MaxOpenPreparedStatements limit reached

Question

Hi, I get this exception only for SOME database update in my code after several days of application running. Some of the requests passed, and some of them (the same java code) fail.

java.sql.SQLException: MaxOpenPreparedStatements limit reached
       at org.apache.commons.dbcp.PoolingConnection.prepareStatement(PoolingConnection.java:109)
       at org.apache.commons.dbcp.DelegatingConnection.prepareStatement(DelegatingConnection.java:281)
       at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.prepareStatement(PoolingDataSource.java:313)
       at com.prog.C.f(C.java:967)
       at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
       at java.lang.Thread.run(Thread.java:619)
Caused by: java.util.NoSuchElementException
       at org.apache.commons.pool.impl.GenericKeyedObjectPool.borrowObject(GenericKeyedObjectPool.java:808)
       at org.apache.commons.dbcp.PoolingConnection.prepareStatement(PoolingConnection.java:107)
       ... 15 more

Datasource config:

<bean id="DataSource" class="org.apache.commons.dbcp.BasicDataSource"
          destroy-method="close" lazy-init="true" scope="singleton">
        <property name="driverClassName" value="${jdbc.driver.class}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="poolPreparedStatements" value="true"/>
        <property name="maxOpenPreparedStatements" value="20"/>
    </bean>

There are allways available connections. How can I fix it? Thanks.

Answer 1

This means you probably aren't closing resources properly. You should be doing it in a finally block within the scope of the method that you create them in.