cannot connect servlet cu mssql database_问答_开发者

cannot connect servlet cu mssql database

开发者 https://www.devze.com 2023-01-30 03:02 出处：网络

I`m trying to create an on-line booking application for a restaurant. An html file invokes a servlet. This servlet uses a MSSQL database to keep track of the bookings. The problem is that the servlet

I`m trying to create an on-line booking application for a restaurant. An html file invokes a servlet. This servlet uses a MSSQL database to keep track of the bookings. The problem is that the servlet throws an exception when trying to connect to the database(the getMessage() method returns this: "com.microsoft.jdbc.sqlserver.SQLServerDriver"). I have included msbase.jar, mssqlserver.jar and msutil.jar for the jdbc driver. I have done this way every time I used MSSQL and it always worked Is there something else I need to do to get a servlet to connect to MSSQL?

Here is the servlet`s code:

public class AddReservation extends HttpServlet{
    public void doGet(HttpServletRequest cerere, HttpServletResponse raspuns) 
                throws ServletException, IOException{
     Pr开发者_运维问答intWriter out = raspuns.getWriter();
     String nume,zi,luna,an,data,ora,minute;
    //get parameters from html
     raspuns.setContentType("text/html");
     out.println("<HTML><HEAD></HEAD><BODY>");
     if(nume.equals("")||zi.equals("")||luna.equals("")||an.equals("")||ora.equals("")||minute.equals("")){
         out.println("<H3>NU S-AU COMPLETAT TOATE CAMPURILE</H3>");
     }
     else{
       try{
         Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
         Connection con = DriverManager.getConnection("jdbc:microsoft:sqlserver://LAPTOP-TITI;DatabaseName=Restaurant_Servlet","sa","pass313307");
         Statement st = con.createStatement();
         data = zi+"/"+luna+"/"+an;
         ora = ora +":"+minute;
         ResultSet rs;
         rs = st.executeQuery("select count(*) from Rezervari where Data ='"+data+"' and Ora ='"+ora+"'");
         rs.next();
         int n = rs.getInt(1);
         if(n==2){
             out.println("<H3>NU EXISTA LOCURI LIBERE</H3>");
         }
         else{//add to db
             st.executeUpdate("insert into Rezervari(Nume, Data, Ora) values ('"+nume+"','"+data+"','"+ora+"')");
             out.println("<H3>REZERVARE ADAUGATA</H3>");
         }
            rs.close();
            st.close();
            con.close();
       }
       catch(Exception e){
           out.println("<H3>NU S-A REALIZAT CONEXIUNE LA BAZA DE DATE<br><br>"+
                        e.getMessage()+"</H3>");

       }
     }
     out.println("</BODY></HTML>");
     out.close();
    }
    public void doPost(HttpServletRequest cerere, HttpServletResponse raspuns) 
                throws ServletException, IOException{
      doGet(cerere,raspuns);
    }
}

p.s. I am using apache tomcat server on windows Xp

the getMessage() method returns this: "com.microsoft.jdbc.sqlserver.SQLServerDriver"

First of all, don't print only the exception message. Print the whole exception and the trace to the server logs as well. This give more valuable information.

e.printStackTrace();

The exception message which only contains an full qualified classname is however typical for a ClassNotFoundException. This in turn means that the JDBC driver isn't in the classpath. You need to put the JAR file(s) in /WEB-INF/lib folder of your webapp. This folder is part of the webapp's runtime classpath.

Unrelated to the problem: a servlet is not the right place to output HTML. There the JSP is for. It's actually also not the right place to write DB connectivity code straight in, but that's a whole story apart :)