初始化EbeanServer时出现NullPointerException

Question

I'm attempting to use EbeanORM to connect to MS SQL Server 2012. In addition, I'm using Spring and the jTDS driver.

I'm getting the following exception when initializing the Spring context:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'ebeanServer' defined in class path resource [spring.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
  at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
  at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
  at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
  at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:753)
  at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:834)
  at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537)
  at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
  at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
  at com.example.cloud.dal.Dal.<clinit>(Dal.java:48)
  ... 43 more
Caused by: java.lang.NullPointerException
  at com.avaje.ebeaninternal.server.changelog.DefaultChangeLogListener.configure(DefaultChangeLogListener.java:62)
  at com.avaje.ebeaninternal.server.core.DefaultServer.configureServerPlugins(DefaultServer.java:257)
  at com.avaje.ebeaninternal.server.core.DefaultServer.<init>(DefaultServer.java:248)
  at com.avaje.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:130)
  at com.avaje.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:45)
  at com.avaje.ebean.EbeanServerFactory.createInternal(EbeanServerFactory.java:108)
  at com.avaje.ebean.EbeanServerFactory.create(EbeanServerFactory.java:67)
  at com.avaje.ebean.springsupport.factory.EbeanServerFactoryBean.afterPropertiesSet(EbeanServerFactoryBean.java:54)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$6.run(AbstractAutowireCapableBeanFactory.java:1627)
  at java.security.AccessController.doPrivileged(Native Method)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1624)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
  ... 55 more

Looking at the code in question , I see this is related to configuration. It appears that an expected properties object is null, and it's not expected to be.

I do see the following error in the logs:

16:39:12.070 [run-main-2] ERROR c.a.ebean.config.PropertyMapLoader - ebean.properties not found

This error is confusing to me. Since I'm using Spring to configure the EbeanServer , it seems like I shouldn't need an ebean.properties (EDIT: adding an empty ebean.properties makes the error go away, but not the exception in question). In fact, at one point this setup was working (I could read/write to the DB). Now it's not, and I'm going crazy trying to figure out what changed.

Here's my spring.xml :

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

  <import resource="classpath:default-ebean-server.xml"/>

  <context:property-placeholder location="classpath:dal.properties" />

  <context:component-scan
    base-package="com.example.dal.service" />

  <context:component-scan
    base-package="com.example.dal.dao" />

  <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    destroy-method="close">
    <property name="driverClass" value="net.sourceforge.jtds.jdbc.Driver" />
    <property name="jdbcUrl" value="${db.jdbc_url}" />
    <property name="user" value="${db.user}" />
    <property name="password" value="${db.password}" />

    <!-- these are C3P0 properties -->
    <property name="initialPoolSize" value="${db.min_pool_size}" />
    <property name="minPoolSize" value="${db.min_pool_size}" />
    <property name="maxPoolSize" value="${db.max_pool_size}" />
    <property name="preferredTestQuery" value="SELECT 1" />
    <property name="idleConnectionTestPeriod" value="300" />
    <property name="connectionCustomizerClassName" value="com.example.dal.IsolationLevelConnectionCustomizer" />
  </bean>

  <tx:annotation-driven transaction-manager="transactionManager"/>

  <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
  </bean>

  <bean id="serverConfig" parent="defaultEbeanServerConfig">
    <property name="name" value="serverConfig"/>
    <property name="packages">
      <list>
        <value>com.example.dal.model</value>
      </list>
    </property>
    <property name="dataSource" ref="dataSource"/>
  </bean>

  <bean id="ebeanServer" class="com.avaje.ebean.springsupport.factory.EbeanServerFactoryBean">
    <property name="serverConfig" ref="serverConfig"/>
  </bean>
</beans>

Possibly relevant details:

• Java 8
• EbeanORM 6.4.1
• Spring 4.1.7.RELEASE
• avaje-ebeanorm-spring 4.5.3
• jTDS 1.3.1

Answer 1

Figured it out myself, finally.

The Short Answer

It appears that a new feature introduced in EbeanORM 6.4.1 breaks something. This is the feature in question: https://github.com/ebean-orm/avaje-ebeanorm/issues/390 .

Downgrading (see below) to 6.3.1 resolves the issue.

The Long Answer

I had been using EbeanORM 6.3.1 when I first got things working. I upgraded to 6.4.1, seeing that it had been released a couple days ago. I noticed that things broke shortly after (no automated tests yet). I downgraded to 6.3.1 again, but this didn't fix things so I assumed it was a red herring.

Unbeknownst to me, SBT/Ivy was evicting 6.3.1 in favour of 6.4.1, even though I was explicitly depending on 6.3.1. avaje-ebeanorm-spring , which I'm also using, depends on avaje-ebeanorm with version specifier [6,7) . So, for some reason, SBT/Ivy decided that 6.4.1 was the best resolution of these two version requirements (WTF.... ).

I figured this out with this excellent plugin: https://github.com/jrudolph/sbt-dependency-graph .

To force SBT to give me 6.3.1, I modified my dependencies to add the exclude :

"org.avaje.ebeanorm" % "avaje-ebeanorm" % "6.3.1",
"org.avaje.ebeanorm" % "avaje-ebeanorm-spring" % "4.5.3" exclude("org.avaje.ebeanorm", "avaje-ebeanorm")