you can try use Ion a useful library https://github.com/koush/ion and this is a example to upload multipart data
Ion.with(getContext(), "https://koush.clockworkmod.com/test/echo")
.uploadProgressBar(uploadProgressBar)
.setMultipartParameter("goop", "noop")
.setMultipartFile("filename.zip", new File("/sdcard/filename.zip"))
.asJsonObject()
.setCallback(...)