request formData to API, gets “Network Error” in axios while uploading image

Project keeps flipper java file under app > source > debug in react native > 0.62. There is an issue with Flipper Network that causes the problem in your case. If you remove the debug folder, you will not be able to debug Android with Flipper, so the best solution is upgrading Flipper version in android > gradle.properties to 0.46.0 that fixes the problem.

You can change it with this line FLIPPER_VERSION=0.46.0

react-nativeandroid

The issue that I was facing which is close to what you are mentioning is that I was getting NetworkError when using image-picker and trying to upload the file using axios. It was working perfectly in iOS but not working in android.

This is how I solved the issue.

There are two independent issues at action here. Let’s say we get imageUri from image-picker, then we would use these following lines of code to upload from the frontend.

const formData = new FormData();
formData.append('image', {
 uri : imageUri,
 type: "image",
 name: imageUri.split("/").pop()
});

The first issue is with the imageUri itself. If let’s say photo path is /user/.../path/to/file.jpg. Then file picker in android would give imageUri value as file:/user/.../path/to/file.jpg whereas file picker in iOS would give imageUri value as file:///user/.../path/to/file.jpg.

The solution for the first issue is to use file:// instead of file: in the formData in android.

The second issue is that we are not using proper mime-type. It is working fine on iOS but not on Android. What makes this worse is that the file-picker package gives the type of the file as “image” and it does not give proper mime-type.

The solution is to use proper mime-type in the formData in the field type. Ex: mime-type for .jpg file would be image/jpeg and for .png file would be image/png. We do not have to do this manually. Instead, you can use a very famous npm package called mime.

The final working solution is:

import mime from "mime";

const newImageUri =  "file:///" + imageUri.split("file:/").join("");

const formData = new FormData();
formData.append('image', {
 uri : newImageUri,
 type: mime.getType(newImageUri),
 name: newImageUri.split("/").pop()
});

I hope this helps to solve your problem :)