Fix the function in java for android

I am looking for a freelancer who are expert in java for android. I am working on uploadfile function in java that when I select the file, I will get the instantly response from the server using with httpurlconnection method, but when I select more than one file, it take a while to get a response from the server which it take like 30 seconds or 50 seconds. It should get a instantly response from the server when I select more than one file at the same time before I upload the file. I want you to check on the code to see if you can fix it.I will only pay when the work is done. No time wasters please. 1 day deadline and the project is $40. Thank you!!!