Importing zip file as library - Eclipse Java

Question

I stucked here importing google http library. I made some research in links such as:

1. Eclipse, Java: How to import a library in zip-format?
2. Import Libraries in Eclipse?

The thing is, I imported correctly and was working right. But after some point it stopped to work. I creater one user library, imported the zip file which contain the library but it's not sort of "compiling the library".

Take a look at the print, please:

I'm trying to solve on my own for four hours but I'm getting tired... could anyone help me please?

Edit One:

Edit Two:

Solution

Did some more research and found this:

1. How to add external library properly in Eclipse?

I then followed the steps:

1. Extracted all google api content to one folder named lib
2. Created a New User Librarby Window -> Preference -> Java -> Build Path -> New -> Name your library -> left the System Library unchecked -> Add External Jars -> manually added the needed jars.
3. Right click on project folder -> Build Path -> Configure Build Path -> Libraries -> Add Library -> User Library -> checked the created user library.

In conclusion: Don't ever import the library as a zip or you will have a long headache.

Hope this helps someone else.

Edit: In case of some error showing up, like missing files belonging to the user library, cleaning the project may prove to be a solution. However, refreshing the project worked just fine for me. Try pressing F5 or right clicking on your project folder and select refresh.