Test DataSource.

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

 <%@ page import="javax.naming.*,javax.sql.*,java.sql.*"%>

 <%
	Context ctx = new InitialContext();
	DataSource ds = (DataSource) ctx.lookup("java:comp/env/JNDI");
	try {
		Connection conn = ds.getConnection();
		String sql = "select * from user";
		Statement stm = conn.createStatement();
		ResultSet rs = stm.executeQuery(sql);
		ResultSetMetaData rsmd = rs.getMetaData();
		int cols = rsmd.getColumnCount();
		while (rs.next()) {
			for (int i = 1; i <= cols; i++) {
				String field = (String) (rsmd.getColumnName(i));
				String value = (String) (rs.getString(i));
				out.print(field + "=" + value + ";");
			}
		}
		rs.close();
		stm.close();
		conn.close();
	} catch (Exception e) {
		e.printStackTrace();
		out.println(e);
	}
%>