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Null pointer exception in con.createStatement(); (Struts 2 using netbeans6.1 and MYSQL)

Hrishikesh Maluskar
Ranch Hand

Joined: Jun 19, 2008
Posts: 115
i am creating a application in struts2 using netbeans 6.1. I have done database connection with MYSQL from netbeans. It also shows connection successful , but gives null pointer exception on this line -> con.createStatement();

Log is as folllows->

java.lang.NullPointerException
at net.roseindia.Login.execute(Login.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:404)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly


SCJP 1.5
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Herman Schelti
Ranch Hand

Joined: Jul 17, 2006
Posts: 387
hi,

then con is null.

how do you initialize this variable con? (post some code)

Herman
Hrishikesh Maluskar
Ranch Hand

Joined: Jun 19, 2008
Posts: 115
i have pasted the code below , it shows null pointer exception on the line indicated as ##.

Herman Schelti
Ranch Hand

Joined: Jul 17, 2006
Posts: 387
hi,

my guess is that

throws a ClassNotFoundException


might be in your log, but it's only 1 line, easy to overlook.

Why not change it into


Good luck!

Herman
PS Please copy/paste from your log if you reply.
Hrishikesh Maluskar
Ranch Hand

Joined: Jun 19, 2008
Posts: 115


for the above code i got the following error in the log...how to get around it

Herman Schelti
Ranch Hand

Joined: Jul 17, 2006
Posts: 387
hi,

if the e.getMessage() does not give enough information, add the class of the exception


It will probably give you a ClassNotFoundException, here's how to solve it:

If you have a connection from Netbeans to your MySQL database, that does not mean that your application can connect to the MySQL database.
You will have to add the mysql driver (the .jar file that it's in) to your webapplication (just put the jar file the lib folder of your webapplication), or add that .jar file to the classpath of your server.

Herman
Hrishikesh Maluskar
Ranch Hand

Joined: Jun 19, 2008
Posts: 115
Thanks herman...now i am able to connect to MYSQL
 
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subject: Null pointer exception in con.createStatement(); (Struts 2 using netbeans6.1 and MYSQL)