我一直在关注this将 Google 登录支持包含到我的桌面应用程序的教程。我正在使用的图书馆是 this one .

一切正常，这是 authorize() 方法的实现:

public Credential authorize() throws IOException {
    // Load client secrets.
    InputStream in = GoogleLogin.class.getResourceAsStream("/google/client_secret.json");
    GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

    // Build flow and trigger user authorization request.
    GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
            HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
            .setDataStoreFactory(DATA_STORE_FACTORY)
            .setAccessType("offline")
            .build();

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

    System.out.println("Credentials saved to " + DATA_STORE_DIR.getAbsolutePath());
    return credential;
}

但是，从 Credential 对象，我只能通过调用 Credential.getAccessToken() 来检索访问 token ，但我需要的是 id token 。用户通过身份验证后如何获取用户的 id_token？

最佳答案

在开始赏金之后，我真的明白了!可以通过继承 AuthorizedCodeInstalledApp 并提供您自己的 authorize()

这是我做的...

public class GoogleAuthCodeInstalledApp extends AuthorizationCodeInstalledApp {

    public GoogleAuthCodeInstalledApp(AuthorizationCodeFlow flow, VerificationCodeReceiver receiver) {
        super(flow, receiver);
    }

    @Override
    public Credential authorize(String userId) throws IOException {
        try {
            Credential credential = getFlow().loadCredential(userId);
            if (credential != null
                    && (credential.getRefreshToken() != null
                    || credential.getExpiresInSeconds() == null
                    || credential.getExpiresInSeconds() > 60)) {
                return credential;
            }
            // open in browser
            String redirectUri = getReceiver().getRedirectUri();
            AuthorizationCodeRequestUrl authorizationUrl
                    = getFlow().newAuthorizationUrl().setRedirectUri(redirectUri);
            onAuthorization(authorizationUrl);
            // receive authorization code and exchange it for an access token
            String code = getReceiver().waitForCode();
            GoogleTokenResponse response = (GoogleTokenResponse) getFlow().newTokenRequest(code).setRedirectUri(redirectUri).execute();
            System.out.println(response.getIdToken()); //YES, THIS IS THE ID TOKEN!!!
            // store credential and return it
            return getFlow().createAndStoreCredential(response, userId);
        } finally {
            getReceiver().stop();
        }
    }

}

在你这样做之后，而不是

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

使用:

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

更新 2018-05-29 - 我找到了更好、更可靠的解决方案

我发现这个解决方案通过在我们的 GoogleAuthorizationCodeFlow.Builder 中添加一个 CredentialCreatedListener 和一个 CredentialRefreshListener 来工作。

示例代码如下:

public Credential authorize() throws IOException {
    InputStream in = GoogleLogin.class.getResourceAsStream("/google/client_secret.json");
    GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));
    // Build flow and trigger user authorization request.
    flow = new GoogleAuthorizationCodeFlow.Builder(
            HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
            .setDataStoreFactory(DATA_STORE_FACTORY)
            .setAccessType("offline")
            .setCredentialCreatedListener(new AuthorizationCodeFlow.CredentialCreatedListener() {
                @Override
                public void onCredentialCreated(Credential credential, TokenResponse tokenResponse) throws IOException {
                    DATA_STORE_FACTORY.getDataStore("user").set("id_token", tokenResponse.get("id_token").toString());
                }
            })
            .addRefreshListener(new CredentialRefreshListener() {
                @Override
                public void onTokenResponse(Credential credential, TokenResponse tokenResponse) throws IOException {
                    DATA_STORE_FACTORY.getDataStore("user").set("id_token", tokenResponse.get("id_token").toString());
                }

                @Override
                public void onTokenErrorResponse(Credential credential, TokenErrorResponse tokenErrorResponse) throws IOException {
                    //handle token error response
                }
            })
            .build();

    Credential credential = new AuthorizationCodeInstalledApp(flow, serverReceiver).authorize("user");
    System.out.println("Credentials saved to " + DATA_STORE_DIR.getAbsolutePath());
    return credential;
}

代码几乎不言自明。每当通过调用 credential.refreshToken() 创建或刷新新的 Credential 时，监听器将收到通知，并且 id_token 将从TokenResponse(实际上是一个包含 id_token 字段的 GoogleTokenResponse 对象)，我们将使用默认的 DataStoreFactory 保存 id_token。 id_token 现在将保留在本地，并且每当调用 credential.refreshToken() 时都会由监听器自动更新。

关于java - 如何从凭据对象获取用户 ID token ？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49354891/