从USB移动存储读取文件 [英] read file from usb removable storage
本文介绍了从USB移动存储读取文件的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
在我的应用程序中,我想从USB可移动存储中读取文件 我有一个.txt,我想阅读
in my application I want to read a file from usb removable storage I have a.txt and i want to read it
void read() {
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = manager.getDeviceList();
Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
StringBuffer sb = new StringBuffer();
while (deviceIterator.hasNext()) {
UsbDevice device = deviceIterator.next();
String Model = device.getDeviceName();
try {
File file = new File(Model + "/a.txt");
if (file.exists())
Toast.makeText(getApplicationContext(), "Exist", Toast.LENGTH_LONG).show();
else
Toast.makeText(getApplicationContext(), "Not Exist", Toast.LENGTH_LONG).show();
BufferedReader br = new BufferedReader(new FileReader(Model + "/a.txt"));
String sCurrentLine;
while ((sCurrentLine = br.readLine()) != null) {
textView.append(sCurrentLine + "\n");
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_LONG).show();
}
}
}
当检查文件存在时返回false,并且在打开和读取文件时抛出异常
when check file exists return false and when opening and reading file throw exception
java.io.filenotfoundexception :/dev/bus/001/002/a.txt: opent failed : EACCES (permission denied)
在清单中有
<uses-permission android:name="android.permission.USB_PERMISSION" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_MEDIA_STORAGE" />
推荐答案
没有一个解决方案对我有用 我搜索并找到了这个库
none of this solution worked for me I searched and found this library
开放源代码库,无需在设备上生根即可访问Android上的USB Mass Storage设备
为我测试并工作
这篇关于从USB移动存储读取文件的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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