本指南介绍了如何设置一个简单的 Android 应用，该应用会向 YouTube Data API 发出请求。
前提条件
如需运行本快速入门，您需要满足以下条件：
- 适用于 API 23 或更高版本的 Android SDK 软件包，包括最新版本的 Google 代码库、Android 支持库和 Google Play 服务。
- 测试设备可以访问互联网。
- Google 账号。
此快速入门指南将假定您使用的是 Android Studio IDE（而非独立的 SDK 工具），并且能够轻松地在 Studio 项目中查找、创建和修改文件。
第 1 步：获取 SHA1 指纹
在终端中，运行以下 Keytool 实用程序命令，获取将用于启用 API 的 SHA1 指纹。
keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore -list -v
当系统要求输入密钥库密码时，请输入“android”。
Keytool 将指纹输出到 shell 程序中。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
复制以上示例中亮色显示的 SHA1 指纹。
第 2 步：启用 YouTube Data API
com.example.quickstart第 3 步：创建新的 Android 项目
- 打开 Android Studio，然后启动新的 Android Studio 项目。
- 在新项目界面中，将应用命名为“Quickstart”。
- 将公司网域设置为“example.com”，并验证自动生成的软件包名称是否与您在第 2 步中输入到开发者控制台中的软件包名称一致。 点击 Next。
- 在 Target Android Devices 界面中，选中 Phone and Tablet 复选框，然后选择 Minimum SDK 为“API 14: Android 4.0 (IceCreamSandwich)”。取消选中其他复选框。点击下一步。
- 在 Add an activity to Mobile 界面中，点击 Add No Activity。
- 点击完成。
此时，Android Studio 会创建并打开项目。
第 4 步：准备项目
build.gradle<?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>
第 5 步：设置示例
javaapp.../app/src/main/java将该类命名为“MainActivity”，然后点击确定。将新文件的内容替换为以下代码。
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.");
}
}
}
}
第 6 步：运行应用
- 如需测试应用，请点击 Run > Run app 菜单项。
- 系统会提示您选择要运行应用的已连接设备（推荐）或模拟器。如果您在模拟器上运行，请确保该模拟器已配置为使用包含 Google API 的系统映像。如果您尝试在当前未安装 Google Play 服务的设备上运行快速入门，快速入门会生成一个对话框，您可以通过该对话框安装 Google Play 服务。
- 如果是在模拟器上运行，请允许模拟器完全启动并建立网络连接。
- 如果首次启动模拟器，您可能需要解锁其屏幕。无论如何，快速入门应用都应会自动启动。
- 首次运行该应用时，系统会提示您指定账号。完成登录流程，选择要关联的账号。
- 选择账号后，应用会提示您授权访问。 点击确定进行授权。
备注
- 授权信息会与应用一起存储，因此后续执行不会提示进行授权。
深入阅读
问题排查
此 Android 应用尚未注册
accessNotConfigured.608941808256build.gradleapplicationId