="properties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop> 
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">false</prop>
                <prop key="hibernate.use_sql_comments">true</prop>
                <prop key="hibernate.cache.use_second_level_cache">true</prop>
                <prop key="hibernate.cache.use_query_cache">true</prop>
                <prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.SingletonEhCacheRegionFactory</prop>
                <prop key="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
                <prop key="hibernate.c3p0.testConnectionOnCheckout">true</prop>
                <prop key="hibernate.c3p0.timeout">1800</prop>
                <prop key="hibernate.c3p0.maxIdleTimeExcessConnections">20</prop>
                <prop key="hibernate.c3p0.validate">false</prop>
                <prop key="hibernate.c3p0.idle_test_period">30</prop>
                <prop key="hibernate.c3p0.automaticTestTable">conTestTable</prop>
            </props>
        </property>
    </bean>

    <bean id="sessionFactory"
          class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="hibernateProperties" ref="hibernateCfgProperties"/>
        <property name="packagesToScan" value="com.myproject.vaadinapp.model"/>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>

</beans>

这里是错误：

]] Root cause of ServletException.
com.vaadin.server.ServiceException: java.lang.NullPointerException
    at com.vaadin.server.VaadinService.handleExceptionDuringRequest(VaadinService.java:1474)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1434)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:379)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:844)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:280)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:254)
    at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:136)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:346)
    at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
    at weblogic.websocket.tyrus.TyrusServletFilter.doFilter(TyrusServletFilter.java:205)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3436)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3402)
    at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
    at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
    at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:57)
    at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2285)
    at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2201)
    at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
    at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1572)
    at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:255)
    at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)
Caused By: java.lang.NullPointerException
    at net.egemsoft.ahenk.utils.UtilsForSpring.getSingleBeanOfType(UtilsForSpring.java:17)
    at net.egemsoft.ahenk.utils.DBDefaultValues.addDefaultCompany(DBDefaultValues.java:34)
    at net.egemsoft.ahenk.utils.DBDefaultValues.initialize(DBDefaultValues.java:25)
    at net.egemsoft.ahenk.MainUI.init(MainUI.java:83)
    at com.vaadin.ui.UI.doInit(UI.java:698)
    at com.vaadin.server.communication.UIInitHandler.getBrowserDetailsUI(UIInitHandler.java:214)
    at com.vaadin.server.communication.UIInitHandler.synchronizedHandleRequest(UIInitHandler.java:74)
    at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1422)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:379)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:844)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:280)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:254)
    at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:136)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:346)
    at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
    at weblogic.websocket.tyrus.TyrusServletFilter.doFilter(TyrusServletFilter.java:205)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3436)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3402)
    at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
    at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
    at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:57)
    at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2285)
    at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2201)
    at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
    at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1572)
    at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:255)
    at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)
>

【问题讨论】：

你的 weblogic 版本是多少？
我的版本是12.1.3
你的 setApplicationContext 不应该用@autowired注解吗？
另外，weblogic 的类加载器加载类的顺序可能与 tomcat 不同。您必须确保在 DBDefaultValues 之前构造 UtilsForSpring。尝试在 spring 配置 xml 中定义 UtilsForSpring bean，并确保它是所述 xml 中的第一行。
我添加了自动装配和重新部署，但我仍然遇到同样的错误。

标签： java oracle spring-mvc vaadin7 weblogic12c

【解决方案1】：

很可能，您的 DBDefaultValues bean 是在 UtilsForSpring 之前构建的。您需要强制执行此操作。

更改您的 config.xml 以便 spring 将首先构建您的实用程序 bean。像这样：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="http://www.springframework.org/schema/beans     http://www.springframework.org/schema/beans/spring-beans.xsd     http://www.springframework.org/schema/context     http://www.springframework.org/schema/context/spring-context.xsd       http://www.springframework.org/schema/tx     http://www.springframework.org/schema/tx/spring-tx.xsd     http://www.springframework.org/schema/mvc     http://www.springframework.org/schema/mvc/spring-mvc.xsd     http://www.springframework.org/schema/task     http://www.springframework.org/schema/task/spring-task.xsd">

    <bean class="path.to.UtilsForSpring" />
    <context:component-scan base-package="com.myproject.vaadinapp"/>

您可以像以前一样继续使用注释。

如果上述方法有效，那么您可以继续在 addDefaultCompany 方法上使用 @DependsOn 注释，并从 config.xml 中删除新添加的 bean 定义。

@DependsOn(value = "utilsForSpring")
private static void addDefaultCompany() {
  ICompanyService companyService = 
     UtilsForSpring.getSingleBeanOfType(ICompanyService.class); //line:34
  if (companyService.getCompanies().size() == 0) {
     Company company = new Company();
     company.setCompanyName("MyComapny");
     companyService.save(company);
  }
}

【讨论】：

感谢您的帮助，但我仍然遇到同样的错误。我试图评论所有这些方法并部署了我的应用程序。它部署成功。但是我没有登录应用程序。我认为它可能会发生applicationContext。
项目代码在这里github.com/ekocbiyik/testDataManagementDemo可能是我忘记了什么
可以调试代码吗？那里究竟是什么？ spring 能否成功注入上下文？
所有这些都在我的本地机器上成功运行，一切都很清楚。我认为问题是weblogic。我还发现了类似下面的内容 ------>>>> org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from URL [zip:/app/Middleware/user_projects/domains/ahenk_domain/servers/ahenk_01 /tmp/_WL_user/Ahenk-test-2.0/z8g469/war/WEB-INF/lib/_wl_cls_gen.jar!/hibernate-config.xml]；嵌套异常是 java.lang.ClassCastException：weblogic.xml.jaxp.RegistryDocumentBuilderFactory 不能转换为 javax.xml.parsers.DocumentBuilderFactory
尝试将您的 weblogic.xml 更改为：12.1.3.0.0 falsejavax.xml.* package-name> 我在克隆你的仓库时遇到问题，因为我在公司代理后面。我有时间会调查的

【解决方案2】：

我解决了这个问题！原因是我曾经使用 Vaadin 插件。我尝试了插件的所有版本，但它与 weblogic server 12.1.3 无法正常工作

<dependency>
    <groupId>org.vaadin.addon</groupId>
    <artifactId>jfreechartwrapper</artifactId>
    <version>3.0.0</version>
 </dependency>

【讨论】：