Why is the data source not getting database connection without exception?

Question

experts,
I am trying to config server.xml to get database connection. i am now getting no exception duing the connection, but the returned connection is NULL, why? thanks/ this is my codes:
public synchronized Connection getConnection()
try{
Context ctx = new InitialContext();
if (ctx == null)
throw new Exception("Context is null");
Context initContext = new InitialContext();
Context envContext = (Context)initContext.lookup("java:/comp/env");
DataSource ds = (DataSource)envContext.lookup("test");
Connection conn = ds.getConnection();
}catch(Exception ex)
ex.printStackTrace();
return conn;
}

Answer 1

Remove the first slash after "java:".
Context envContext =(Context)initContext.lookup("java:comp/env");