Google Sheets API异常

Question

我正在尝试使用Google表格API写入Google表格文档。我正在使用快速入门中提供的示例代码，但是却遇到了空指针异常。错误发生在此行

Sheets.Spreadsheets.Values.Update request = sheetsService.spreadsheets().values() .update(spreadsheetID, range, valRange);

我相信这是因为这行返回一个空对象

Sheets sheetsService = createSheetsService();

下面是createSheetsService（）方法的代码。

public static Sheets createSheetsService() throws IOException {
    try {
        HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();

        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();

        // TODO: Change placeholder below to generate authentication credentials. See
        // https://developers.google.com/sheets/quickstart/java#step_3_set_up_the_sample
        //
        // Authorize using one of the following scopes:
        //   "https://www.googleapis.com/auth/drive"
        //   "https://www.googleapis.com/auth/drive.file"
        //   "https://www.googleapis.com/auth/spreadsheets"
        //   "https://www.googleapis.com/auth/cloud-platform"
        GoogleCredential credential = GoogleCredential.fromStream(new FileInputStream("PathToProject"))
                .createScoped(Lists.newArrayList("https://www.googleapis.com/auth/cloud-platform"));

        return new Sheets.Builder(httpTransport, jsonFactory, credential)
                .setApplicationName("Test App")
                .build();
    } catch (GeneralSecurityException e) {
        Log.e(TAG, "Security Exception " + e.getMessage());
        return null;
    }
}

我很确定这是由于末尾的catch语句而返回null。但是，如果我尝试抛出GeneralSecurityException而不是使用try catch，则会出现此错误

Unhandled exception: java.security.GeneralSecurityException

我真的很茫然，非常感谢您的帮助。 这是我的MainActivity.java文件中的其余代码

public class MainActivity extends AppCompatActivity {

private static final String TAG = "MainActivity";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    EditText nameText = (EditText) findViewById(R.id.editText);
    Button submit = (Button) findViewById(R.id.button);
    final String name = nameText.getText().toString();

    submit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            write(name);

        }
    });
}


public static void write(String args) {
    try {
        String spreadsheetID = "mySpreadSheetID";
        String valueInputOption = "RAW";
        BatchUpdateValuesRequest requestBody = new BatchUpdateValuesRequest();
        List<ValueRange> data = new ArrayList<>();
        //List<List<Object>> vals = Arrays.asList(Arrays.asList((Object) "hello world"));
        ValueRange valRange = new ValueRange();
        valRange.setValues(
                Arrays.asList(
                        Arrays.asList((Object) ""),
                        Arrays.asList((Object) "Row 2 Cell 1", (Object) "Row 2 Cell 2")));


        String range = "A2";
        valRange.setRange(range);

        Sheets sheetsService = createSheetsService();
        Sheets.Spreadsheets.Values.Update request = sheetsService.spreadsheets().values()
                .update(spreadsheetID, range, valRange);
        request.setValueInputOption(valueInputOption);
        UpdateValuesResponse response = request.execute();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public static Sheets createSheetsService() throws IOException {
   try {
        HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();

        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();

        // TODO: Change placeholder below to generate authentication credentials. See
        // https://developers.google.com/sheets/quickstart/java#step_3_set_up_the_sample
        //
        // Authorize using one of the following scopes:
        //   "https://www.googleapis.com/auth/drive"
        //   "https://www.googleapis.com/auth/drive.file"
        //   "https://www.googleapis.com/auth/spreadsheets"
        //   "https://www.googleapis.com/auth/cloud-platform"
        GoogleCredential credential = GoogleCredential.fromStream(new FileInputStream("PathToProject"))
                .createScoped(Lists.newArrayList("https://www.googleapis.com/auth/cloud-platform"));

        return new Sheets.Builder(httpTransport, jsonFactory, credential)
                .setApplicationName("TestApp")
                .build();
   } catch (GeneralSecurityException e) {
        Log.e(TAG, "Security Exception " + e.getMessage());
        return null;
   }
}

}