问必须定义指向定义凭据的文件的java.io.IOException:Environment变量GOOGLE_APPLICATION_CREDENTIALS

EN

 private void recognizeSpeech(){
    try{
        SpeechClient speechClient = SpeechClient.create();
        String languageCode="en-US";
        int sampleRateHertz=16000;
        RecognitionConfig.AudioEncoding encoding = RecognitionConfig.AudioEncoding.LINEAR16;
        RecognitionConfig config =
                RecognitionConfig.newBuilder()
                        .setLanguageCode(languageCode)
                        .setSampleRateHertz(sampleRateHertz)
                        .setEncoding(encoding)
                        .build();
        Path path = Paths.get(fileName);
        byte[] data = Files.readAllBytes(path);
        ByteString content = ByteString.copyFrom(data);
        RecognitionAudio audio = RecognitionAudio.newBuilder().setContent(content).build();
        RecognizeRequest request =
                RecognizeRequest.newBuilder().setConfig(config).setAudio(audio).build();
        RecognizeResponse response = speechClient.recognize(request);
        for (SpeechRecognitionResult result : response.getResultsList()) {
            // First alternative is the most probable result
            SpeechRecognitionAlternative alternative = result.getAlternativesList().get(0);
            outputText.setText(alternative.getTranscript());
        }
    }
    catch (Exception e){
        Toast.makeText(this, e.toString(), Toast.LENGTH_SHORT).show();
    }
}