写一个Android遍历SD卡目录找出所有图片文件并将其按照其来源的软件进行分类，且存储在Map<String, List<File>>里，key值为“应用名称+图片”，value值为当前file的代码

以下是一个简单的实现示例：

public Map<String, List<File>> findPicturesByApp(Context context) {
    Map<String, List<File>> picturesByApp = new HashMap<>();

    // 从外部存储器获取SD卡目录
    File sdCardDirectory = Environment.getExternalStorageDirectory();

    // 遍历SD卡目录
    File[] files = sdCardDirectory.listFiles();
    if (files != null) {
        for (File file : files) {
            if (file.isDirectory()) {
                // 如果是目录，则递归遍历子目录
                findPicturesByAppInDirectory(context, file, picturesByApp);
            } else if (isPictureFile(file)) {
                // 如果是图片文件，则将其添加到Map中
                String appName = getAppNameByPackageName(context, getPackageNameByFilePath(file.getAbsolutePath()));
                String key = appName + "图片";
                if (!picturesByApp.containsKey(key)) {
                    picturesByApp.put(key, new ArrayList<File>());
                }
                picturesByApp.get(key).add(file);
            }
        }
    }

    return picturesByApp;
}

private void findPicturesByAppInDirectory(Context context, File directory, Map<String, List<File>> picturesByApp) {
    File[] files = directory.listFiles();
    if (files != null) {
        for (File file : files) {
            if (file.isDirectory()) {
                findPicturesByAppInDirectory(context, file, picturesByApp);
            } else if (isPictureFile(file)) {
                String appName = getAppNameByPackageName(context, getPackageNameByFilePath(file.getAbsolutePath()));
                String key = appName + "图片";
                if (!picturesByApp.containsKey(key)) {
                    picturesByApp.put(key, new ArrayList<File>());
                }
                picturesByApp.get(key).add(file);
            }
        }
    }
}

private boolean isPictureFile(File file) {
    String name = file.getName();
    return name.endsWith(".jpg") || name.endsWith(".jpeg") || name.endsWith(".png") || name.endsWith(".gif");
}

private String getPackageNameByFilePath(String filePath) {
    PackageManager pm = context.getPackageManager();
    List<PackageInfo> packages = pm.getInstalledPackages(PackageManager.GET_ACTIVITIES);
    for (PackageInfo packageInfo : packages) {
        String packagePath = packageInfo.applicationInfo.sourceDir;
        if (filePath.startsWith(packagePath)) {
            return packageInfo.packageName;
        }
    }
    return null;
}

private String getAppNameByPackageName(Context context, String packageName) {
    PackageManager pm = context.getPackageManager();
    ApplicationInfo appInfo = null;
    try {
        appInfo = pm.getApplicationInfo(packageName, PackageManager.GET_META_DATA);
    } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
    }
    if (appInfo != null) {
        return pm.getApplicationLabel(appInfo).toString();
    }
    return null;
}

注释详细，可根据需要进行修改。