introducing a real connection pool

spring-hibernate4/pom.xml

@@ -24,7 +24,7 @@
 		</dependency>
 
 		<!-- persistence -->
-		
+
 		<dependency>
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-orm</artifactId>
@@ -47,6 +47,12 @@
 			<scope>runtime</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>org.apache.tomcat</groupId>
+			<artifactId>tomcat-dbcp</artifactId>
+			<version>7.0.41</version>
+		</dependency>
+
 		<!-- validation -->
 
 		<dependency>

spring-hibernate4/src/main/java/org/baeldung/spring/PersistenceConfig.java

@@ -4,6 +4,7 @@ import java.util.Properties;
 
 import javax.sql.DataSource;
 
+import org.apache.tomcat.dbcp.dbcp.BasicDataSource;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
@@ -11,7 +12,6 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.PropertySource;
 import org.springframework.core.env.Environment;
 import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
-import org.springframework.jdbc.datasource.DriverManagerDataSource;
 import org.springframework.orm.hibernate4.HibernateTransactionManager;
 import org.springframework.orm.hibernate4.LocalSessionFactoryBean;
 import org.springframework.transaction.annotation.EnableTransactionManagement;
@@ -43,7 +43,7 @@ public class PersistenceConfig {
 
     @Bean
     public DataSource restDataSource() {
-        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        final BasicDataSource dataSource = new BasicDataSource();
         dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
         dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("jdbc.url")));
         dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));

spring-hibernate4/src/main/resources/hibernate4Config.xml

@@ -19,7 +19,7 @@
         </property>
     </bean>
 
-    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
+    <bean id="dataSource" class="org.apache.tomcat.dbcp.dbcp.BasicDataSource">
         <property name="driverClassName" value="${jdbc.driverClassName}" />
         <property name="url" value="${jdbc.url}" />
         <property name="username" value="${jdbc.user}" />