import java.sql.*;
import javax.naming.*;
import javax.sql.DataSource;
/**
* This example shows how to programmatically get and directly use
* an unpooled DataSource
*/
public final class UseJndiDataSource
{
public static void main(String[] argv)
{
try
{
// let a command line arg specify the name we will
// lookup our DataSource.
String jndiName = argv[0];
// Create an InitialContext, and lookup the DataSource in
// the usual way.
//
// We are using the no-arg version of InitialContext's constructor,
// therefore, the jndi environment must be first set via a jndi.properties
// file, System properties, or by some other means.
InitialContext ctx = new InitialContext();
// acquire the DataSource... this is the only c3p0 specific code here
DataSource ds = (DataSource) ctx.lookup( jndiName );
// get hold of a Connection an do stuff, in the usual way
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
try
{
con = ds.getConnection();
stmt = con.createStatement();
rs = stmt.executeQuery("SELECT * FROM foo");
while (rs.next())
System.out.println( rs.getString(1) );
}
finally
{
// i try to be neurotic about ResourceManagement,
// explicitly closing each resource
// but if you are in the habit of only closing
// parent resources (e.g. the Connection) and
// letting them close their children, all
// c3p0 DataSources will properly deal.
attemptClose(rs);
attemptClose(stmt);
attemptClose(con);
}
}
catch (Exception e)
{ e.printStackTrace(); }
}
static void attemptClose(ResultSet o)
{
try
{ if (o != null) o.close();}
catch (Exception e)
{ e.printStackTrace();}
}
static void attemptClose(Statement o)
{
try
{ if (o != null) o.close();}
catch (Exception e)
{ e.printStackTrace();}
}
static void attemptClose(Connection o)
{
try
{ if (o != null) o.close();}
catch (Exception e)
{ e.printStackTrace();}
}
private UseJndiDataSource()
{}
}