android.os.Environment#getExternalStorageDirectory ( )源码实例Demo

public void exportToFile() throws IOException {
    List<Favorite> all = read();
    String json = JsonUtil.toJson(all);
    File file = new File(Environment.getExternalStorageDirectory(), "androidweeklyfavorite.json");
    if (!file.exists()) {
        file.createNewFile();
    }
    FileWriter fileWriter = null;
    try {
        fileWriter = new FileWriter(file);
        fileWriter.write(json);
        fileWriter.flush();
    } finally {
        IOUtil.close(fileWriter);
    }
}
 

/**
 * 创建一个拍照图片文件对象
 */
@SuppressWarnings("ResultOfMethodCallIgnored")
private static File createCameraFile() {
    File folder = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), "Camera");
    if (!folder.exists() || !folder.isDirectory()) {
        if (!folder.mkdirs()) {
            folder = Environment.getExternalStorageDirectory();
        }
    }

    try {
        File file = new File(folder, "IMG_" + new SimpleDateFormat("yyyyMMdd_kkmmss", Locale.getDefault()).format(new Date()) + ".jpg");
        file.createNewFile();
        return file;
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}
 

/**
 * Determine if a file or directory exists.
 * @param name				The name of the file to check.
 * @return					T=exists, F=not found
 */
public static boolean testFileExists(String name) {
    boolean status;

    // If SD card exists
    if ((testSaveLocationExists()) && (!name.equals(""))) {
        File path = Environment.getExternalStorageDirectory();
        File newPath = constructFilePaths(path.toString(), name);
        status = newPath.exists();
    }
    // If no SD card
    else {
        status = false;
    }
    return status;
}
 

public FileAccess(String fileName) {

		root = Environment.getExternalStorageDirectory();
		file = new File(root, fileName);
		try {
			Log.d("plik", file.toString());
			filewriter = new FileWriter(file);
			out = new BufferedWriter(filewriter);
			Log.d("plik", "fileAccess OK");
		} catch (IOException e) {

			Log.d("plik", "fileAccess ERR");
			// Toast.makeText(context, "Can't write to file",
			// Toast.LENGTH_LONG).show();
		}

	}
 

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if (savedInstanceState != null) {
        mCurrentDir = (File) savedInstanceState.getSerializable(STATE_CURRENT_DIR);
    }
    else {
        mCurrentDir = Environment.getExternalStorageDirectory();
    }

    getActivity().setTitle(R.string.menu_browser);
}
 

public void importFromFile() throws IOException {
    File file = new File(Environment.getExternalStorageDirectory(), "androidweeklyfavorite.json");
    String json = IOUtil.read(file);
    List<Favorite> favorites = JsonUtil.fromJson(json, new TypeToken<List<Favorite>>() {
    }.getType());
    if (favorites != null) {
        for (Favorite favorite : favorites) {
            save(favorite);
        }
    }
}
 

private void startFileWrite () {
	final File file = new File(Environment.getExternalStorageDirectory(),
			FILTERS_FILE_PREFIX
			+ DateHelper.standardDateTimeFormat().format(new Date())
			+ FILTERS_FILE_EXT);
	new FileWriteTask(FiltersPrefFragment.this, getPrefs(), file).execute();
}
 

public static File getSDParentDir() throws IOException{
	if (isSDCardExist()){
		File file = new File(Environment.getExternalStorageDirectory() + File.separator + "HuoCheXing");
		if (!file.exists()){
			file.mkdir();
		}
		return file;
	}
	return null;
}
 

public void fix(View view) {
    File patchFile = new File(Environment.getExternalStorageDirectory(), "fix.apk");
    if (!patchFile.exists()) {
        Toast.makeText(this, "hotfix file not exist!", Toast.LENGTH_SHORT).show();
        return;
    }
    File optDir = new File(this.getFilesDir(), "fix_opt");
    optDir.mkdirs();
    new Aceso().installPatch(optDir, patchFile);
}
 

/**
 * Checks if there is enough Space on SDCard
 *
 * @param updateSize size to Check (long)
 * @return <code>true</code> if the Update will fit on SDCard, <code>false</code> if not enough
 * space on SDCard. Will also return <code>false</code>, if the SDCard is not mounted as
 * read/write
 */
public boolean hasEnoughSpaceOnSdCard(long updateSize)
{
    RootTools.log("Checking SDcard size and that it is mounted as RW");
    String status = Environment.getExternalStorageState();
    if (!status.equals(Environment.MEDIA_MOUNTED))
    {
        return false;
    }
    File path = Environment.getExternalStorageDirectory();
    StatFs stat = new StatFs(path.getPath());
    long blockSize = stat.getBlockSize();
    long availableBlocks = stat.getAvailableBlocks();
    return (updateSize < availableBlocks * blockSize);
}
 

private boolean exportWallet(Activity c, boolean already) {
    if (walletToExport == null)
        return false;
    if (walletToExport.startsWith("0x"))
        walletToExport = walletToExport.substring(2);

    if (ExternalStorageHandler.hasPermission(c)) {
        File folder = new File(Environment.getExternalStorageDirectory(), "Lunary");
        if (!folder.exists())
            folder.mkdirs();

        File storeFile = new File(folder, walletToExport + ".json");
        try {
            copyFile(new File(c.getFilesDir(), walletToExport), storeFile);
        } catch (IOException e) {
            return false;
        }

        // fix, otherwise won't show up via USB
        Intent mediaScannerIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
        Uri fileContentUri = Uri.fromFile(storeFile); // With 'permFile' being the File object
        mediaScannerIntent.setData(fileContentUri);
        c.sendBroadcast(mediaScannerIntent); // With 'this' being the context, e.g. the activity
        return true;
    } else if (!already) {
        ExternalStorageHandler.askForPermission(c);
        return exportWallet(c, true);
    } else {
        return false;
    }
}
 

/**
 * {@inheritDoc}
 */
@Override
public void service(final HttpServletRequest request, final HttpServletResponse response) throws ServletException {
    ServerConfig serverConfig = (ServerConfig) getServletContext().getAttribute(ServerConfig.class.getName());

    HTMLDocument doc = new HTMLDocument("Drive Access");
    doc.setOwnerClass(getClass().getSimpleName());

    doc.writeln("<div class=\"page-header\"><h1>Drive Access</h1></div>");

    if (!serverConfig.getAttribute(ADMIN_DRIVE_ACCESS_ENABLED).equals(ServerConfigImpl.TRUE)) {
        renderFunctionDisabled(response, doc);
        return;
    }

    String path = StringUtilities.urlDecode(request.getQueryString());

    if ("".equals(path)) {
        path = "/";
    }

    renderBreadcrubms(doc, path);

    File file = new File(Environment.getExternalStorageDirectory() + path);

    if (file.exists() && file.isDirectory()) {
        renderDirectoryList(doc, path, file);
    } else {
        renderPathNotAvailable(doc);
    }

    response.getWriter().print(doc.toString());
}
 

/**
 * ��ȡSD���Ŀ��ÿռ�
 * @param view
 */
public void space(View view){
	File file = Environment.getExternalStorageDirectory();
	long size = file.getFreeSpace(); //byte
	String formatFileSize = Formatter.formatFileSize(this, size);
	
	Toast.makeText(this, formatFileSize, 0).show();
}
 

@Override
public void onCreate(Bundle bdl) {
    super.onCreate(bdl);
    PermissionUtils.get(this).needStorage(this);
    setContentView(R.layout.settings_backuprestore);
    ListView list = findViewById(R.id.listView1);
    mFolder = new File(Environment.getExternalStorageDirectory(), "backups/com.metinkale.prayer");
    mFolder.mkdirs();
    mAdapter = new MyAdapter(this);
    list.setAdapter(mAdapter);
    list.setOnItemClickListener(this);
}
 

public static void createSDCardDir(boolean isCreateVideoDir) {
	if (Environment.MEDIA_MOUNTED.equals(Environment
			.getExternalStorageState())) {
		File sdcardDir = Environment.getExternalStorageDirectory();
		String path = sdcardDir.getPath() + VIDEO_THUMB_PATH;
		File path1 = new File(path);
		if (!path1.exists()) {
			path1.mkdirs();
		}
	}
}
 

public static Boolean saveImage(String url, Context context) {
        boolean flag = false;
        try {
            // 获取 bitmap
            Bitmap bitmap = Glide.with(context).asBitmap().load(url)
                    .submit(Target.SIZE_ORIGINAL, Target.SIZE_ORIGINAL)
                    .get();
            // http://stormzhang.com/android/2014/07/24/android-save-image-to-gallery/
            if (bitmap != null) {
                // 首先保存图片
                File appDir = new File(Environment.getExternalStorageDirectory(), "Toutiao");
                if (!appDir.exists()) {
                    appDir.mkdir();
                }
                String fileName = System.currentTimeMillis() + ".jpg";
                File file = new File(appDir, fileName);
                FileOutputStream fos = new FileOutputStream(file);
                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
                fos.flush();
                fos.close();

                // 其次把文件插入到系统图库
//                MediaStore.Images.Media.insertImage(InitApp.AppContext.getContentResolver(), file.getAbsolutePath(), fileName, null);
                // 最后通知图库更新
                context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://" + path)));

                flag = true;
            }
        } catch (InterruptedException | ExecutionException | IOException e) {
            ErrorAction.print(e);
            return false;
        }
        return flag;
    }
 

@Override
public boolean test() throws Throwable {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q && !Environment.isExternalStorageLegacy()) return true;

    if (!TextUtils.equals(Environment.MEDIA_MOUNTED, Environment.getExternalStorageState())) return true;

    File directory = Environment.getExternalStorageDirectory();
    if (!directory.exists()) return true;

    long modified = directory.lastModified();
    String[] pathList = directory.list();
    return modified > 0 && pathList != null;
}
 

public static String getAbsolutePathOnExternalStorage(final Context pContext, final String pFilePath) {
	return Environment.getExternalStorageDirectory() + "/Android/data/" + pContext.getApplicationInfo().packageName + "/files/" + pFilePath;
}
 

private boolean isExternalStoragePath(String filePath) {
    File externalStorageDir = Environment.getExternalStorageDirectory();
    return filePath != null && externalStorageDir != null && filePath.startsWith(externalStorageDir.getPath());
}
 

/**
 * 获取外部存储-根目录
 */
public static File getExternalRootDir() {
    return Environment.getExternalStorageDirectory();
}