I'm trying to store a file into the external storage (Android 4.2.2).
I'm using the correct permission in the manifest.xml:
<manifest ...>
...
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
...
The external sd card is available, I can prove it using other app to read and write files. The path /mnt/extsd/ is valid, look at the picture below. The external sd card is writable because I can copy/paste files into it.
The code:
try {
String path = "/mnt/extsd/file.dat"
File f = new File(path);
f.createNewFile();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
I get the error on f.createNewFile();:
W/System.err(2172): java.io.IOException: open failed: EACCES (Permission denied)
W/System.err(2172): at java.io.File.createNewFile(File.java:948)
W/System.err(2172): at solarapp.activities.settings.application.ActivityBackup$BackupTask.doInBackground(ActivityBackup.java:77)
W/System.err(2172): at solarapp.activities.settings.application.ActivityBackup$BackupTask.doInBackground(ActivityBackup.java:1)
W/System.err(2172): at android.os.AsyncTask$2.call(AsyncTask.java:287)
W/System.err(2172): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
W/System.err(2172): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
W/System.err(2172): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
W/System.err(2172): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
W/System.err(2172): at java.lang.Thread.run(Thread.java:856)
W/System.err(2172): Caused by: libcore.io.ErrnoException: open failed: EACCES (Permission denied)
W/System.err(2172): at libcore.io.Posix.open(Native Method)
W/System.err(2172): at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
W/System.err(2172): at java.io.File.createNewFile(File.java:941)
If I use String path = "/mnt/extsd/file.dat" everything works fine! So, where is the problem?
EDIT
I'm using this solution to get the available storage list:
How can I get the list of mounted external storage of android device
And, as suggested, I post the result of the command adb shell cat /proc/mounts:
rootfs / rootfs rw 0 0
tmpfs /dev tmpfs rw,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
tmpfs /mnt/secure tmpfs rw,relatime,mode=700 0 0
tmpfs /mnt/asec tmpfs rw,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,relatime,mode=755,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
/dev/block/by-name/system /system ext4 ro,relatime,data=ordered 0 0
/dev/block/by-name/cache /cache ext4 rw,nosuid,nodev,noatime,nomblk_io_submit,data=ordered 0 0
/dev/block/by-name/data /data ext4 rw,nosuid,nodev,noatime,nomblk_io_submit,noauto_da_alloc,data=ordered 0 0
/dev/block/vold/93:72 /mnt/sdcard vfat rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro 0 0
/dev/block/vold/93:72 /mnt/secure/asec vfat rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro 0 0
tmpfs /mnt/sdcard/.android_secure tmpfs ro,relatime,size=0k,mode=000 0 0
/dev/block/vold/179:1 /mnt/extsd vfat rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1023,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro 0 0
Response to the command adb shell cat /proc/partitions
major minor #blocks name
93 0 32768 nanda
93 8 16384 nandb
93 16 16384 nandc
93 24 786432 nandd
93 32 1048576 nande
93 40 16384 nandf
93 48 32768 nandg
93 56 524288 nandh
93 64 131072 nandi
93 72 4409344 nandj
179 0 3849216 mmcblk0
179 1 3845120 mmcblk0p1
Response to the command adb shell cat /proc/devices and adb shell ls -l /mnt
Character devices:
1 mem
4 /dev/vc/0
4 tty
5 /dev/tty
5 /dev/console
5 /dev/ptmx
7 vcs
10 misc
13 input
29 fb
81 video4linux
100 telephony
108 ppp
116 alsa
128 ptm
136 pts
150 cedar_dev
166 ttyACM
180 usb
188 ttyUSB
189 usb_device
216 rfcomm
247 lcd
248 capture
249 disp
250 ttyGS
251 ttyS
252 sunxi_pwm
253 bsg
254 rtc
Block devices:
259 blkext
7 loop
8 sd
65 sd
66 sd
67 sd
68 sd
69 sd
70 sd
71 sd
93 nand
128 sd
129 sd
130 sd
131 sd
132 sd
133 sd
134 sd
135 sd
179 mmc
254 device-mapper
/system/bin/sh: cat: and: No such file or directory
/system/bin/sh: cat: adb: No such file or directory
/system/bin/sh: cat: shell: No such file or directory
/system/bin/sh: cat: ls: No such file or directory
/system/bin/sh: cat: -l: No such file or directory
/system/bin/sh: cat: /mnt: Is a directory
Response to the command adb shell ls -l /mnt
drwxr-xr-x root system 2014-04-22 11:56 asec
d---rwxr-x system media_rw 1970-01-01 01:00 extsd
drwxrwx--- media_rw media_rw 2014-04-22 11:56 media
drwxr-xr-x root system 2014-04-22 11:56 obb
d---rwxr-x system sdcard_rw 2014-04-22 12:26 sdcard
drwx------ root root 2014-04-22 11:56 secure
drwx------ shell shell 2014-04-22 11:56 shell
d--------- system system 2014-04-22 11:56 usbhost1
