Some times you may face this error, but may not get the right answer so i though it is better to post with steps to over come this error.
This problem occurs at run-time not at compile time, first search commons-codec.jar
if commons-codec.jar file is not on above mention location then download if from commons-codec.jar file and. now we have our jar file ready so follow the steps to add it to build path.
- click on Windows menu
- then click on Preferences
- search “ClassPath variables” at top left search text box.
- result will be come then click on ClassPath variables. new popup window will be appeared.
- Click on new button give name for your ClassPath variable, and then browse for commons-codec.jar and add it.
- here on done click on OK button and closed all the windows.
see the below screen for more details.