Fix for timeout on DBCP connections

Depending on idle connection timeout settings of database server, idle connections in connection pool sometimes timeout.

You can see exception like this if you are using DBCP for your connection pool:

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 7 ms ago.
 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
 at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
 at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
 at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
 at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2985)
 at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2871)
 at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3414)
 at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)
 at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
 at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)
 at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:4874)
 at org.apache.commons.dbcp.DelegatingConnection.setAutoCommit(DelegatingConnection.java:331)
 at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.setAutoCommit(PoolingDataSource.java:317)
 at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:63)
 at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1326)
 at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:558)
 at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:374)
 at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:263)
 at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:101)
 at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
 at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
 at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
 at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
 at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2431)
 at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2882)
 ... 52 more

Simple solution is to make DBCP verify connections before giving them to the caller.
Add the following properties to your BasicDataSource configuration:

       <property name="testOnBorrow" value="true"/>
       <property name="validationQuery" value="SELECT 1"/>