[英]How to read OTG USB storage
I want to read/write OTG USB storage from device.我想从设备读取/写入 OTG USB 存储设备。 For that I have written the code below but it shows only the SD card.
为此,我编写了下面的代码,但它只显示了 SD 卡。
HashSet<String> out = new HashSet<String>();
String reg = "(?i).*vold.*(vfat|ntfs|exfat|fat32|ext3|ext4).*rw.*";
String s = "";
try {
final Process process = new ProcessBuilder().command("mount")
.redirectErrorStream(true).start();
process.waitFor();
final InputStream is = process.getInputStream();
final byte[] buffer = new byte[1024];
while (is.read(buffer) != -1) {
s = s + new String(buffer);
}
is.close();
} catch (final Exception e) {
e.printStackTrace();
}
// parse output
final String[] lines = s.split("\n");
for (String line : lines) {
if (!line.toLowerCase(Locale.US).contains("asec")) {
if (line.matches(reg)) {
String[] parts = line.split(" ");
for (String part : parts) {
if (part.startsWith("/"))
if (!part.toLowerCase(Locale.US).contains("vold"))
out.add(part);
}
}
}
}
for (String s3 : out ) {
Toast.makeText(getApplicationContext(),s3,Toast.LENGTH_LONG).show();
System.out.println("Value: " +s3);
}
With the code above I am able to get external SD card but not able to read USB with OTG.使用上面的代码,我可以获得外部 SD 卡,但无法使用 OTG 读取 USB。
How can I get USB storage also?我怎样才能获得 USB 存储设备?
I've looked at your other questions regarding OTG access, and I think you're making it hard on yourself.我已经查看了您关于 OTG 访问的其他问题,我认为您对自己太苛刻了。 The easiest way IMO to access/read/write OTG on a very wide range of devices is by querying all these directories, and using shell to read/write to them:
IMO 在非常广泛的设备上访问/读取/写入 OTG 的最简单方法是查询所有这些目录,并使用 shell 读取/写入它们:
/storage/UsbDriveA (all Samsung devices)
/storage/USBstorage1 (LG G4, V10, G3, G2, other LG devices)
/storage/usbdisk (Moto Maxx, Turbo 2, Moto X Pure, other Motorola devices)
/storage/usbotg (Sony Xperia devices, Lenovo Tabs)
/storage/UDiskA (Oppo devices)
/storage/usb-storage (Acer Iconia Tabs)
/storage/usbcard (Dell Venue -- Vanilla Android 4.3 tablet)
/storage/usb (HTC One M7, and some Vanilla Android devices)
Tested on my collection of devices (and a few others'), and a quick trip to Bestbuy for testing the latest flagships.在我收集的设备(和其他一些设备)上进行了测试,并快速前往 Bestbuy 测试最新的旗舰产品。 The only popular devices I know I'm missing are Hawuei/Xioami devices based in China, which are becoming popular in English countries.
我知道我缺少的唯一流行设备是位于中国的 Hawuei/小米设备,它们在英国国家/地区越来越流行。
You would be using Runtime.exec()
or ProcessBuilder
and testing the length of the ls
command output on each directory (to find the mounted USB directory), and cp
or redirection >
to write files to the pendrive, and cat
to read off the pendrive.您将使用
Runtime.exec()
或ProcessBuilder
并测试每个目录上ls
命令输出的长度(以查找安装的 USB 目录),并使用cp
或重定向>
将文件写入随身碟,并使用cat
读取随身碟。
Hope this helps希望这可以帮助
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