Android P PackageInstaller 学习

总体而言， Android P 和 Android O相比，PackageInstaller模块变化不大。因为Android O的时候没来及总结，所以一些 Android O上就出现的特性也会在这里记录学习一下。

界面跳转流程

Android P PackageInstaller.png

  从界面跳转流程上看，与 Android O相比，多了一个 DeleteStagedFileOnResult 页面，主要就是把原来 跳转PackageInstallerActivity 和删除 临时文件的动作 拎到这里来了。

一些重要的点

• Android O开始，三方应用如果想调起 系统 PackageInstaller 安装/卸载应用，必须在AndroidManifest中声明对应的权限:

    
    '

否则无法实现安装会有类似 log打出来：

10-26 16:26:25.188  7457  7457 E InstallStart: Requesting uid 10106 needs to declare permission android.permission.REQUEST_INSTALL_PACKAGES

看一看这一部分的检测逻辑，代码位置在 InstallStart.java的 oncreate方法中

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        .............
        .............
        final ApplicationInfo sourceInfo = getSourceInfo(callingPackage);
        final int originatingUid = getOriginatingUid(sourceInfo);
        /**
         * 下面是判定  未知来源  的逻辑
         */
        boolean isTrustedSource = false;
        //如果是 priv-app, 就去看Intent中 EXTRA_NOT_UNKNOWN_SOURCE 参数，也就是说，如果调起安装器的不是priv-app, 带不带这个参数都没用
        //如果是 priv-app, 再看 EXTRA_NOT_UNKNOWN_SOURCE 参数的值
        if (sourceInfo != null
                && (sourceInfo.privateFlags & ApplicationInfo.PRIVATE_FLAG_PRIVILEGED) != 0) {
            isTrustedSource = intent.getBooleanExtra(Intent.EXTRA_NOT_UNKNOWN_SOURCE, false);
        }

        if (!isTrustedSource && originatingUid != PackageInstaller.SessionParams.UID_UNKNOWN) {
            final int targetSdkVersion = getMaxTargetSdkVersionForUid(this, originatingUid);
            if (targetSdkVersion < 0) {
                Log.w(LOG_TAG, "Cannot get target sdk version for uid " + originatingUid);
                // Invalid originating uid supplied. Abort install.
                mAbortInstall = true;
            } else if (targetSdkVersion >= Build.VERSION_CODES.O && !declaresAppOpPermission(
                    //在 Android O 及以上版本中，调起安装器需要声明REQUEST_INSTALL_PACKAGES  权限，否则直接放弃安装
                    originatingUid, Manifest.permission.REQUEST_INSTALL_PACKAGES)) {
                Log.e(LOG_TAG, "Requesting uid " + originatingUid + " needs to declare permission "
                        + Manifest.permission.REQUEST_INSTALL_PACKAGES);
                mAbortInstall = true;
            }
        }
        if (mAbortInstall) {
            setResult(RESULT_CANCELED);
            finish();
            return;
        }

        Intent nextActivity = new Intent(intent);
        nextActivity.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);

        // The the installation source as the nextActivity thinks this activity is the source, hence
        // set the originating UID and sourceInfo explicitly
        nextActivity.putExtra(PackageInstallerActivity.EXTRA_CALLING_PACKAGE, callingPackage);
        nextActivity.putExtra(PackageInstallerActivity.EXTRA_ORIGINAL_SOURCE_INFO, sourceInfo);
        nextActivity.putExtra(Intent.EXTRA_ORIGINATING_UID, originatingUid);

        if (PackageInstaller.ACTION_CONFIRM_PERMISSIONS.equals(intent.getAction())) {
            nextActivity.setClass(this, PackageInstallerActivity.class);
        } else {
            Uri packageUri = intent.getData();

            /*
            几种类型的Uri, file,content,package, 不同的Uri跳转到不同的Activity
             */
            if (packageUri != null && (packageUri.getScheme().equals(ContentResolver.SCHEME_FILE)
                    || packageUri.getScheme().equals(ContentResolver.SCHEME_CONTENT))) {
                // Copy file to prevent it from being changed underneath this process
                nextActivity.setClass(this, InstallStaging.class);
            } else if (packageUri != null && packageUri.getScheme().equals(
                    PackageInstallerActivity.SCHEME_PACKAGE)) {
                nextActivity.setClass(this, PackageInstallerActivity.class);
            } else {
                Intent result = new Intent();
                result.putExtra(Intent.EXTRA_INSTALL_RESULT,
                        PackageManager.INSTALL_FAILED_INVALID_URI);
                setResult(RESULT_FIRST_USER, result);

                nextActivity = null;
            }
        }

        if (nextActivity != null) {
            startActivity(nextActivity);
        }
        finish();
    }

• Android O上去除了 未知来源 总开关，改为单个渠道控制 未知来源的 安装请求。

  
  
  9833687_5.png
  
  

  这一部分检测逻辑如下，代码位置在 PackageInstallerActivity.java

    private void handleUnknownSources() {
        if (mOriginatingPackage == null) {
            Log.i(TAG, "No source found for package " + mPkgInfo.packageName);
            showDialogInner(DLG_ANONYMOUS_SOURCE);
            return;
        }
        /**
         * 检查callingPackage是否具有REQUEST_INSTALL_PACKAGES权限，如果 权限标志位 是 AppOpsManager.MODE_ERRORED,
         * 就显示 渠道未知来源对话框，可以进入设置中设置开关
         */
        // Shouldn't use static constant directly, see b/65534401.
        final int appOpCode =
                AppOpsManager.permissionToOpCode(Manifest.permission.REQUEST_INSTALL_PACKAGES);
        final int appOpMode = mAppOpsManager.noteOpNoThrow(appOpCode,
                mOriginatingUid, mOriginatingPackage);
        switch (appOpMode) {
            case AppOpsManager.MODE_DEFAULT:
                try {
                    int result = mIpm.checkUidPermission(
                            Manifest.permission.REQUEST_INSTALL_PACKAGES, mOriginatingUid);
                    if (result == PackageManager.PERMISSION_GRANTED) {
                        initiateInstall();
                        break;
                    }
                } catch (RemoteException exc) {
                    Log.e(TAG, "Unable to talk to package manager");
                }
                mAppOpsManager.setMode(appOpCode, mOriginatingUid,
                        mOriginatingPackage, AppOpsManager.MODE_ERRORED);
                // fall through
                //渠道未知来源对话框
            case AppOpsManager.MODE_ERRORED:
                showDialogInner(DLG_EXTERNAL_SOURCE_BLOCKED);
                break;
            case AppOpsManager.MODE_ALLOWED:
                initiateInstall();
                break;
            default:
                Log.e(TAG, "Invalid app op mode " + appOpMode
                        + " for OP_REQUEST_INSTALL_PACKAGES found for uid " + mOriginatingUid);
                finish();
                break;
        }
    }