无法加载 com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask。 java.lang.IllegalStateException

Question

我正在使用移动 Web 应用程序，其中我使用 Hibernate 的数据库部分和连接池 c3p0，当我运行中的应用程序时开始它工作正常，但在做了一些交易后，如 select、保存、更新，我收到以下异常，我不知道为什么会发生，

Sep 22, 2015 12:40:06 PM org.apache.catalina.loader.WebappClassLoader loadClass
INFO: Illegal access: this web application instance has been stopped already.  Could not load com.mchange.v2.resourcepool.BasicResourcePoolDestroyResourceTask.  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1562)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    at com.mchange.v2.resourcepool.BasicResourcePool.destroyResource(BasicResourcePool.java:1040)
    at com.mchange.v2.resourcepool.BasicResourcePool.removeResource(BasicResourcePool.java:1507)
    at com.mchange.v2.resourcepool.BasicResourcePool.removeResource(BasicResourcePool.java:1477)
    at com.mchange.v2.resourcepool.BasicResourcePool.cullExpired(BasicResourcePool.java:1565)
    at com.mchange.v2.resourcepool.BasicResourcePool.access00(BasicResourcePool.java:44)
    at com.mchange.v2.resourcepool.BasicResourcePool$CullTask.run(BasicResourcePool.java:2089)
    at java.util.TimerThread.mainLoop(Timer.java:512)
    at java.util.TimerThread.run(Timer.java:462)
Exception in thread "C3P0PooledConnectionPoolManager[identityToken->2sa3m19b1vnwmg61s8v1zi|5363e54]-AdminTaskTimer" java.lang.NoClassDefFoundError: com/mchange/v2/resourcepool/BasicResourcePoolDestroyResourceTask
    at com.mchange.v2.resourcepool.BasicResourcePool.destroyResource(BasicResourcePool.java:1040)
    at com.mchange.v2.resourcepool.BasicResourcePool.removeResource(BasicResourcePool.java:1507)
    at com.mchange.v2.resourcepool.BasicResourcePool.removeResource(BasicResourcePool.java:1477)
    at com.mchange.v2.resourcepool.BasicResourcePool.cullExpired(BasicResourcePool.java:1565)
    at com.mchange.v2.resourcepool.BasicResourcePool.access00(BasicResourcePool.java:44)
    at com.mchange.v2.resourcepool.BasicResourcePool$CullTask.run(BasicResourcePool.java:2089)
    at java.util.TimerThread.mainLoop(Timer.java:512)
    at java.util.TimerThread.run(Timer.java:462)
Caused by: java.lang.ClassNotFoundException: com.mchange.v2.resourcepool.BasicResourcePoolDestroyResourceTask
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    ... 8 more

Hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>
    <!-- Database connection settings -->
    <property name="connection.driver_class">org.postgresql.Driver</property>
    <property name="connection.username">postgres</property>
    <property name="connection.password">admin</property>
    <property name="connection.url">jdbc:postgresql://localhost:5432/db</property>

    <!-- SQL dialect -->
    <property name="dialect">com.bss.util.PostgreSQLDialectCustom</property>

    <!-- Enable Hibernate's automatic session context management -->
    <property name="current_session_context_class">thread</property>

    <!-- Echo all executed SQL to stdout -->
    <property name="show_sql">true</property>

    <!-- Use the C3P0 connection pool provider -->
    <property name="hibernate.c3p0.min_size">5</property>
    <property name="hibernate.c3p0.max_size">20</property>
    <property name="hibernate.c3p0.timeout">300</property>
    <property name="hibernate.c3p0.max_statements">50</property>
    <property name="hibernate.c3p0.idle_test_period">3000</property>

    <mapping class="com.bss.model.TestUser"/>
    <mapping class="com.bss.model.ItappFriendlist"/>
    <mapping class="com.bss.model.ItappFriendlistPK"/>
    <mapping class="com.bss.model.User"/>   
    <mapping class="com.bss.model.UserSession"/>    
  </session-factory>
</hibernate-configuration>

Answer 1

所以，您遇到了 tomcat 热重新部署 ClassLoader 问题。

您应该做两件事：

确保当您的应用程序关闭时，您的 Hibernate SessionFactory 也会得到 close()ed。执行此操作的最佳位置是 ServletContextListener。否则，在热重新部署时，来自现已废弃的应用程序的 c3p0 线程将继续运行。参见 SessionFactory.close()
尝试 here 中描述的设置，以防止对已失效对象的杂散引用 ClassLoader。你可以只添加

<property name="hibernate.c3p0.privilegeSpawnedThreads">true</property>
<property name="hibernate.c3p0.contextClassLoaderSource">library</property>

到您的 c3p0 配置部分。

(p.s。确保您使用的是最新版本的 c3p0。这些设置是新的。)

无法加载 com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask。 java.lang.IllegalStateException

Could not load com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask. java.lang.IllegalStateException

java

hibernate

c3p0