Are you looking for this piece of code?

// get data base connection
Context ctx = new InitialContext();
DataSource ds = (DataSource) ctx.lookup("java:/MyDS");
conn = ds.getConnection();

// get data base driver
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");

// Execute the select
pstmtSelect = conn.prepareStatement("SELECT * FROM MyTable");
ResultSet rs = pstmtSelect.executeQuery();