<properties>
            <!-- Configurações específicas do Hibernate -->
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
            <property name="hibernate.hbm2ddl.auto" value="update" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />

            <!-- Propriedades JDBC -->
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/financas" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="123" />

            <property name="connection.provider_class" value="org.hibernate.connection.C3P0ConnectionProvider"/>
            <property name="hibernate.c3p0.min_size" value="10" />
            <property name="hibernate.c3p0.max_size" value="20" />
            <property name="hibernate.c3p0.acquire_increment" value="1" />
            <property name="hibernate.c3p0.idle_test_period" value="3000" />
            <property name="hibernate.c3p0.max_statements" value="50" />
            <property name="hibernate.c3p0.timeout" value="1800" />
        </properties>

EntityManager em = JPAUtil.getEntityManager();

ComboPooledDataSource ds = new ComboPooledDataSource();
System.out.println("Numero de conexoes: " + ds.getMaxPoolSize());