JDBC Connection pooling variable context might not have been initialized

Question

I created a JDBC connection pool (jdbc/WILLIAMSON) in Glassfish server using JNDI in Netbeans, I want to use this in all servlets so instead of writing the following code in every servlet

     InitialContext context = new InitialContext();
        //The JDBC Data source that we just created
        DataSource datasource = (DataSource) 
         context.lookup("jdbc/WILLIAMSON");
         Connection connection = null;
          connection = ds.getConnection();

I created a class DBCONN and tried to call an object of this class in every servlet but getting error "variable context might not have been initialized". See my code is below:

       public final class DBCONN {    
       private static final InitialContext context;
       private static final DataSource datasource;
        static{              
          try {
              context = new InitialContext();
                 datasource=(DataSource) context.lookup("jdbc/WILLIAMSON");
          } catch (NamingException ex) {
              Logger.getLogger(DBCONN.class.getName()).log(Level.SEVERE, 
          null, ex);
          }
    }
   private DBCONN() {
      //  I am confused how to use this method, pls guide me
    }// ERROR HERE VARIABLE context MIGHT NOT HAVE BEEN INITIALIZED

    public static Connection getConnection() throws SQLException {
    return datasource.getConnection();
    }

    }

I'm calling the datasource.getConnection() in servlet HOME.java

       DBCONN datasource = new DBCONN();
        Connection connection = null;
        connection = datasource.getConnection();// I am accessing a static 
       method so warning coming accessing static method getConnection(), how 
        to avoid it???

plz help me in finding the answer of above question ? – Williamson Jun 17 '17 at 06:24 — Williamson, Jun 17 '17 at 06:24

Steve Smith · Answer 1 · 2017-06-15T14:18:13.123

0

Change the line to private static InitialContext context = null;. The compiler is warning you that under certain circumstances, context might not be created.

edited Jun 15 '17 at 14:18

answered Jun 15 '17 at 13:59

Steve Smith

2,244
2
18
22

I modified but getting error inside static block- cannot assign a value to final variable context – Williamson Jun 15 '17 at 14:03
@Williamson Remove the `final` keyword. – Steve Smith Jun 15 '17 at 14:18
I modified , in servlet error coming DBCONN() has private access in DBCONN – Williamson Jun 15 '17 at 14:24
@Williamson Change the `private DBCONN()` to `public DBCONN()`. – Steve Smith Jun 15 '17 at 14:25
here https://stackoverflow.com/questions/7592056/am-i-using-jdbc-connection-pooling its written private so I used.. using public may be some coding leakage – Williamson Jun 15 '17 at 14:28
That code is different. Why have you got `DBCONN datasource = new DBCONN();`? – Steve Smith Jun 15 '17 at 14:31
then how to use object "datasource" of class DBCONN ? – Williamson Jun 15 '17 at 14:35
You can write `DBCONN.getConnection()`. – Steve Smith Jun 15 '17 at 14:36
ok but whats d advantage using class in stead of creating its object ? – Williamson Jun 15 '17 at 14:45

user2902870 · Answer 2 · 2017-06-15T14:22:55.867

-2

static{
context = new InitialContext(); 
try { 
datasource=(DataSource) context.lookup("jdbc/WILLIAMSON");
} catch (NamingException ex) { 
Logger.getLogger(DBCONN.class.getName()).log(Level.SEVERE, null, ex);            }

edited Jun 15 '17 at 14:22

answered Jun 15 '17 at 14:12

user2902870

1
4

1

You should modify your answer to add all details, rather not answer one more time. – N00b Pr0grammer Jun 15 '17 at 14:17
static{ context = new InitialContext(); try { datasource=(DataSource) context.lookup("jdbc/WILLIAMSON"); } catch (NamingException ex) { Logger.getLogger(DBCONN.class.getName()).log(Level.SEVERE, null, ex); } – user2902870 Jun 15 '17 at 14:20
Edit your answer and add necessary details, don't comment here! – N00b Pr0grammer Jun 15 '17 at 14:20
edited my answer, Pls try this. hopefully it would work. Sorry I am newbie here – user2902870 Jun 15 '17 at 14:23

JDBC Connection pooling variable context might not have been initialized

2 Answers2