Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference

I am running the Android application with react-native run-android. The application crashing at the entry with the following error

Attempt to invoke virtual method ‘boolean java.lang.String.equals(java.lang.Object)’ on a null object reference

Environment

Environment: OS: Windows 10 Node: 6.10.2 Yarn: 1.5.1 npm: 3.10.10 Watchman: Not Found Xcode: N/A Android Studio: Not Found

The machine does have Android Studio and Android SDK.

Packages: (wanted => installed) react: ^16.3.0-alpha.1 => 16.3.0-alpha.2 react-native: 0.54.2 => 0.54.2

Expected Behavior

The application should open normally

Actual Behavior

The application is crashing with the following errors.

Steps to Reproduce

As this is a private project cannot give the code and steps to reproduce.

[danihodovic]

I’ve ran into the same issue. The error message originates from

https://github.com/facebook/react-native/blob/e636eb60d7c8cff3a73183e02d9d457d32a6ec53/ReactAndroid/src/main/java/com/facebook/react/modules/blob/BlobModule.java#L81-L82

On line 81 the developer tries to extract the scheme (http/https) the request is using, but the method uri.getScheme() is returning null. That means your request has no scheme. Line 82 attempts to call a virtual method which doesn’t exist for the value null.

Add a scheme to your request and the problem should go away.

We should submit a PR to provide a clearer error message when the request doesn’t have a scheme.

[bchr28]

componentDidMount() {
    this.getBanner();
  }
  
  getBanner = () => {
    fetch(API_URL_BANNER, {
      method: 'POST',
      headers: {
        Accept: 'application/json',
        'Content-Type': 'application/json'
      },
      body : JSON.stringify(
        {server_key: SERVER_KEY, client_key: CLIENT_KEY}),
      })
        .then((response) => response.json()).then((responseJson) => {
          responseJson = responseJson['data'];
          console.log(responseJson);
        }).catch((error) => {
      console.error(error);
    });
  }

I got same issue here, error show where I get data from API, and in log show

ReactNative: CatalystInstanceImpl.destroy() start ReactNative: CatalystInstanceImpl.destroy() end

FYI I use “react”: “16.3.0-alpha.1”, “react-native”: “0.54.2”,