本指南說明如何設定簡單的 Android 應用程式,以便向 YouTube Data API 提出要求。
必要條件
如要執行這個快速入門導覽課程,您需要:
- Android Studio SDK 1.2 以上版本。
- API 23 以上的 Android SDK 套件,包括最新版 Google 存放區、Android 支援資料庫和 Google Play 服務。
- 可在測試裝置上存取網際網路。
- Google 帳戶。
本快速入門導覽課程假設您使用的是 Android Studio IDE (而非獨立的 SDK 工具),且能輕鬆在 Studio 專案中尋找、建立及編輯檔案。
步驟 1:取得 SHA1 指紋
在終端機中,執行下方的 Keytool 公用程式指令,取得您將用來啟用 API 的 SHA1 指紋。
keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore -list -v
系統要求您提供 KeyStore 密碼時,請輸入「android」。
Keytool 會將指紋列印至殼層。例如:
$ keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore -list -v Enter keystore password: Type "android" if using debug.keystore Alias name: androiddebugkey Creation date: Dec 4, 2014 Entry type: PrivateKeyEntry Certificate chain length: 1 Certificate[1]: Owner: CN=Android Debug, O=Android, C=US Issuer: CN=Android Debug, O=Android, C=US Serial number: 503bd581 Valid from: Mon Aug 27 13:16:01 PDT 2012 until: Wed Aug 20 13:16:01 PDT 2042 Certificate fingerprints: MD5: 1B:2B:2D:37:E1:CE:06:8B:A0:F0:73:05:3C:A3:63:DD SHA1: D8:AA:43:97:59:EE:C5:95:26:6A:07:EE:1C:37:8E:F4:F0:C8:05:C8 SHA256: F3:6F:98:51:9A:DF:C3:15:4E:48:4B:0F:91:E3:3C:6A:A0:97:DC:0A:3F:B2:D2:E1:FE:23:57:F5:EB:AC:13:30 Signature algorithm name: SHA1withRSA Version: 3
複製在上述範例中醒目顯示的 SHA1 指紋。
步驟 2:啟用 YouTube Data API
-
使用這個精靈在 Google Developers Console 中建立或選取專案,並自動啟用這個 API。依序點選「繼續」和「前往憑證」。
-
在「建立憑證」頁面上,按一下「取消」按鈕。
-
選取頁面頂端的「OAuth 同意畫面」分頁標籤。選取「Email address」(電子郵件地址),輸入「Product name」(產品名稱) (如果尚未設定),然後按一下「Save」(儲存) 按鈕。
-
選取「憑證」分頁標籤,按一下「建立憑證」按鈕,然後選取「OAuth 用戶端 ID」。
- 選取「Android」應用程式類型。
- 將步驟 1 中的 SHA1 指紋複製到「簽署憑證指紋」欄位。
- 在「Package name」(套件名稱) 欄位中輸入
com.example.quickstart
。 - 按一下「Create」(建立) 按鈕。
步驟 3:建立新的 Android 專案
- 開啟 Android Studio,然後開啟新的 Android Studio 專案。
- 在「New Project」畫面中,將應用程式命名為「quickstart」。
- 將「Company Domain」設為「example.com」,並確認自動產生的套件名稱與您在步驟 2 中在開發人員控制台輸入的名稱相符。按一下「Next」。
- 在「Target Android Devices」畫面中,勾選「Phone and Tablet」核取方塊,然後選擇「API 14: Android 4.0 (IceCreamSandwich)」的「Minimum SDK」。而不勾選其他核取方塊。按一下「Next」。
- 在「Add an activity to Mobile」畫面中,按一下「Add No Activity」。
- 按一下「Finish」。
此時,Android Studio 會建立並開啟專案。
步驟 4:準備專案
「專案」側欄會顯示 Android Studio 建立的預設專案檔案的可展開清單。在清單中展開 Gradle 指令碼清單,並開啟與「應用程式」模組 (而非專案) 相關聯的 build.gradle
檔案。
- 開啟應用程式
build.gradle
檔案,並將內容替換為以下內容: - 在工具列中,依序選取「Tools」>「Android」>「Sync Project with Gradle Files」。藉此取得並提供專案所需的程式庫。
- 找出並開啟預設的
src/main/AndroidManifest.xml
檔案。在「Project」側欄中,這個檔案以巢狀結構列於app
下方,然後在manifests
下方。將檔案內容替換成下列程式碼:<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.quickstart"> <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <uses-permission android:name="android.permission.GET_ACCOUNTS" /> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="YouTube Data API Android Quickstart" android:theme="@style/AppTheme" > <activity android:name=".MainActivity" android:label="YouTube Data API Android Quickstart" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
步驟 5:設定範例
建立新的 Java 類別。方法是先在「Project」側欄中選取 java
資料夾。這個資料夾會顯示在 app
個檔案群組中。按一下資料夾後,可以從選單列中依序選取.../app/src/main/java
。
將類別命名為「MainActivity」,然後按一下「OK」。使用下列程式碼取代新檔案的內容。
package com.example.quickstart; import com.google.android.gms.common.ConnectionResult; import com.google.android.gms.common.GoogleApiAvailability; import com.google.api.client.extensions.android.http.AndroidHttp; import com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential; import com.google.api.client.googleapis.extensions.android.gms.auth.GooglePlayServicesAvailabilityIOException; import com.google.api.client.googleapis.extensions.android.gms.auth.UserRecoverableAuthIOException; import com.google.api.client.http.HttpTransport; import com.google.api.client.json.JsonFactory; import com.google.api.client.json.jackson2.JacksonFactory; import com.google.api.client.util.ExponentialBackOff; import com.google.api.services.youtube.YouTubeScopes; import com.google.api.services.youtube.model.*; import android.Manifest; import android.accounts.AccountManager; import android.app.Activity; import android.app.Dialog; import android.app.ProgressDialog; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.AsyncTask; import android.os.Bundle; import android.support.annotation.NonNull; import android.text.TextUtils; import android.text.method.ScrollingMovementMethod; import android.view.View; import android.view.ViewGroup; import android.widget.Button; import android.widget.LinearLayout; import android.widget.TextView; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import pub.devrel.easypermissions.AfterPermissionGranted; import pub.devrel.easypermissions.EasyPermissions; public class MainActivity extends Activity implements EasyPermissions.PermissionCallbacks { GoogleAccountCredential mCredential; private TextView mOutputText; private Button mCallApiButton; ProgressDialog mProgress; static final int REQUEST_ACCOUNT_PICKER = 1000; static final int REQUEST_AUTHORIZATION = 1001; static final int REQUEST_GOOGLE_PLAY_SERVICES = 1002; static final int REQUEST_PERMISSION_GET_ACCOUNTS = 1003; private static final String BUTTON_TEXT = "Call YouTube Data API"; private static final String PREF_ACCOUNT_NAME = "accountName"; private static final String[] SCOPES = { YouTubeScopes.YOUTUBE_READONLY }; /** * Create the main activity. * @param savedInstanceState previously saved instance data. */ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout activityLayout = new LinearLayout(this); LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams( LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT); activityLayout.setLayoutParams(lp); activityLayout.setOrientation(LinearLayout.VERTICAL); activityLayout.setPadding(16, 16, 16, 16); ViewGroup.LayoutParams tlp = new ViewGroup.LayoutParams( ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT); mCallApiButton = new Button(this); mCallApiButton.setText(BUTTON_TEXT); mCallApiButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { mCallApiButton.setEnabled(false); mOutputText.setText(""); getResultsFromApi(); mCallApiButton.setEnabled(true); } }); activityLayout.addView(mCallApiButton); mOutputText = new TextView(this); mOutputText.setLayoutParams(tlp); mOutputText.setPadding(16, 16, 16, 16); mOutputText.setVerticalScrollBarEnabled(true); mOutputText.setMovementMethod(new ScrollingMovementMethod()); mOutputText.setText( "Click the \'" + BUTTON_TEXT +"\' button to test the API."); activityLayout.addView(mOutputText); mProgress = new ProgressDialog(this); mProgress.setMessage("Calling YouTube Data API ..."); setContentView(activityLayout); // Initialize credentials and service object. mCredential = GoogleAccountCredential.usingOAuth2( getApplicationContext(), Arrays.asList(SCOPES)) .setBackOff(new ExponentialBackOff()); } /** * Attempt to call the API, after verifying that all the preconditions are * satisfied. The preconditions are: Google Play Services installed, an * account was selected and the device currently has online access. If any * of the preconditions are not satisfied, the app will prompt the user as * appropriate. */ private void getResultsFromApi() { if (! isGooglePlayServicesAvailable()) { acquireGooglePlayServices(); } else if (mCredential.getSelectedAccountName() == null) { chooseAccount(); } else if (! isDeviceOnline()) { mOutputText.setText("No network connection available."); } else { new MakeRequestTask(mCredential).execute(); } } /** * Attempts to set the account used with the API credentials. If an account * name was previously saved it will use that one; otherwise an account * picker dialog will be shown to the user. Note that the setting the * account to use with the credentials object requires the app to have the * GET_ACCOUNTS permission, which is requested here if it is not already * present. The AfterPermissionGranted annotation indicates that this * function will be rerun automatically whenever the GET_ACCOUNTS permission * is granted. */ @AfterPermissionGranted(REQUEST_PERMISSION_GET_ACCOUNTS) private void chooseAccount() { if (EasyPermissions.hasPermissions( this, Manifest.permission.GET_ACCOUNTS)) { String accountName = getPreferences(Context.MODE_PRIVATE) .getString(PREF_ACCOUNT_NAME, null); if (accountName != null) { mCredential.setSelectedAccountName(accountName); getResultsFromApi(); } else { // Start a dialog from which the user can choose an account startActivityForResult( mCredential.newChooseAccountIntent(), REQUEST_ACCOUNT_PICKER); } } else { // Request the GET_ACCOUNTS permission via a user dialog EasyPermissions.requestPermissions( this, "This app needs to access your Google account (via Contacts).", REQUEST_PERMISSION_GET_ACCOUNTS, Manifest.permission.GET_ACCOUNTS); } } /** * Called when an activity launched here (specifically, AccountPicker * and authorization) exits, giving you the requestCode you started it with, * the resultCode it returned, and any additional data from it. * @param requestCode code indicating which activity result is incoming. * @param resultCode code indicating the result of the incoming * activity result. * @param data Intent (containing result data) returned by incoming * activity result. */ @Override protected void onActivityResult( int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); switch(requestCode) { case REQUEST_GOOGLE_PLAY_SERVICES: if (resultCode != RESULT_OK) { mOutputText.setText( "This app requires Google Play Services. Please install " + "Google Play Services on your device and relaunch this app."); } else { getResultsFromApi(); } break; case REQUEST_ACCOUNT_PICKER: if (resultCode == RESULT_OK && data != null && data.getExtras() != null) { String accountName = data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME); if (accountName != null) { SharedPreferences settings = getPreferences(Context.MODE_PRIVATE); SharedPreferences.Editor editor = settings.edit(); editor.putString(PREF_ACCOUNT_NAME, accountName); editor.apply(); mCredential.setSelectedAccountName(accountName); getResultsFromApi(); } } break; case REQUEST_AUTHORIZATION: if (resultCode == RESULT_OK) { getResultsFromApi(); } break; } } /** * Respond to requests for permissions at runtime for API 23 and above. * @param requestCode The request code passed in * requestPermissions(android.app.Activity, String, int, String[]) * @param permissions The requested permissions. Never null. * @param grantResults The grant results for the corresponding permissions * which is either PERMISSION_GRANTED or PERMISSION_DENIED. Never null. */ @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); EasyPermissions.onRequestPermissionsResult( requestCode, permissions, grantResults, this); } /** * Callback for when a permission is granted using the EasyPermissions * library. * @param requestCode The request code associated with the requested * permission * @param list The requested permission list. Never null. */ @Override public void onPermissionsGranted(int requestCode, List<String> list) { // Do nothing. } /** * Callback for when a permission is denied using the EasyPermissions * library. * @param requestCode The request code associated with the requested * permission * @param list The requested permission list. Never null. */ @Override public void onPermissionsDenied(int requestCode, List<String> list) { // Do nothing. } /** * Checks whether the device currently has a network connection. * @return true if the device has a network connection, false otherwise. */ private boolean isDeviceOnline() { ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connMgr.getActiveNetworkInfo(); return (networkInfo != null && networkInfo.isConnected()); } /** * Check that Google Play services APK is installed and up to date. * @return true if Google Play Services is available and up to * date on this device; false otherwise. */ private boolean isGooglePlayServicesAvailable() { GoogleApiAvailability apiAvailability = GoogleApiAvailability.getInstance(); final int connectionStatusCode = apiAvailability.isGooglePlayServicesAvailable(this); return connectionStatusCode == ConnectionResult.SUCCESS; } /** * Attempt to resolve a missing, out-of-date, invalid or disabled Google * Play Services installation via a user dialog, if possible. */ private void acquireGooglePlayServices() { GoogleApiAvailability apiAvailability = GoogleApiAvailability.getInstance(); final int connectionStatusCode = apiAvailability.isGooglePlayServicesAvailable(this); if (apiAvailability.isUserResolvableError(connectionStatusCode)) { showGooglePlayServicesAvailabilityErrorDialog(connectionStatusCode); } } /** * Display an error dialog showing that Google Play Services is missing * or out of date. * @param connectionStatusCode code describing the presence (or lack of) * Google Play Services on this device. */ void showGooglePlayServicesAvailabilityErrorDialog( final int connectionStatusCode) { GoogleApiAvailability apiAvailability = GoogleApiAvailability.getInstance(); Dialog dialog = apiAvailability.getErrorDialog( MainActivity.this, connectionStatusCode, REQUEST_GOOGLE_PLAY_SERVICES); dialog.show(); } /** * An asynchronous task that handles the YouTube Data API call. * Placing the API calls in their own task ensures the UI stays responsive. */ private class MakeRequestTask extends AsyncTask<Void, Void, List<String>> { private com.google.api.services.youtube.YouTube mService = null; private Exception mLastError = null; MakeRequestTask(GoogleAccountCredential credential) { HttpTransport transport = AndroidHttp.newCompatibleTransport(); JsonFactory jsonFactory = JacksonFactory.getDefaultInstance(); mService = new com.google.api.services.youtube.YouTube.Builder( transport, jsonFactory, credential) .setApplicationName("YouTube Data API Android Quickstart") .build(); } /** * Background task to call YouTube Data API. * @param params no parameters needed for this task. */ @Override protected List<String> doInBackground(Void... params) { try { return getDataFromApi(); } catch (Exception e) { mLastError = e; cancel(true); return null; } } /** * Fetch information about the "GoogleDevelopers" YouTube channel. * @return List of Strings containing information about the channel. * @throws IOException */ private List<String> getDataFromApi() throws IOException { // Get a list of up to 10 files. List<String> channelInfo = new ArrayList<String>(); ChannelListResponse result = mService.channels().list("snippet,contentDetails,statistics") .setForUsername("GoogleDevelopers") .execute(); List<Channel> channels = result.getItems(); if (channels != null) { Channel channel = channels.get(0); channelInfo.add("This channel's ID is " + channel.getId() + ". " + "Its title is '" + channel.getSnippet().getTitle() + ", " + "and it has " + channel.getStatistics().getViewCount() + " views."); } return channelInfo; } @Override protected void onPreExecute() { mOutputText.setText(""); mProgress.show(); } @Override protected void onPostExecute(List<String> output) { mProgress.hide(); if (output == null || output.size() == 0) { mOutputText.setText("No results returned."); } else { output.add(0, "Data retrieved using the YouTube Data API:"); mOutputText.setText(TextUtils.join("\n", output)); } } @Override protected void onCancelled() { mProgress.hide(); if (mLastError != null) { if (mLastError instanceof GooglePlayServicesAvailabilityIOException) { showGooglePlayServicesAvailabilityErrorDialog( ((GooglePlayServicesAvailabilityIOException) mLastError) .getConnectionStatusCode()); } else if (mLastError instanceof UserRecoverableAuthIOException) { startActivityForResult( ((UserRecoverableAuthIOException) mLastError).getIntent(), MainActivity.REQUEST_AUTHORIZATION); } else { mOutputText.setText("The following error occurred:\n" + mLastError.getMessage()); } } else { mOutputText.setText("Request cancelled."); } } } }
步驟 6:執行應用程式
- 如要測試應用程式,請依序點選「Run」>「Run app」選單項目。
- 系統會提示您選取用來執行應用程式的已連線裝置 (建議) 或模擬。如果您要執行模擬,請確定設定為使用其中一個「使用 Google API 的」系統映像檔。如果您嘗試在尚未安裝 Google Play 服務的裝置上執行快速入門導覽課程,快速入門導覽課程會產生對話方塊讓您安裝。
- 如果是在模擬器上執行,請允許模擬器完全啟動並建立網路連線。
- 如果是首次啟動模擬器,您可能需要解鎖螢幕。無論如何,快速入門導覽課程應用程式應會自動啟動。
- 首次執行應用程式時,系統會提示您指定帳戶。完成登入流程,選擇要連結的帳戶。
- 選取帳戶後,應用程式會提示您授予存取權。按一下「OK」進行授權。
附註
- 授權資訊會儲存在應用程式,因此後續的執行作業不會提示使用者進行授權。
延伸閱讀
- Google Developers Console 說明文件
- 適用於 Java 的 Google API 用戶端說明文件
- Android API 指南
- Google Play 服務
- YouTube Data API 參考說明文件
疑難排解
未註冊的 Android 應用程式
如果 OAuth 對話方塊中包含「未註冊的 Android 應用程式」項目,表示找不到您在步驟 2 建立的 OAuth2 用戶端 ID,而 Android 將改回預設用戶端。預設用戶端不會設為使用此 API,因此如 accessNotConfigured.
等錯誤導致要求失敗,這些錯誤也可能提及預設專案編號 608941808256
。
如要修正這個問題,請確認您在步驟 1 中擷取的 SHA1 指紋與 build.gradle
檔案中列出的 applicationId
,與您在 Google Developers Console 中設定的值完全一致。