OpenJPA: ClassNotFoundException: ...enhance.InstrumentationFactory 解决

使用OpenJPA+Spring组合，初始化OpenJPA组件时发生如下错误：

29891 jpaOpenJpaPersistenceUnit INFO [http-8080-1] openjpa.Runtime - Starting OpenJPA 1.2.1 32094 jpaOpenJpaPersistenceUnit TRACE [http-8080-1] openjpa.jdbc.SQL - <t 2939216, conn 7291773> executing prepstmnt 5119087 SELECT SEQUENCE_SCHEMA, SEQUENCE_NAME FROM INFORMATION_SCHEMA.SYSTEM_SEQUENCES 32110 jpaOpenJpaPersistenceUnit TRACE [http-8080-1] openjpa.jdbc.SQL - <t 2939216, conn 7291773> [16 ms] spent 32125 jpaOpenJpaPersistenceUnit TRACE [http-8080-1] openjpa.jdbc.SQL - <t 2939216, conn 28358933> executing stmnt 24528146 CREATE TABLE OPENJPA_SEQUENCE_TABLE (ID TINYINT NOT NULL, SEQUENCE_VALUE BIGINT, PRIMARY KEY (ID)) 32125 jpaOpenJpaPersistenceUnit TRACE [http-8080-1] openjpa.jdbc.SQL - <t 2939216, conn 28358933> [0 ms] spent 32125 jpaOpenJpaPersistenceUnit TRACE [http-8080-1] openjpa.jdbc.SQL - <t 2939216, conn 22877561> executing stmnt 13663107 CREATE TABLE t_user (id INTEGER NOT NULL, password VARCHAR(255), username VARCHAR(255), PRIMARY KEY (id)) 32125 jpaOpenJpaPersistenceUnit TRACE [http-8080-1] openjpa.jdbc.SQL - <t 2939216, conn 22877561> [0 ms] spent java.lang.ClassNotFoundException: org.apache.openjpa.enhance.InstrumentationFactory at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:280) at sun.instrument.InstrumentationImpl.loadClassAndCallAgentmain(InstrumentationImpl.java:348)

Spring配置文件如下：

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" p:dataSource-ref="dataSource" p:persistenceUnitName="jpaOpenJpaPersistenceUnit"> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.OpenJpaVendorAdapter" p:showSql="true" p:generateDdl="true" p:database="HSQL" /> </property> <property name="loadTimeWeaver"> <bean class="org.springframework.instrument.classloading.SimpleLoadTimeWeaver"/> </property> </bean>

解决的办法如下：

修改Spring配置：

<property name="loadTimeWeaver">
  <!--
   <bean class="org.springframework.instrument.classloading.SimpleLoadTimeWeaver"/>
   -->
        <bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver"/>
     </property>

 

拷贝spring下spring-agent.jar包至tomcat的lib下，给tomcat服务器启动脚本中追加如下代码：

例如：修改tomcat的bin下startup.bat文件：

......

if exist "%CATALINA_HOME%/bin/catalina.bat" goto okHome
cd ..
set CATALINA_HOME=%cd%

set JAVA_OPTS="-javaagent:%CATALINA_HOME%/lib/spring-agent.jar"

 

cd %CURRENT_DIR%
:gotHome

......

 

如果使用Eclipse等IDE，需要在Eclipse的配置中给Tomcat启动追加javaagent。

例如：MyEclipse中：

至此启动Tomcat访问服务，上述错误解决。