java如何在安卓 10和安卓 11中扫描/加载来自内部和外部存储的所有文件
在安卓 10和安卓 11中，如何从内部和外部存储加载所有文件。实际上，我想在我的应用程序中加载一个特定的扩展名文件（即.pdf，txt），该扩展名文件保存在内部或外部存储器中
我使用了下面的代码，它在安卓 8.1 API级别26之前运行良好
我从internet获取了StorageUtil类，它将加载所有可能的物理路径
public class StorageUtil {
// Primary physical SD-CARD (not emulated)
private static final String EXTERNAL_STORAGE = System.getenv("EXTERNAL_STORAGE");
// All Secondary SD-CARDs (all exclude primary) separated by File.pathSeparator, i.e: ":", ";"
private static final String SECONDARY_STORAGES = System.getenv("SECONDARY_STORAGE");
// Primary emulated SD-CARD
private static final String EMULATED_STORAGE_TARGET = System.getenv("EMULATED_STORAGE_TARGET");
// PhysicalPaths based on phone model
@SuppressLint("SdCardPath")
@SuppressWarnings("SpellCheckingInspection")
private static final String[] KNOWN_PHYSICAL_PATHS = new String[]{
"/storage/sdcard0",
"/storage/sdcard1", //Motorola Xoom
"/storage/extsdcard", //Samsung SGS3
"/storage/sdcard0/external_sdcard", //User request
"/mnt/extsdcard",
"/mnt/sdcard/external_sd", //Samsung galaxy family
"/mnt/sdcard/ext_sd",
"/mnt/external_sd",
"/mnt/media_rw/sdcard1", //4.4.2 on CyanogenMod S3
"/removable/microsd", //Asus transformer prime
"/mnt/emmc",
"/storage/external_SD", //LG
"/storage/ext_sd", //HTC One Max
"/storage/removable/sdcard1", //Sony Xperia Z1
"/data/sdext",
"/data/sdext2",
"/data/sdext3",
"/data/sdext4",
"/sdcard1", //Sony Xperia Z
"/sdcard2", //HTC One M8s
"/storage/microsd" //ASUS ZenFone 2
};
/**
* Returns all available storages in the system (include emulated)
* <p/>
* Warning: Hack! Based on Android source code of version 4.3 (API 18)
* Because there is no standard way to get it.
*
* @return paths to all available storages in the system (include emulated)
*/
public static String[] getStorageDirectories(Context context) {
// Final set of paths
final Set<String> availableDirectoriesSet = new HashSet<>();
if (!TextUtils.isEmpty(EMULATED_STORAGE_TARGET)) {
// Device has an emulated storage
availableDirectoriesSet.add(getEmulatedStorageTarget());
} else {
// Device doesn't have an emulated storage
availableDirectoriesSet.addAll(getExternalStorage(context));
}
// Add all secondary storages
Collections.addAll(availableDirectoriesSet, getAllSecondaryStorages());
String[] storagesArray = new String[availableDirectoriesSet.size()];
return availableDirectoriesSet.toArray(storagesArray);
}
private static Set<String> getExternalStorage(Context context) {
final Set<String> availableDirectoriesSet = new HashSet<>();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
// Solution of empty raw emulated storage for 安卓 version >= marshmallow
// because the EXTERNAL_STORAGE become something like: "/Storage/A5F9-15F4",
// so we can't access it directly
File[] files = getExternalFilesDirs(context, null);
for (File file : files) {
if (file != null) {
String applicationSpecificAbsolutePath = file.getAbsolutePath();
String rootPath = applicationSpecificAbsolutePath.substring(
0,
applicationSpecificAbsolutePath.indexOf("Android/data")
);
availableDirectoriesSet.add(rootPath);
}
}
} else {
if (TextUtils.isEmpty(EXTERNAL_STORAGE)) {
availableDirectoriesSet.addAll(getAvailablePhysicalPaths());
} else {
// Device has physical external storage; use plain paths.
availableDirectoriesSet.add(EXTERNAL_STORAGE);
}
}
return availableDirectoriesSet;
}
private static String getEmulatedStorageTarget() {
String rawStorageId = "";
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
// External storage paths should have storageId in the last segment
// i.e: "/storage/emulated/storageId" where storageId is 0, 1, 2, ...
final String path = Environment.getExternalStorageDirectory().getAbsolutePath();
final String[] folders = path.split(File.separator);
final String lastSegment = folders[folders.length - 1];
if (!TextUtils.isEmpty(lastSegment) && TextUtils.isDigitsOnly(lastSegment)) {
rawStorageId = lastSegment;
}
}
if (TextUtils.isEmpty(rawStorageId)) {
return EMULATED_STORAGE_TARGET;
} else {
return EMULATED_STORAGE_TARGET + File.separator + rawStorageId;
}
}
private static String[] getAllSecondaryStorages() {
if (!TextUtils.isEmpty(SECONDARY_STORAGES)) {
// All Secondary SD-CARDs split into array
return SECONDARY_STORAGES.split(File.pathSeparator);
}
return new String[0];
}
/**
* Filter available physical paths from known physical paths
*
* @return List of available physical paths from current device
*/
private static List<String> getAvailablePhysicalPaths() {
List<String> availablePhysicalPaths = new ArrayList<>();
for (String physicalPath : KNOWN_PHYSICAL_PATHS) {
File file = new File(physicalPath);
if (file.exists()) {
availablePhysicalPaths.add(physicalPath);
}
}
return availablePhysicalPaths;
}
/**
* Returns absolute paths to application-specific directories on all
* external storage devices where the application can place persistent files
* it owns. These files are internal to the application, and not typically
* visible to the user as media.
* <p>
* This is like {@link Context#getFilesDir()} in that these files will be
* deleted when the application is uninstalled, however there are some
* important differences:
* <ul>
* <li>External files are not always available: they will disappear if the
* user mounts the external storage on a computer or removes it.
* <li>There is no security enforced with these files.
* </ul>
* <p>
* External storage devices returned here are considered a permanent part of
* the device, including both emulated external storage and physical media
* slots, such as SD cards in a battery compartment. The returned paths do
* not include transient devices, such as USB flash drives.
* <p>
* An application may store data on any or all of the returned devices. For
* example, an app may choose to store large files on the device with the
* most available space, as measured by {@link 安卓.os.StatFs}.
* <p>
* Starting in {@link Build.VERSION_CODES#KITKAT}, no permissions
* are required to write to the returned paths; they're always accessible to
* the calling app. Before then,
* {@link 安卓.Manifest.permission#WRITE_EXTERNAL_STORAGE} is required to
* write. Write access outside of these paths on secondary external storage
* devices is not available. To request external storage access in a
* backwards compatible way, consider using {@code 安卓:maxSdkVersion}
* like this:
*
* <pre class="prettyprint"><uses-permission
* 安卓:name="安卓.permission.WRITE_EXTERNAL_STORAGE"
* 安卓:maxSdkVersion="18" /></pre>
* <p>
* The first path returned is the same as
* {@link Context#getExternalFilesDir(String)}. Returned paths may be
* {@code null} if a storage device is unavailable.
*
* @see Context#getExternalFilesDir(String)
*/
private static File[] getExternalFilesDirs(Context context, String type) {
if (Build.VERSION.SDK_INT >= 19) {
return context.getExternalFilesDirs(type);
} else {
return new File[]{context.getExternalFilesDir(type)};
}
}
和loadDirectoryFiles函数，该函数将加载特定目录中的所有文件
object LoadDirectory {
fun loadDirectoryFiles(directory: File) {
try {
val fileList: Array<File> = directory.listFiles()
if (fileList.isNotEmpty()) {
for (i in fileList.indices) {
if (fileList[i].isDirectory) {
loadDirectoryFiles(fileList[i])
} else {
val name: String = fileList[i].name.toLowerCase(Locale.getDefault())
//Now look for desired extension
if (name.endsWith(Constants.PDF_EXTENSION)) {
Constants.allFileList.add(fileList[i])
}
}
}
}
}
catch (e : Exception){
Log.d("TAG","Error: ${e.message} and directory: ${directory.absoluteFile}")
}
}
}
这里是它的用法
val storagePaths = StorageUtil.getStorageDirectories(this)
for (path in storagePaths) {
val storageFile = File(path)
LoadDirectory.loadDirectoryFiles(storageFile)
}
以上代码在安卓8.1上运行良好，但在安卓8.1上不起作用，现在如何通过从内部和外部存储加载特定扩展名（即pdf）文件来实现这一点
提前谢谢你帮助我
共 (0) 个答案