java - org.hibernate.AssertionFailure : possible non-threadsafe access to the session

Question

我正在开发一个使用 AngularJs 作为前端、Spring+Hibernate 作为服务层的 Web 应用程序。服务层有一组 AngularJs 使用的 REST API。应用程序的前端没有大问题。但是在服务层，我面临一些并发问题。对于某些情况，我必须从同一个 http session 对同一个 REST API 进行并行异步调用。当我这样做时，有时我会收到上述错误。实际上，错误每次都在变化。有时我也会在 Query.List() 操作上得到 NULLPointerException。有时我得到 TransactionResourceAlreadyClosed 异常。下面附上各种配置和代码片段。

Web.xml

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>WEB-INF/config/fs-cxf-serverContext.xml,WEB-INF/config/fs-spring-jpa-config.xml,WEB-INF/config/security-beans.xml</param-value>
</context-param>

<listener>
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<filter>
    <filter-name>CorsFilter</filter-name>
    <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
    <init-param>
        <param-name>cors.allowed.origins</param-name>
        <param-value>*</param-value>
    </init-param>
    <init-param>
        <param-name>cors.allowed.headers</param-name>
        <param-value>Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-Headers,Access-Control-Allow-Origin</param-value>
    </init-param>
    <init-param>
        <param-name>cors.exposed.headers</param-name>
        <param-value>Access-Control-Allow-Origin</param-value>
    </init-param>
    <init-param>
        <param-name>cors.allowed.methods</param-name>
        <param-value>GET, POST, PUT, DELETE, OPTIONS, HEAD</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>CorsFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<filter>
    <filter-name>springSecurityFilterChain</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
    <filter-name>springSecurityFilterChain</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<servlet>
    <description>Servlet to Initialize and shutdown the Scheduler</description>
    <servlet-name>QuartzInitializer</servlet-name>
    <servlet-class>org.quartz.ee.servlet.QuartzInitializerServlet</servlet-class>
    <init-param>
        <param-name>config-file</param-name>
        <param-value>quartz.properties</param-value>
    </init-param>
    <init-param>
        <param-name>shutdown-on-unload</param-name>
        <param-value>true</param-value>
    </init-param>
    <init-param>
        <param-name>start-scheduler-on-load</param-name>
        <param-value>true</param-value>
    </init-param>
    <load-on-startup>2</load-on-startup>
</servlet>
<servlet>
    <servlet-name>CXFServlet</servlet-name>
    <servlet-class>org.apache.cxf.transport.servlet.CXFServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>CXFServlet</servlet-name>
    <url-pattern>/services/*</url-pattern>
</servlet-mapping>

<resource-ref>
    <res-ref-name>jdbc/foodsafetyDS</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
    <res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>

JPA 配置

<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"
xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.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/task http://www.springframework.org/schema/task/spring-task-3.2.xsd">

<!-- Hibernate session factory -->
<bean id="sessionFactory"
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="configLocation" value="classpath:hibernate.cfg.xml" />
    <property name="entityInterceptor">
        <bean class="com.cts.foodSafety.interceptor.AuditLogInterceptor"/>
    </property>
</bean>

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

<bean id="persistenceAnnotation"
    class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

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

hibernate .cfg.xml

<hibernate-configuration>
<session-factory>
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hibernate.connection.datasource">java:comp/env/jdbc/foodsafetyDS</property>
    <property name="hbm2ddl.auto">update</property>
    <property name="show_sql">false</property>

    <!-- Mapping with model class containing annotations -->

我使用 CXF 创建了一个简单的休息 Controller 。 REST端点如下

@Path("/units")
@Produces(MediaType.APPLICATION_JSON)
public interface UnitService extends Serializable {

@GET
@Path("/getGraphData/{type}")
@Produces(MediaType.APPLICATION_JSON)
public UnitServiceBean getGraphData(@PathParam("type") String type)
        throws FoodSafetyException;

}

Controller 的实现如下

xxxServiceImpl.java

@Service("unit")
@Transactional
public class xxxServiceImpl implements xxxService {

private static final long serialVersionUID = 1L;

@Autowired
xxxDelegate xxxDelegate;

@Override
public UnitServiceBean getGraphData(String type) throws FoodSafetyException {
    UnitServiceBean bean = new UnitServiceBean();

    List<String[]> data = unitDelegate.getGraphData(type);
    ....
    ....
    return bean;
}

代表调用 DAO。 (到目前为止，我们还没有引入 Business 对象)。 DAO的实现如下

@Component
public class UnitDAOImpl extends FoodSafetyDAO implements UnitDAO {
@Override
public List<String[]> getGraphData(String type) {
    List<String[]> data = new ArrayList<String[]>();
    Map<String, List<UnitReadingEntity>> readings = new HashMap<String, List<UnitReadingEntity>>();

    SimpleDateFormat df = CommonConstants.TIME_FORMATTER;

    // Get all the Units
    Query query = getSession().getNamedQuery(
            QueryConstants.FIND_UNITS_BY_TYPE);
    query.setParameter(QueryConstants.TYPE, type);
    List<UnitEntity> units = (List<UnitEntity>) query.list();
    if (units != null && units.size() != 0) {
        .....
        .....

        for (UnitEntity unit : units) {
            Calendar cal1 = Calendar.getInstance();
            cal1.add(Calendar.DAY_OF_YEAR, -1);
            query = getSession().getNamedQuery(
                    QueryConstants.FIND_READING_BY_UNIT_TIME).setLong(
                    QueryConstants.UNIT_ID, unit.getUnitId());

            List<UnitReadingEntity> rr = query.list();
            ...
            ...
        }
    }

    return data;
}

现在，当我使用 POSTMAN 等调用 REST 服务“getGraphData”时，它可以正常工作，没有任何问题。但是，当我使用模拟对这个休息服务的并发调用时，我得到了以下错误

Caused by: org.hibernate.AssertionFailure: possible non-threadsafe access to the session
at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:130)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1108)
at org.hibernate.loader.Loader.processResultSet(Loader.java:964)
at org.hibernate.loader.Loader.doQuery(Loader.java:911)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:342)
at org.hibernate.loader.Loader.doList(Loader.java:2526)
at org.hibernate.loader.Loader.doList(Loader.java:2512)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2342)
at org.hibernate.loader.Loader.list(Loader.java:2337)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:495)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:356)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:195)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1269)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
at com.cts.foodSafety.model.dao.impl.UnitDAOImpl.getGraphData(UnitDAOImpl.java:255)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:51)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:42)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at com.sun.proxy.$Proxy51.getGraphData(Unknown Source)
at com.cts.foodSafety.delegate.UnitDelegate.getGraphData(UnitDelegate.java:39)
at com.cts.foodSafety.delegate.UnitDelegate$$FastClassByCGLIB$$aac35d0d.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:698)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:51)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:42)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:631)
at com.cts.foodSafety.delegate.UnitDelegate$$EnhancerByCGLIB$$75af66.getGraphData(<generated>)
at com.cts.foodSafety.service.impl.UnitServiceImpl.getGraphData(UnitServiceImpl.java:108)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:51)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:42)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:55)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at com.sun.proxy.$Proxy72.getGraphData(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:180)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96)

我用来发出并发请求的客户端如下

public class RestClient implements Runnable{

private String i;

public RestClient(String x) {
    i=x;
}
public static void main(String[] args) {

    for(int i =1;i<=2;i++) {
        Thread t = new Thread(new RestClient(String.valueOf(i)));
        t.start();
    }
}

@Override
public void run() {
    System.out.println("started " + i);
      try {

            URL url = new URL(" http://localhost:8080/fs/services/units/getGraphData/Freezer");
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setRequestProperty("Accept", "application/json");

            if (conn.getResponseCode() != 204) {
                throw new RuntimeException("Failed : HTTP error code : "
                        + conn.getResponseCode());
            }

任何指示/建议？我已经阅读了很多关于 Spring+hibernate 中的 session 和事务管理的 Material 。但我无法解决这个问题。

Answer 1

我认为，如果你像这样使用 Hibernate，那么你应该通过调用 getSession(false) 来获取 session 。相反，以确保您将 session 绑定(bind)到事务。

这在章节Implementing Spring-based DAOs without callbacks in Spring documentation 中有解释。 :此类代码通常将 false 作为 getSession(..) 方法 allowCreate 参数的值传递，以强制在事务中运行(这避免了关闭返回的 Session 的需要，因为它的生命周期由事务管理)。