Android writes a file to sdcard.

1. Add a function

Try {

File SaveFile = new file ("/sdcard/zhzhg.txt ");

Fileoutputstream outstream = new fileoutputstream (SaveFile );
Try {
Outstream. Write ("file read/write". getbytes ());
}

Catch (ioexception ex)

{
Logger. getlogger (devicelistactivity. Class. getname (). Log (level. Severe, null, ex );
}
Try

{
Outstream. Close ();
}

Catch (ioexception ex)

{
Logger. getlogger (devicelistactivity. Class. getname (). Log (level. Severe, null, ex );
}
}

Catch (filenotfoundexception ex)

{
Logger. getlogger (devicelistactivity. Class. getname (). Log (level. Severe, null, ex );

}

2. Set read and write permissions to the memory card

Add the following content to the androidmainfest. xml file:

<Uses-Permission Android: Name = "android. Permission. write_external_storage"> </uses-Permission>
<Uses-Permission Android: Name = "android. Permission. mount_unmount_filesystems"> </uses-Permission>