Question

I’m just getting to grips with Tomcat and mySQL using the resource sharing method. Its all working fine, but I don’t think I’m handling the connection right. I’m used to using JDBC direct to MySQL not on Tomcat.

My servlet calls intializeConnection() when it is first run, and never again. But I think that I should actually open and close the connection on each statement? Could someone adjust the code below to show the correct method of handling the connection, I’m a little confused.

public Connection con;

    public void intializeConnection() throws SQLException, NamingException{
        connect();
    }

    public void connect() throws SQLException, NamingException{

        Context initCtx = new InitialContext();
        Context envCtx = (Context) initCtx.lookup("java:comp/env");
        DataSource ds = (DataSource) envCtx.lookup("jdbc/TestDB");
        con = ds.getConnection();               

    } 

    public void excuteStatement(String query) throws SQLException{
        con.createStatement().executeUpdate(query);
    }

    public ResultSet getResultSet(String query) throws SQLException{
        //not yet implemented

    }

My second question is, I don’t know how to return a resultSet this way?

TIA

Answer 1

I think a better design is to use a connection for each request and close it when you’re done. It’ll scale better, in my opinion.

Have a look at the JDBC tutorial. It’ll show you how to get a ResultSet and much more:

http://docs.oracle.com/javase/tutorial/jdbc/basics/