Legacy Code Improvements

Medallia's feedback platform has a legacy servlet endpoint that customer-success reps use to search survey comments by keyword. It hasn't been touched in years and is up for review.

public class CommentSearchServlet extends HttpServlet {

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        String keyword = req.getParameter("keyword");
        Vector results = new Vector();

        try {
            Connection conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASS);
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM comments WHERE text LIKE '%" + keyword + "%'");

            while (rs.next()) {
                results.addElement(rs.getString("text"));
            }
        } catch (Exception e) {}

        PrintWriter out = resp.getWriter();
        for (int i = 0; i < results.size(); i++) {
            out.println((String) results.elementAt(i));
        }
    }
}

Propose enhancements or bug fixes for this snippet of legacy code. What's wrong with it as written, and what would you change before letting it back into production?