Android PackageParser中用XmlResourceParser解析apk包中AndroidManifest.xml

最新推荐文章于 2024-04-15 11:31:49 发布

原创最新推荐文章于 2024-04-15 11:31:49 发布 · 1.1k 阅读

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CC 4.0 BY-SA版权

本文详细介绍了如何使用PackageParser和XmlResourceParser在Android中解析apk包内的AndroidManifest.xml文件，从加载AssetManager到解析应用的各个部分。

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1. PackageParser.parseBaseApk中，定义变量Resources res, XmlResourceParser parser

    private Package parseBaseApk(File apkFile, AssetManager assets, int flags)
            throws PackageParserException {
        final String apkPath = apkFile.getAbsolutePath();


        String volumeUuid = null;
        if (apkPath.startsWith(MNT_EXPAND)) {
            final int end = apkPath.indexOf('/', MNT_EXPAND.length());
            volumeUuid = apkPath.substring(MNT_EXPAND.length(), end);
        }


        mParseError = PackageManager.INSTALL_SUCCEEDED;
        mArchiveSourcePath = apkFile.getAbsolutePath();


        if (DEBUG_JAR) Slog.d(TAG, "Scanning base APK: " + apkPath);


        final int cookie = loadApkIntoAssetManager(assets, apkPath, flags);　　//将apkPath如/system/priv-app/Dialer/Dialer.apk加载进assets资源管理器


        Resources res = null;
        XmlResourceParser parser = null;　　　　　　//变量申名

2. 变量附值, 1中loadApkIntoAssetManager己将数据加载进AssetManager assets

        try {
            res = new Resources(assets, mMetrics, null);   //创建Resources类
            parser = assets.openXmlResourceParser(cookie, ANDROID_MANIFEST_FILENAME);　//资源管理器打开资料中的AndroidManifest.xml数据给解析器parser


            final String[] outError = new String[1];
            final Package pkg = parseBaseApk(apkPath, res, parser, flags, outError);
            if (pkg == null) {
                throw new PackageParserException(mParseError,
                        apkPath + " (at " + parser.getPositionDescription() + "): " + outError[0]);
            }


            pkg.setVolumeUuid(volumeUuid);
            pkg.setApplicationVolumeUuid(volumeUuid);
            pkg.setBaseCodePath(apkPath);
            pkg.setSignatures(null);


            return pkg;


        } catch (PackageParserException e) {
            throw e;
        } catch (Exception e) {
            throw new PackageParserException(INSTALL_PARSE_FAILED_UNEXPECTED_EXCEPTION,
                    "Failed to read manifest from " + apkPath, e);
        } finally {
            IoUtils.closeQuietly(parser);
        }

assets parseMonolithicPackage中定义：


    public Package parseMonolithicPackage(File apkFile, int flags) throws PackageParserException {
        final AssetManager assets = newConfiguredAssetManager();
        final PackageLite lite = parseMonolithicPackageLite(apkFile, flags);
        if (mOnlyCoreApps) {
            if (!lite.coreApp) {
                throw new PackageParserException(INSTALL_PARSE_FAILED_MANIFEST_MALFORMED,
                        "Not a coreApp: " + apkFile);
            }
        }

        try {
            final Package pkg = parseBaseApk(apkFile, assets, flags);
            pkg.setCodePath(apkFile.getAbsolutePath());
            pkg.setUse32bitAbi(lite.use32bitAbi);
            return pkg;
        } finally {
            IoUtils.closeQuietly(assets);
        }
    }

assets创建：

private static AssetManager newConfiguredAssetManager() {
    AssetManager assetManager = new AssetManager();
    assetManager.setConfiguration(0, 0, null, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
            Build.VERSION.RESOURCES_SDK_INT);
    return assetManager;
}

3. 进一步通过parseBaseApk解析，res获取AndroidManifest.xml中属性信息

    private Package parseBaseApk(String apkPath, Resources res, XmlResourceParser parser, int flags,
            String[] outError) throws XmlPullParserException, IOException {
        final String splitName;
        final String pkgName;
......

        final Package pkg = new Package(pkgName);


        TypedArray sa = res.obtainAttributes(parser,
                com.android.internal.R.styleable.AndroidManifest);  //Resources类通过解析器，获取解析数据中的相关R.styleable.AndroidManifest,属性信息sa
        pkg.mVersionCode = pkg.applicationInfo.versionCode = sa.getInteger(
                com.android.internal.R.styleable.AndroidManifest_versionCode, 0); //从属性信息获取相关属性值
        pkg.baseRevisionCode = sa.getInteger(
                com.android.internal.R.styleable.AndroidManifest_revisionCode, 0);
        pkg.mVersionName = sa.getNonConfigurationString(
                com.android.internal.R.styleable.AndroidManifest_versionName, 0);
        if (pkg.mVersionName != null) {
            pkg.mVersionName = pkg.mVersionName.intern();
        }
        pkg.coreApp = parser.getAttributeBooleanValue(null, "coreApp", false);
        sa.recycle();　　//回收sa资源

        return parseBaseApkCommon(pkg, null, res, parser, flags, outError);
    }

4. parser开始解析标签

    private Package parseBaseApkCommon(Package pkg, Set<String> acceptedTags, Resources res,
            XmlResourceParser parser, int flags, String[] outError) throws XmlPullParserException,
            IOException {
        mParseInstrumentationArgs = null;


        int type;
        boolean foundApp = false;

        TypedArray sa = res.obtainAttributes(parser,
                com.android.internal.R.styleable.AndroidManifest);　　//res资源回收后，再重新加载需要资源

        String str = sa.getNonConfigurationString(
                com.android.internal.R.styleable.AndroidManifest_sharedUserId, 0);

......

        int outerDepth = parser.getDepth();
        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT   //当parser解析的不是END_DOCUMENT
                && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
            if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
                continue;
            }

            String tagName = parser.getName();    //获取标签名

            if (acceptedTags != null && !acceptedTags.contains(tagName)) {
                Slog.w(TAG, "Skipping unsupported element under <manifest>: "
                        + tagName + " at " + mArchiveSourcePath + " "
                        + parser.getPositionDescription());
                XmlUtils.skipCurrentTag(parser);
                continue;
            }


            if (tagName.equals(TAG_APPLICATION)) {
                if (foundApp) {
                    if (RIGID_PARSER) {
                        outError[0] = "<manifest> has more than one <application>";
                        mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                        return null;
                    } else {
                        Slog.w(TAG, "<manifest> has more than one <application>");
                        XmlUtils.skipCurrentTag(parser);
                        continue;
                    }
                }
                foundApp = true;
                if (!parseBaseApplication(pkg, res, parser, flags, outError)) { //解析application标签
                    return null;
                }
            } else if (tagName.equals(TAG_OVERLAY)) {

5. parseBaseApplication解析application标签

    private boolean parseBaseApplication(Package owner, Resources res,
            XmlResourceParser parser, int flags, String[] outError)
        throws XmlPullParserException, IOException {
        final ApplicationInfo ai = owner.applicationInfo;
        final String pkgName = owner.applicationInfo.packageName;


        TypedArray sa = res.obtainAttributes(parser,
                com.android.internal.R.styleable.AndroidManifestApplication);


        if (!parsePackageItemInfo(owner, ai, outError,
                "<application>", sa, false /*nameRequired*/,
                com.android.internal.R.styleable.AndroidManifestApplication_name,
                com.android.internal.R.styleable.AndroidManifestApplication_label,
                com.android.internal.R.styleable.AndroidManifestApplication_icon,
                com.android.internal.R.styleable.AndroidManifestApplication_roundIcon,
                com.android.internal.R.styleable.AndroidManifestApplication_logo,
                com.android.internal.R.styleable.AndroidManifestApplication_banner)) {
            sa.recycle();
            mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
            return false;
        }

6. parser解析数据

String nodeName = parser.getName();　　//获取标签名
if (nodeName.equals("action")) {
　　String value = parser.getAttributeValue(
    　　ANDROID_RESOURCES, "name");　　　　//获取action标签中属性为name的值，ANDROID_RESOURCES为域名："http://schemas.android.com/apk/res/android"


    String node_value = parser.nextText();   //获取标签中间的数据