Error: No class definition found

I have added jars with the below procedure:

1. Right-click on the project in Eclipse and select “Build Path -> Add Libraries…”.
2. Select User Library from the list and click Next.
3. Click the “User Libraries…” button.
4. Click “New…” in the User Libraries dialog.
5. Give the user library a name and select the System library checkbox and click OK.
6. Highlight the newly added user library in the list and click the “Add JARs…” button and add the desired jar files.
7. Click OK on the User Libraries dialog.
8. Make sure the new user library is chec开发者_高级运维ked in the Add Library dialog.

After running the application it is saying that "No class definition found" and "could not find the class" errors.

if u want add jar file follow this procedure.

right click on project-->properties-->java build path-->add external jar's-->select your
required jar want to add from where u store add alick on ok.