A ResourcePool could not acquire a resource from its primary factory or source

Question

I'm trying to connect to a database in Java, using jdbcTemplate and I'm gettin the error below. I have Googled for a long time and all solutions I found didn't solve my problem. I tried several different DBs (both SQLServer and MySQL) and none worked.

SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [/promotion-handler-admin] threw exception [Could not open JDBC Connection for transaction; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!] with root cause
com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
    at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)
    at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
    at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
    at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:202)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:371)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:335)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:105)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:622)
    ...

This is my properties file:

app.driverClassName=net.sourceforge.jtds.jdbc.Driver
app.url=jdbc:sqlserver://myUrl:port;databaseName=my_database
app.username=myUsername
app.password=myPassword

webapp/WEB-INF/applicationContext-database.xml:

<beans:bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    destroy-method="close">
    <beans:property name="driverClass" value="${app.driverClassName}" />
    <beans:property name="jdbcUrl"
        value="${app.url}" />
    <beans:property name="user" value="${app.username}" />
    <beans:property name="password" value="${app.password}" />
    <beans:property name="acquireIncrement" value="5" />
    <beans:property name="idleConnectionTestPeriod" value="600" />
    <beans:property name="maxPoolSize" value="10" />
    <beans:property name="maxStatements" value="5" />
    <beans:property name="minPoolSize" value="3" />
    <beans:property name="preferredTestQuery" value="select 1 from DUAL" />
</beans:bean>

<!-- TRANSACTION_MANAGERS -->
<!-- See http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/transaction.html -->

<!-- Default -->
<beans:bean id="transactionManager"
    class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <beans:property name="dataSource" ref="dataSource" />
</beans:bean>

DAO class:

@Repository
public class CampaignDAO {
    private JdbcTemplate jdbcTemplate;

    @Resource(name = "dataSource")
    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }

public List<Campaign> getCampaignList() {
    Long start = System.currentTimeMillis();

    List<Campaign> queryList;

    try {
        queryList = jdbcTemplate.query("SELECT * FROM campaign", new RowMapper<Campaign>() {
            public Campaign mapRow(ResultSet rs, int line) throws SQLException {
                Campaign campaign = new Campaign();
                campaign.setId(rs.getLong("id"));
                campaign.setExtraInfo(rs.getString("extra_info"));
                campaign.setBeginTime(rs.getDate("begin_time"));
                campaign.setEndTime(rs.getDate("end_time"));

                return campaign;

            }
        });
    } finally {
         ...
    }
    return queryList;
}

Answer 1

In my case the problem was related with version mismach between MySQL and mysql-connector-java. After few days of headache I took out my ComboPooledDataSource module in a separate clean project and tried to connect with it to MySQL. However, I got stacktrace (unfortunatly I forgot what exactly were there), with which I understood that the problem is related with versions.

Answer 2

For anyone that finds this question in the future. What I was doing wrong was that I was using the jtds driver and I forgot to add that in the url. So in my properties file what I should have done was:

app.url=jdbc:jtds:sqlserver://myUrl:port;databaseName=my_database

Answer 3

For anyone that finds this question in the future.

This can also be caused by a missing database driver.

In my case I was using the maven-shade-plugin with the minimizeJar option set. This - of course - was throwing away the jtds driver because it is not directly referenced anywhere.

This can be fixed as follows:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>1.6</version>
    <executions>
      <execution>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
        <configuration>
          <minimizeJar>true</minimizeJar>
          <filters>
            <filter>
              <!-- Make sure jtds is included. -->
               <artifact>net.sourceforge.jtds:jtds</artifact>
               <includes>
                   <include>**</include>
               </includes>
            </filter>
            <filter>
              <artifact>*:*</artifact>
              <excludes>
                <exclude>META-INF/*.SF</exclude>
                <exclude>META-INF/*.DSA</exclude>
                <exclude>META-INF/*.RSA</exclude>
                <exclude>META-INF/*.sf</exclude>
                <exclude>META-INF/*.dsa</exclude>
                <exclude>META-INF/*.rsa</exclude>
              </excludes>
            </filter>
          </filters>
        </configuration>
      </execution>
    </executions>
  </plugin>