Question: how to use zxing barcode scanner in android?
Answer: Unzip zxing-master.zip, Use eclipse to import "android" project in zxing-master.
Create "libs" folder in "android" project and paste cor-3.2.1.jar into the libs folder.
Click on project: choose "properties" -> "Java Compiler" to change level to 1.7. ... 
If "CameraConfigurationUtils. ... 
Clean and build project.