Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThrea

Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2"

Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2" java.lang.OutOfMemoryError: PermGen space
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
	at java.lang.Class.getMethod0(Class.java:2670)
	at java.lang.Class.getMethod0(Class.java:2679)
	at java.lang.Class.getMethod(Class.java:1603)
	at com.mchange.v2.c3p0.impl.C3P0ImplUtils.supportsMethod(C3P0ImplUtils.java:309)
	at com.mchange.v2.c3p0.impl.NewPooledConnection.<init>(NewPooledConnection.java:104)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:198)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
	at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
	at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
该怎么解决:以下是Spring配置文件的数据库连接池
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" >  
        <property name="driverClass" value="oracle.jdbc.driver.OracleDriver" />
		<property name="jdbcUrl" value="jdbc:oracle:thin:@127.0.0.1:1521:ahzt" />
		<property name="user" value="admin" />
		<property name="password" value="123456" />
		<property name="autoCommitOnClose" value="true"/>
		<property name="checkoutTimeout" value="5000"/>
		<property name="initialPoolSize" value="3"/>
		<property name="minPoolSize" value="1"/>
		<property name="maxPoolSize" value="300"/>
		<property name="maxIdleTime" value="60"/>
		<property name="acquireIncrement" value="3"/>
		<property name="maxIdleTimeExcessConnections" value="1800"/>
    </bean>

java.lang.OutOfMemoryError: PermGen space 
表示你的内存永久保存区溢出了。

PermGen space的全称是Permanent Generation space,是指内存的永久保存区域, 
这块内存主要是被JVM存放Class和Meta信息的,Class在被Loader时就会被放到PermGen space中, 
它和存放类实例(Instance)的Heap区域不同,GC(Garbage Collection)不会在主程序运行期对 
PermGen space进行清理，所以如果你的应用中有很多CLASS的话,就很可能出现PermGen space错误, 
这种错误常见在web服务器对JSP进行pre compile的时候。如果你的WEB APP下都用了大量的第三方jar, 其大小 
超过了jvm默认的大小(4M)那么就会产生此错误信息了。 
解决方法： 手动设置MaxPermSize大小 

修改TOMCAT_HOME/bin/catalina.sh 
在“echo "Using CATALINA_BASE:   $CATALINA_BASE"”上面加入以下行： 
JAVA_OPTS="-server -XX:PermSize=64M -XX:MaxPermSize=128m 

根据硬件配置或实际需要，这些设置的内存大小可以再提高一些。