They are automatically added to the project classpath if its a web project. Sometimes it does not work properly, a refresh or close/open of the project helps.
if its not a web project you can right click on the library and go to "Build Path" -> "Add to Build Path"
In case this helps anyone, if you are using a Git repo, make sure the jars make it into the WEB-INF/lib INSIDE the git repo and not just in the project WEB-INF/lib
Check under project properties -> deployment assembly if jar file are under deployed path- WEB-INF/lib if not use add button and add jar under WEB-INF/lib
sometime eclipse (in my case Juno Service Release 2 ) was not doing it for me so i did manually. this worked for me.
Found a solution. This problem happens, when you import a project.
The solution is simple
Now you should see the web app libraries showing your jars added.
Pasting the jar files in WebContent\WEB-INF\lib via the file system was the only way it worked for me.
They then appeared under the Deployed Resources and WebContent lib sub-folders.
When I looked, the build path had the jars in the Web App Libraries and everything built and ran fine.
Add the jar file to your WEB-INF/lib folder. Right-click your project in Eclipse, and go to "Build Path > Configure Build Path" Add the "Web App Libraries" library This will ensure all WEB-INF/lib jars are included on the classpath. helped me..
Drag and drop in WEB-INF/lib folder and restart eclipse ans start webservice then create client
add the jar to WEB-INF/lib from file structure refresh the project, you should see the jar now visible under the WEB-INF/lib folder.
this is the best solution that worked for me
From the ToolBar to go
Project> Properties>Java Build Path > Add External Jars.
Locate the File on the local disk or web Directory and Click Open.
This will automatically add the required Jar files to the Library.
Source: Stackoverflow.com