关于动态更新

  • Google 考虑自家 Android 应用安全和苹果策略， 本来在 2019 的 roadmap 里面有这样一项，roadmap公布后，过一段时间后面又移除了这一项，目前不是主航道。
  • Android 目前可以通过整包方式实现动态更新， iOS 目前还不支持。

Android Flutter 整包动态更新实现

Flutter 构建产物加载流程

  • 在 Flutter Android 启动流程 一文中，我们知道了 Android Flutter 启动流程，启动时，会去加载 data/data/{AppPackage}/app_flutter 下面如下文件。 
  1. isolate_snapshot_instr              - 应用程序指令段
  2. isolate_snapshot_data               - 应用程序数据段
  3. vm_snapshot_instr                   - DartVM 指令段
  4. vm_snapshot_data                    - DartVM 数据段

apk-update.png

Flutter 构建产物

  • 在 Flutter Android 混合工程实践 一文中，详细阐述了生成 Flutter 构建产物的流程。我们可以把构建产物打成压缩包上传到 CDN，然后 Native 通过下载服务器 Flutter 整体更新包进行更新。

**

  1. import android.Manifest;
  2. import android.app.DownloadManager;
  3. import android.content.BroadcastReceiver;
  4. import android.content.Context;
  5. import android.content.Intent;
  6. import android.content.IntentFilter;
  7. import android.content.pm.PackageManager;
  8. import android.net.Uri;
  9. import android.os.Bundle;
  10. import android.os.Environment;
  11. import android.support.v4.app.ActivityCompat;
  12. import android.support.v4.content.ContextCompat;
  13. import android.util.Log;
  14. import android.view.View;
  15. import android.widget.Button;
  16. import android.widget.Toast;
  18. import com.happy.R;
  19. import com.happy.core.BaseNativeActivity;
  20. import com.happy.core.NativeFlutterActivity;
  21. import com.happy.utils.AppUtils;
  23. import java.io.BufferedInputStream;
  24. import java.io.BufferedOutputStream;
  25. import java.io.File;
  26. import java.io.FileOutputStream;
  27. import java.io.InputStream;
  28. import java.io.OutputStream;
  29. import java.util.Enumeration;
  30. import java.util.zip.ZipEntry;
  31. import java.util.zip.ZipFile;
  33. import io.flutter.util.PathUtils;
  35. public class UpdateActivity extends BaseNativeActivity implements View.OnClickListener {
  37.     private static final String TAG = "UpdateFlutterActivity";
  38.     private static final String FLUTTER_UPDATE_PACKAGE_DIR = "flutter_package";
  39.     private static final String FLUTTER_UPDATE_PACKAGE_NAME = "Flutter-package.zip";
  40.     private static final String FLUTTER_UPDATE_PACKAGE_LOCAL_ZIP_FILE = Environment.getExternalStorageDirectory().getAbsolutePath()+ File.separator + FLUTTER_UPDATE_PACKAGE_DIR + File.separator + FLUTTER_UPDATE_PACKAGE_NAME;
  41.     private static final String FLUTTER_UPDATE_PACKAGE_LOCAL_FILE_DIR = Environment.getExternalStorageDirectory().toString() + File.separator + "happy_flutter_update" + File.separator;
  43.     private Button btnUpdate;
  44.     private Button btnPage;
  45.     private CompleteReceiver mDownloadCompleteReceiver = new CompleteReceiver();
  47.     @Override
  48.     protected void onCreate(Bundle savedInstanceState) {
  49.         super.onCreate(savedInstanceState);
  50.         setContentView(R.layout.activity_update);
  51.         setActionToolBar();
  53.         btnUpdate = findViewById(R.id.btn_update);
  54.         btnPage = findViewById(R.id.btn_page);
  55.         btnUpdate.setOnClickListener(this);
  56.         btnPage.setOnClickListener(this);
  58.         registerReceiver(mDownloadCompleteReceiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
  59.     }
  61.     @Override
  62.     public void onClick(View v) {
  63.         switch (v.getId()) {
  64.             case R.id.btn_update:
  65.                 checkPermission();
  66.                 break;
  67.             case R.id.btn_page:
  68.                 Intent intent = new Intent(this, NativeFlutterActivity.class);
  69.                 intent.setAction(Intent.ACTION_RUN);
  70.                 intent.putExtra("route", "flutter://test/update");
  71.                 startActivity(intent);
  72.                 break;
  73.         }
  74.     }
  76.     private void onFlutterUpdatePackageDownLoaded() throws Exception {
  77.         final File file = new File(FLUTTER_UPDATE_PACKAGE_LOCAL_ZIP_FILE);
  78.         if (file == null || !file.exists()) {
  79.             Log.i(TAG, "flutter package file download error, check URL or network state");
  80.             return;
  81.         }
  82.         File fileDir = new File(FLUTTER_UPDATE_PACKAGE_LOCAL_FILE_DIR);
  83.         if (!fileDir.exists()) {
  84.             fileDir.mkdirs();
  85.         }
  86.         ZipFile zipFile = new ZipFile(FLUTTER_UPDATE_PACKAGE_LOCAL_ZIP_FILE);
  87.         Enumeration zipList = zipFile.entries();
  88.         ZipEntry zipEntry;
  89.         byte[] buffer = new byte[1024];
  90.         while (zipList.hasMoreElements()) {
  91.             zipEntry = (ZipEntry) zipList.nextElement();
  92.             if (zipEntry.isDirectory()) {
  93.                 String destPath = FLUTTER_UPDATE_PACKAGE_LOCAL_FILE_DIR + zipEntry.getName();
  94.                 File dir = new File(destPath);
  95.                 dir.mkdirs();
  96.                 continue;
  97.             }
  98.             OutputStream out = new BufferedOutputStream(new FileOutputStream(new File(FLUTTER_UPDATE_PACKAGE_LOCAL_FILE_DIR + zipEntry.getName())));
  99.             InputStream is = new BufferedInputStream(zipFile.getInputStream(zipEntry));
  101.             int len;
  102.             while ((len = is.read(buffer)) != -1) {
  103.                 out.write(buffer, 0, len);
  104.             }
  105.             out.flush();
  106.             out.close();
  107.             is.close();
  108.         }
  109.         zipFile.close();
  110.     }
  112.     public void copyToDataFlutterAssets() throws Exception {
  113.         // String destPath = PathUtils.getDataDirectory(this.getApplicationContext()) + File.separator + "flutter_assets/";
  114.         String destPath = PathUtils.getDataDirectory(this.getApplicationContext()) + File.separator;
  115.         File[] files = new File(FLUTTER_UPDATE_PACKAGE_LOCAL_FILE_DIR).listFiles();
  116.         for (File file : files) {
  117.             if (file.getPath().contains("isolate_snapshot_data")
  118.                     || file.getPath().contains("isolate_snapshot_instr")
  119.                     || file.getPath().contains("vm_snapshot_data")
  120.                     || file.getPath().contains("vm_snapshot_instr")) {
  121.                 AppUtils.copyFile(file.getPath(), destPath + File.separator + file.getName());
  122.             }
  123.         }
  124.         Toast.makeText(this, "更新包更新成功", Toast.LENGTH_LONG).show();
  125.     }
  127.     private class CompleteReceiver extends BroadcastReceiver  {
  129.         @Override
  130.         public void onReceive(Context context, Intent intent) {
  131.             if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(intent.getAction())) {
  132.                 try {
  133.                     Toast.makeText(UpdateActivity.this, "更新包下载成功", Toast.LENGTH_LONG).show();
  134.                     onFlutterUpdatePackageDownLoaded();
  135.                     copyToDataFlutterAssets();
  136.                 } catch (Exception e) {
  137.                     e.printStackTrace();
  138.                 }
  139.             } else {
  141.             }
  142.         }
  143.     }
  145.     private void deleteFlutterPackage() {
  146.         File zipFile = new File(FLUTTER_UPDATE_PACKAGE_LOCAL_ZIP_FILE);
  147.         if (zipFile.exists()) {
  148.             zipFile.delete();
  149.         }
  150.         File dir = new File(FLUTTER_UPDATE_PACKAGE_LOCAL_FILE_DIR);
  151.         if (dir.isDirectory()) {
  152.            for (File file : dir.listFiles()) {
  153.                if (file.exists()) {
  154.                    file.delete();
  155.                }
  156.            }
  157.         }
  158.     }
  160.     private void downloadFlutterUpdatePackage(String url) {
  161.         DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
  162.         request.setTitle("Flutter动态更新");
  163.         request.setDescription("Flutter动态更新包下载");
  164.         request.setAllowedOverRoaming(false);
  165.         request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
  166.         request.setDestinationInExternalPublicDir(FLUTTER_UPDATE_PACKAGE_DIR, FLUTTER_UPDATE_PACKAGE_NAME);
  167.         // request.setDestinationUri(Uri.fromFile(new File(FLUTTER_UPDATE_PACKAGE_LOCAL_ZIP_FILE)));
  168.         DownloadManager dm = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
  169.         dm.enqueue(request);
  170.     }
  172.     private void startDownLoadFlutterPackage() {
  173.         deleteFlutterPackage();
  174.         String url = getFlutterUpdatePackageUrl(this);
  175.         downloadFlutterUpdatePackage(url);
  176.     }
  178.     private void checkPermission() {
  179.         if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED
  180.                 && ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
  181.             startDownLoadFlutterPackage();
  182.         } else {
  183.             ActivityCompat.requestPermissions(this, new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE }, 1000);
  184.         }
  185.     }
  187.     @Override
  188.     public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
  189.         switch (requestCode) {
  190.             case 1000: {
  191.                 if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED &&  grantResults[1] == PackageManager.PERMISSION_GRANTED) {
  192.                     startDownLoadFlutterPackage();
  193.                 }
  194.             }
  196.         }
  197.     }
  199.     private static String getFlutterUpdatePackageUrl(Context context) {
  200.         if (AppUtils.isApkInDebug(context)) {
  201.             return "https://xxxx/flutter-update-debug.zip";
  202.         }
  203.          return "https://xxxx/flutter-update-release.zip";
  204.     }
  205. }

Android 动态更新效果演示

flutter_update.mp4 (1.36MB)