Enabling connection pooling with HSQLDB and Spring embedded database - sql

Question

Recently, I have been trying to implement an in-memory database based on HSQLDB for one of our applications which uses Oracle DB in the production. The application uses spring framework. However, I have to implement the data-source bean programmatically as we are using the existing SQL DDL statements(Oracle queries) and so have to programmatically remove constructs like namespaces before they can run on HSQLDB.
I initialize the database using EmbeddedDatabaseBuilder(ResourceLoader).
Now my issue is that I now want to add connection pooling using say c3p0 to this.
Normally I would be using
<bean id="c3p0DataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="HSQLDB driver path" /> (this is just for representation)
<property name="jdbcUrl" value="${xxx.jdbcUrl}" />
<property name="user" value="${xxx.username}" />
<property name="password" value="${xxx.password}" />
<property name="minPoolSize" value="1" />
<property name="maxPoolSize" value="3" />
<property name="maxIdleTime" value="20" />
</bean>
However, I am confused as to how I can define this while using the Spring embedded database.
Disclaimer: I am really new to spring.

Answer 1

Following this link:
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class C3P0Utils {
public static ComboPooledDataSource newDefaultDS() {
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setMinPoolSize(1);
dataSource.setMaxPoolSize(1);
dataSource.setMaxIdleTime(20);
return dataSource;
}
}
import java.beans.PropertyVetoException;
import java.sql.Driver;
import org.springframework.jdbc.datasource.embedded.ConnectionProperties;
import org.springframework.jdbc.datasource.embedded.DataSourceFactory;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class ComboPoolDataSourceFactory implements DataSourceFactory,
ConnectionProperties {
private final ComboPooledDataSource dataSource;
public ComboPoolDataSourceFactory() {
this(C3P0Utils.newDefaultDS());
}
public ComboPoolDataSourceFactory(ComboPooledDataSource dataSource) {
assert dataSource != null;
this.dataSource = dataSource;
}
public ConnectionProperties getConnectionProperties() {
return this;
}
public ComboPooledDataSource getDataSource() {
return dataSource;
}
public void setUsername(String username) {
dataSource.setUser(username);
}
public void setPassword(String password) {
dataSource.setPassword(password);
}
public void setUrl(String url) {
dataSource.setJdbcUrl(url);
}
public void setDriverClass(Class<? extends Driver> driverClass) {
try {
dataSource.setDriverClass(driverClass.getName());
} catch (PropertyVetoException e) {
e.printStackTrace();
}
}
}
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
public class EmbeddedC3P0DatabaseBuilder extends EmbeddedDatabaseBuilder {
public EmbeddedC3P0DatabaseBuilder() {
setDataSourceFactory(new ComboPoolDataSourceFactory());
}
}
And a short usage example:
EmbeddedC3P0DatabaseBuilder builder = new EmbeddedC3P0DatabaseBuilder();
EmbeddedDatabase db = builder
.setType(EmbeddedDatabaseType.H2)
.addScript("setup-tables.sql")
.build();
JdbcTemplate template = new JdbcTemplate(db);
....
db.shutdown();