Youtube API中的NullPointerExceptions

问题描述

我目前正在尝试学习如何使用Youtube API和其他内容，但是却遇到了一些NullPointerException错误，我只是想不通为什么...

我已经尝试了可以​​在文档中找到的所有内容，但是没有任何改变。

private static final String APPLICATION_NAME = "API code samples";
private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();

/**
 * Create an authorized Credential object.
 *
 * @return an authorized Credential object.
 * @throws IOException
 */
public static Credential authorize(final NetHttpTransport httpTransport) throws IOException {
    // Load client secrets.
    InputStream in = Createbroadcast.class.getResourceAsstream(CLIENT_SECRETS);
    GoogleClientSecrets clientSecrets =
      GoogleClientSecrets.load(JSON_FACTORY,new InputStreamReader(in));
    // Build flow and trigger user authorization request.
    GoogleAuthorizationCodeFlow flow =
        new GoogleAuthorizationCodeFlow.Builder(httpTransport,JSON_FACTORY,clientSecrets,ScopES)
        .build();
    Credential credential =
        new AuthorizationCodeInstalledApp(flow,new LocalServerReceiver()).authorize("user");
    return credential;
}

/**
 * Build and return an authorized API client service.
 *
 * @return an authorized API client service
 * @throws GeneralSecurityException,IOException
 */
public static YouTube getService() throws GeneralSecurityException,IOException {
    final NetHttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
    Credential credential = authorize(httpTransport);
    return new YouTube.Builder(httpTransport,credential)
        .setApplicationName(APPLICATION_NAME)
        .build();
}

/**
 * Call function to create API service object. Define and
 * execute API request. Print API response.
 *
 * @throws GeneralSecurityException,IOException,GoogleJsonResponseException
 */
public static void main(String[] args)
    throws GeneralSecurityException,GoogleJsonResponseException {
    YouTube youtubeService = getService();
    
    // Define the Livebroadcast object,which will be uploaded as the request body.
    Livebroadcast livebroadcast = new Livebroadcast();
    
    // Add the contentDetails object property to the Livebroadcast object.
    LivebroadcastContentDetails contentDetails = new LivebroadcastContentDetails();
    contentDetails.setEnableClosedCaptions(true);
    contentDetails.setEnableContentEncryption(true);
    contentDetails.setEnableDvr(true);
    contentDetails.setEnableEmbed(true);
    contentDetails.setRecordFromStart(true);
    contentDetails.setStartWithSlate(true);
    livebroadcast.setContentDetails(contentDetails);
    
    // Add the snippet object property to the Livebroadcast object.
    LivebroadcastSnippet snippet = new LivebroadcastSnippet();
    snippet.setScheduledStartTime(new DateTime("2024-01-30T00:00:00.000Z"));
    snippet.setTitle("Test broadcast");
    livebroadcast.setSnippet(snippet);
    
    // Add the status object property to the Livebroadcast object.
    LivebroadcastStatus status = new LivebroadcastStatus();
    status.setPrivacyStatus("unlisted");
    livebroadcast.setStatus(status);

    // Define and execute the API request
    YouTube.Livebroadcasts.Insert request = youtubeService.livebroadcasts()
        .insert("snippet,contentDetails,status",livebroadcast);
    Livebroadcast response = request.execute();
    System.out.println(response);
}

这些是我不断得到的错误：

Exception in thread "main" java.lang.NullPointerException
at java.base/java.io.Reader.<init>(Reader.java:167)
at java.base/java.io.InputStreamReader.<init>(InputStreamReader.java:72)
at com.google.api.services.samples.youtube.cmdline.live.Createbroadcast.authorize(Createbroadcast.java:47)
at com.google.api.services.samples.youtube.cmdline.live.Createbroadcast.getService(Createbroadcast.java:65)
at com.google.api.services.samples.youtube.cmdline.live.Createbroadcast.main(Createbroadcast.java:79)

如果这是一个愚蠢的问题，我非常抱歉：) 在此先感谢，Thilo

解决方法

很可能找不到Animal.new('kit','Hank',7) #=> #<Animal:0x000056fa311fd9c0 @ident="kit",@family="Hank",# @age=7,@lifespan=14,@breed_mix="Tabby"> Animal.new('kat','Boots',4) #=> #<Animal:0x000056fa31212cf8 @ident="kat",@family="Boots",# @age=4,@lifespan=18,@breed_mix="Siamese"> 资源，并且CLIENT_SECRETS返回CreateBroadcast.class.getResourceAsStream(CLIENT_SECRETS)。在下一行中用null调用new InputStreamReader(in)会得到NPE。

,

这与YouTube API无关。

CreateBroadcast.class.getResourceAsStream(CLIENT_SECRETS)返回空值as the documentation states it will，因为CLIENT_SECRETS不包含指向现有资源的资源URL。

请注意，它必须是相对URL，而不是文件路径。相对网址表示在所有平台上均带有斜杠（/）的路径。

如果您从.jar文件运行，则只需验证.jar文件是否包含您所请求的资源即可：

• 如果CLIENT_SECRETS以初始斜杠开头，则它相对于.jar文件的根目录。这意味着，如果CLIENT_SECRETS为"/config/secrets.txt"，则您的.jar文件需要包含一个config/secrets.txt条目。
• 如果CLIENT_SECRETS并非以斜杠开头，则相对于CreateBroadcast类的包。这意味着，如果CLIENT_SECRETS为"secrets.txt"，则.jar文件需要包含一个com/google/api/services/samples/youtube/cmdline/live/secrets.txt条目。

如果不是从.jar文件运行，则应用相同的规则，但是您需要检查运行时类路径中由IDE添加的每个目录。许多IDE将遵循Maven约定，并且仅使用项目中的target / classes子目录。

在所有情况下，如果CLIENT_SECRETS的值不是现有资源的路径，则getResourceAsStream方法将返回null。然后，您将该空值传递给new InputStreamReader，这是导致异常的原因。