class.getResourceAsStream 在 android studio 中返回 null

Question

I'm trying to create an app in android studio that can access a google sheet. My credentials.json file is like this

{"client_id":[My ID], "project_id":"androidandsheets", "auth_uri":[My auth URI], "token_uri":[My token URI], "auth_provider_x509_cert_url":[URL]}

but when I use this java code

private Credential authorize() throws IOException, GeneralSecurityException{
    InputStream in = SheetsAndJava.class.getResourceAsStream("credentials.json");
    GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(
            GsonFactory.getDefaultInstance(),new InputStreamReader(in)
    );
    List<String> scopes = Arrays.asList(SheetsScopes.SPREADSHEETS);

    GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
            GoogleNetHttpTransport.newTrustedTransport(),
            GsonFactory.getDefaultInstance(),
            clientSecrets,scopes
            ).setDataStoreFactory(new FileDataStoreFactory(new File("tokens")))
            .setAccessType("offline").build();

    Credential credential = new AuthorizationCodeInstalledApp(
            flow,new LocalServerReceiver()
    ).authorize("user");

    return credential;
}

the input stream returned by InputStream in = SheetsAndJava.class.getResourceAsStream("credentials.json") is null. Can someone please me fix this issue. Here's my layout for this project. For some reason the credentials.json file is visible in project view but not in android view.

Android View

Project View

Answer 1

Class#getResource and Class#getResourceAsStream looks for the resource relative to the class/in the same package. This leaves you with multiple options:

move credentials.json

Since it is looking for the credentials.json file in com/example/excelintro , the problem should be solved by just moving it to res/com/example/excelintro .

Use ClassLoader#getResource / ClassLoader#getResourceAsStream

Instead of callng SheetsAndJava.class.getResourceAsStream(...) (or SheetsAndJava.class.getResource(...) ) (which resolves the resource relative to the class), you can use SheetsAndJava.class.getClassLoader().getResourceAsStream(...) (or SheetsAndJava.class.getClassLoader().getResource(...) ). This resolves the resource relative to the classpath root (the res folder).

Append a leading / to the resource name

If you use /credentials.json instead of just credentials.json , it should also resolve the resource from the classpath root.