I need a database connection in Java Web service implemented as a session bean, and I'm not sure if I do it right.
I created a class
public final class SQLUtils {
//.....
private static DataSource m_ds=null;
static
{
try
{
InitialContext ic = new InitialContext();
m_ds = (DataSource) ic.lookup(dbName); //Connection pool and jdbc resource previously created in Glassfish , dbName contains the proper JNDI resource name
}
catch (Exception e)
{
e.printStackTrace();
m_ds = null;
}
}
public static Connection getSQLConnection() throws SQLException
{
return m_ds.getConnection();
}
}
Whenever I need a connection I do
Connection cn = null;
try
{
cn = SQLUtils.getSQLConnection();
// use connection
}
finally
{
if (null != cn)
{
try
{
cn.close();
}
catch (SQLException e)
{
}
}
}
Is it ok to use it this way, or I DataSource must be a member of the bean ?
@Stateless
@WebService
public class TestBean {
private @Resource(name=dbName) DataSource m_ds;
}
I'm sorry if it is a nube question, but I'm pretty new to Java. Thanks in advance.
Apart from the C-style formatting, a few unnecessary lines and a bit poor exception handling, you can just do so.
Here's how I'd do it:
public final class SQLUtil {
private static DataSource dataSource;
// ..
static {
try {
dataSource = (DataSource) new InitialContext().lookup(name);
} catch (NamingException e) {
throw new ExceptionInInitializerError(e);
}
}
public static Connection getConnection() throws SQLException {
return dataSource.getConnection();
}
}
I throw here ExceptionInInitializerError
so that the application will immediately stop so that you don't need to face "unexplainable" NullPointerException
when trying to obtain a connection.