使用Selenium和java的文件上传功能

I need to automate the file upload feature in a web console and i am using selenium and java for this. I tried multiple approaches but when i click on upload button and windows explorer gets opened, it stops there. doesn't select any file...and gives error that there is no file.. I tried in firefox and chrome both but i am not able to solve this problem.I need to automate the file upload feature in a