android获取未安装APK文件的图标

Drawable getDrawableForMimetype(File file, String mimetype) {
        String PATH_PackageParser = "android.content.pm.PackageParser";
        String PATH_AssetManager = "android.content.res.AssetManager";
        try {
            String apkPath = file.getAbsolutePath();
            Class pkgParserCls = Class.forName(PATH_PackageParser);
            Class[] typeArgs = new Class[1];
            typeArgs[0] = String.class;
            Constructor pkgParserCt = pkgParserCls.getConstructor(typeArgs);
            Object[] valueArgs = new Object[1];
            valueArgs[0] = apkPath;
            Object pkgParser = pkgParserCt.newInstance(valueArgs);
            DisplayMetrics metrics = new DisplayMetrics();
            metrics.setToDefaults();
            typeArgs = new Class[4];
            typeArgs[0] = File.class;
            typeArgs[1] = String.class;
            typeArgs[2] = DisplayMetrics.class;
            typeArgs[3] = Integer.TYPE;
            Method pkgParser_parsePackageMtd = pkgParserCls.getDeclaredMethod("parsePackage", typeArgs);
            valueArgs = new Object[4];
            valueArgs[0] = new File(apkPath);
            valueArgs[1] = apkPath;
            valueArgs[2] = metrics;
            valueArgs[3] = 0;
            Object pkgParserPkg = pkgParser_parsePackageMtd.invoke(pkgParser, valueArgs);
            Field appInfoFld = pkgParserPkg.getClass().getDeclaredField("applicationInfo");
            ApplicationInfo info = (ApplicationInfo) appInfoFld.get(pkgParserPkg);
            Class assetMagCls = Class.forName(PATH_AssetManager);
            Constructor assetMagCt = assetMagCls.getConstructor((Class[]) null);