Обсуждение: Trouble With JDBC
Hi, I am trying to test out the postgres-JDBC driver. I have a file called sample.java. It compiles fine, but when I run it I get the following error: Exception in thread "main" java.lang.NoClassDefFoundError: sample/java This is what my classpath is set to: export CLASSPATH=.:/usr/local/java_pkgs/jdk1.1.8/lib/postgresql.jar:$CLASSPATH Anyone have any idea as to what is wrong? It looks as if it can't find the sample.class file, but it does exist in the current directory. Thanks Corey Mosher ----------------------------- Hub.Org Networking Services 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@hub.org Phone: (902) 542-3657 ----------------------------- PostgreSQL, Inc. 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@pgsql.com Phone: (902) 542-0713 ----------------------------- Fax: (902) 542-5386
Quoting Corey Mosher <corey@pgsql.com>: > Hi, > > I am trying to test out the postgres-JDBC driver. I have a > file called sample.java. It compiles fine, but when I run it > I get the following error: > > Exception in thread "main" java.lang.NoClassDefFoundError: sample/java > > This is what my classpath is set to: > > export > CLASSPATH=.:/usr/local/java_pkgs/jdk1.1.8/lib/postgresql.jar:$CLASSPATH > > Anyone have any idea as to what is wrong? It looks as if it can't find > the > sample.class file, but it does exist in the current directory. Erm, you are not including .class in the java line are you? eg: java sample.class? If so, drop the .class. It's looking for a file sample/class.class not sample.class ;-) Peter -- Peter Mount peter@retep.org.uk PostgreSQL JDBC Driver: http://www.retep.org.uk/postgres/ RetepPDF PDF library for Java: http://www.retep.org.uk/pdf/
> > Exception in thread "main" java.lang.NoClassDefFoundError: sample/java [snip] > Erm, you are not including .class in the java line are you? > > eg: java sample.class? *cough* You mean sample.java Answer is the same though, just use: java sample </pointless reiteration> Michael Stephenson mstephenson@openworld.co.uk Developer - Web Applications - Open World Tel: +44 1225 444 950 Fax: +44 1225 336 738
On Fri, 16 Feb 2001, Corey Mosher wrote: > Hi, > > I am trying to test out the postgres-JDBC driver. I have a > file called sample.java. It compiles fine, but when I run it > I get the following error: > > Exception in thread "main" java.lang.NoClassDefFoundError: sample/java > > This is what my classpath is set to: > > export CLASSPATH=.:/usr/local/java_pkgs/jdk1.1.8/lib/postgresql.jar:$CLASSPATH > > Anyone have any idea as to what is wrong? It looks as if it can't > find the sample.class file, but it does exist in the current > directory. You might want to start with an introductory book on Java. It looks as if you've included the source code filename extension in your command-line invocation of the program. Drop the ".java" and see what happens. -- Bob Kline mailto:bkline@rksystems.com http://www.rksystems.com
No, to run the program I am using: java sample To compile it I am using: javac sample.java I have had other simple programs running (the usual hello world apps) and they seem to work fine. Just this one for some reason gets the error. Corey On Fri, 16 Feb 2001, Bob Kline wrote: > On Fri, 16 Feb 2001, Corey Mosher wrote: > > > Hi, > > > > I am trying to test out the postgres-JDBC driver. I have a > > file called sample.java. It compiles fine, but when I run it > > I get the following error: > > > > Exception in thread "main" java.lang.NoClassDefFoundError: sample/java > > > > This is what my classpath is set to: > > > > export CLASSPATH=.:/usr/local/java_pkgs/jdk1.1.8/lib/postgresql.jar:$CLASSPATH > > > > Anyone have any idea as to what is wrong? It looks as if it can't > > find the sample.class file, but it does exist in the current > > directory. > > You might want to start with an introductory book on Java. It looks as > if you've included the source code filename extension in your > command-line invocation of the program. Drop the ".java" and see what > happens. > > Corey Mosher ----------------------------- Hub.Org Networking Services 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@hub.org Phone: (902) 542-3657 ----------------------------- PostgreSQL, Inc. 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@pgsql.com Phone: (902) 542-0713 ----------------------------- Fax: (902) 542-5386
On Fri, 16 Feb 2001, Corey Mosher wrote: > No, to run the program I am using: > java sample > > To compile it I am using: > javac sample.java > > I have had other simple programs running (the usual hello world > apps) and they seem to work fine. Just this one for some reason > gets the error. Let's take a look at the source, then, to see if we can spot the problem. -- Bob Kline mailto:bkline@rksystems.com http://www.rksystems.com
The source code is from the book: PostgreSQL: Introduction And Concepts Located at: http://www.postgresql.org/docs/aw_pgsql_book/node192.html I wanted to use some code that I knew worked to overcome problems like I am having. Corey On Fri, 16 Feb 2001, Bob Kline wrote: > On Fri, 16 Feb 2001, Corey Mosher wrote: > > > No, to run the program I am using: > > java sample > > > > To compile it I am using: > > javac sample.java > > > > I have had other simple programs running (the usual hello world > > apps) and they seem to work fine. Just this one for some reason > > gets the error. > > Let's take a look at the source, then, to see if we can spot the > problem. > > Corey Mosher ----------------------------- Hub.Org Networking Services 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@hub.org Phone: (902) 542-3657 ----------------------------- PostgreSQL, Inc. 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@pgsql.com Phone: (902) 542-0713 ----------------------------- Fax: (902) 542-5386
> Located at: http://www.postgresql.org/docs/aw_pgsql_book/node192.html > > I wanted to use some code that I knew worked to overcome problems > like I am having. There is nothing wrong with the code, to run it you'll need lines similar to: mstephen@sokoki:~$ export CLASSPATH=/home/mstephen/local/postgresql.jar:. mstephen@sokoki:~$ javac sample.java mstephen@sokoki:~$ java sample If these simple steps are not working for you then something very strange is going on. If the code is compiling then it is not a postgres or jdbc problem, but a problem with your VM, and I don't think this is the best place to find a solution. If it isn't compiling then get a new (as in, not broken, as opposed to recent, there is no code in sample which should not work in any version of the jdbc driver) postgres jar file and try again. Michael Stephenson mstephenson@openworld.co.uk Developer - Web Applications - Open World Tel: +44 1225 444 950 Fax: +44 1225 336 738
I'm not saying I doubt what you're telling me about how you're trying to run the program, but you might want to try again. Watch this: $ javac sample.java $ java sample Enter a state code: VA Virginia $ java sample.java Exception in thread "main" java.lang.NoClassDefFoundError: sample/java Look familiar? Good luck, Bob On Fri, 16 Feb 2001, Corey Mosher wrote: > The source code is from the book: > PostgreSQL: Introduction And Concepts > > Located at: http://www.postgresql.org/docs/aw_pgsql_book/node192.html > > I wanted to use some code that I knew worked to overcome problems > like I am having. > > Corey > > > On Fri, 16 Feb 2001, Bob Kline wrote: > > > On Fri, 16 Feb 2001, Corey Mosher wrote: > > > > > No, to run the program I am using: > > > java sample > > > > > > To compile it I am using: > > > javac sample.java > > > > > > I have had other simple programs running (the usual hello world > > > apps) and they seem to work fine. Just this one for some reason > > > gets the error. > > > > Let's take a look at the source, then, to see if we can spot the > > problem. > > > > > > Corey Mosher > > ----------------------------- > Hub.Org Networking Services > 251 Main St. > Wolfville, NS > Canada > B0P 1X0 > Email: corey@hub.org > Phone: (902) 542-3657 > ----------------------------- > PostgreSQL, Inc. > 251 Main St. > Wolfville, NS > Canada > B0P 1X0 > Email: corey@pgsql.com > Phone: (902) 542-0713 > ----------------------------- > Fax: (902) 542-5386 > -- Bob Kline mailto:bkline@rksystems.com http://www.rksystems.com
So there has got to be something wrong with the way I'm setting my classpath in that when I type java sample it is trying to use sample.java instead of sample.class. I'll play around with the classpath and see what I come up with. Thanks Bob, I appreciate it. Corey On Fri, 16 Feb 2001, Bob Kline wrote: > I'm not saying I doubt what you're telling me about how you're trying to > run the program, but you might want to try again. Watch this: > > $ javac sample.java > $ java sample > Enter a state code: VA > Virginia > $ java sample.java > Exception in thread "main" java.lang.NoClassDefFoundError: sample/java > > Look familiar? > > Good luck, > Bob > > On Fri, 16 Feb 2001, Corey Mosher wrote: > > > The source code is from the book: > > PostgreSQL: Introduction And Concepts > > > > Located at: http://www.postgresql.org/docs/aw_pgsql_book/node192.html > > > > I wanted to use some code that I knew worked to overcome problems > > like I am having. > > > > Corey > > > > > > On Fri, 16 Feb 2001, Bob Kline wrote: > > > > > On Fri, 16 Feb 2001, Corey Mosher wrote: > > > > > > > No, to run the program I am using: > > > > java sample > > > > > > > > To compile it I am using: > > > > javac sample.java > > > > > > > > I have had other simple programs running (the usual hello world > > > > apps) and they seem to work fine. Just this one for some reason > > > > gets the error. > > > > > > Let's take a look at the source, then, to see if we can spot the > > > problem. > > > > > > > > > > Corey Mosher > > > > ----------------------------- > > Hub.Org Networking Services > > 251 Main St. > > Wolfville, NS > > Canada > > B0P 1X0 > > Email: corey@hub.org > > Phone: (902) 542-3657 > > ----------------------------- > > PostgreSQL, Inc. > > 251 Main St. > > Wolfville, NS > > Canada > > B0P 1X0 > > Email: corey@pgsql.com > > Phone: (902) 542-0713 > > ----------------------------- > > Fax: (902) 542-5386 > > > > Corey Mosher ----------------------------- Hub.Org Networking Services 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@hub.org Phone: (902) 542-3657 ----------------------------- PostgreSQL, Inc. 251 Main St. Wolfville, NS Canada B0P 1X0 Email: corey@pgsql.com Phone: (902) 542-0713 ----------------------------- Fax: (902) 542-5386