问题
I am attempting to write a file to external storage in android. I keep getting the error, "java.io.FileNotFoundException: /mnt/sdcard/Survey.txt (Is a directory)." The method that contains the code for this is as follows:
public String sendFile(System system) throws FileNotFoundException {
File writeable = new File(Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/Survey.txt");
try {
writeable.createNewFile();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
Log.w("Before FO", "***");
if (!Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
Toast.makeText(context, "External SD card not mounted",
Toast.LENGTH_LONG).show();
} else {
FileOutputStream f = new FileOutputStream(writeable);
Log.w("before write", "0");
f.write("HELLOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO".getBytes());
Log.w("before write", "1");
f.close();
}
} catch (Exception e) {
Log.w("Write sd", e.toString());
}
return writeable.getAbsolutePath();
}
I believe the program is crashing on the FileOutputStream deceleration, because Log.w("Before FO", "*"); executes. I have been searching for an answer to this problem for several day, so any help will be greatly appreciated. Thanks!
01-19 14:07:33.839: W/Before FO(641): ***
01-19 14:07:33.857: W/Write sd(641): java.io.FileNotFoundException: /mnt/sdcard/Survey.txt (Is a directory)
01-19 14:07:33.857: W/Write sd(641): at org.apache.harmony.luni.platform.OSFileSystem.open(Native Method)
01-19 14:07:33.857: W/Write sd(641): at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:239)
01-19 14:07:33.857: W/Write sd(641): at java.io.FileOutputStream.<init>(FileOutputStream.java:101)
01-19 14:07:33.857: W/Write sd(641): at java.io.FileOutputStream.<init>(FileOutputStream.java:77)
01-19 14:07:33.857: W/Write sd(641): at premise.survey.IOInterface.sendFile(IOInterface.java:315)
01-19 14:07:33.857: W/Write sd(641): at premise.survey.PremiseSurveyActivity.onClick(PremiseSurveyActivity.java:1119)
01-19 14:07:33.857: W/Write sd(641): at android.view.View.performClick(View.java:3110)
01-19 14:07:33.857: W/Write sd(641): at android.view.View$PerformClick.run(View.java:11934)
01-19 14:07:33.857: W/Write sd(641): at android.os.Handler.handleCallback(Handler.java:587)
01-19 14:07:33.857: W/Write sd(641): at android.os.Handler.dispatchMessage(Handler.java:92)
01-19 14:07:33.857: W/Write sd(641): at android.os.Looper.loop(Looper.java:132)
01-19 14:07:33.857: W/Write sd(641): at android.app.ActivityThread.main(ActivityThread.java:4123)
01-19 14:07:33.857: W/Write sd(641): at java.lang.reflect.Method.invokeNative(Native Method)
01-19 14:07:33.857: W/Write sd(641): at java.lang.reflect.Method.invoke(Method.java:491)
01-19 14:07:33.857: W/Write sd(641): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
01-19 14:07:33.857: W/Write sd(641): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
01-19 14:07:33.857: W/Write sd(641): at dalvik.system.NativeStart.main(Native Method)
01-19 14:07:33.857: I/ActivityManager(73): Starting: Intent { act=android.intent.action.CHOOSER cmp=android/com.android.internal.app.ChooserActivity (has extras) } from pid 641
01-19 14:07:33.857: W/WindowManager(73): Failure taking screenshot for (230x341) to layer 21020
01-19 14:07:34.027: I/ActivityManager(73): Starting: Intent { act=android.intent.action.SEND typ=plain/text flg=0x3000000 cmp=com.android.email/.activity.MessageCompose (has extras) } from pid 641
01-19 14:07:35.269: I/ActivityManager(73): Displayed com.android.email/.activity.MessageCompose: +1s197ms (total +1s391ms)
01-19 14:07:40.647: D/dalvikvm(252): GC_EXPLICIT freed 164K, 5% free 7462K/7815K, paused 4ms+3ms
01-19 14:07:45.727: D/dalvikvm(269): GC_EXPLICIT freed 8K, 8% free 6305K/6791K, paused 13ms+5ms
01-19 14:12:04.720: D/SntpClient(73): request time failed: java.net.SocketException: Address family not supported by protocol
01-19 14:12:15.947: I/Email(293): ReconcilePopImapAccountsSync: start
01-19 14:12:15.977: I/Email(293): ReconcilePopImapAccountsSync: done
01-19 14:12:16.137: D/dalvikvm(293): GC_CONCURRENT freed 236K, 8% free 7787K/8391K, paused 4ms+7ms
01-19 14:12:16.137: W/CursorWrapperInner(293): Cursor finalized without prior close()
Line 315 in IOInterface.java is FileOutputStream f = new FileOutputStream(writeable);
回答1:
After doing a few more hours of research on this topic, I found a place were another person had posted a different way of doing this, and it is as follows:
String fileName = surveyName + ".csv";
String headings = "Hello, world!";
File path = Environment.getExternalStorageDirectory();
File file = new File(path, fileName);
path.mkdirs();
OutputStream os = new FileOutputStream(file);
os.write(headings.getBytes());
回答2:
You may find that the file you are trying to write to is actually a directory. Find the file/directory and delete it.
I ran into this when I was first working with files. I called File.mkdirs() expecting it to just create the directories, but it created a directory with the filename that I specified.
When I create files I use two File objects. The first references just the path, and I call mkdirs(). The second then references the file.
//create path
File directoryFile = new File(Environment.getExternalStorageDirectory(), "");
directoryFile.mkdirs();
//create file
File outFile = new File(Environment.getExternalStorageDirectory(), filename);
来源：https://stackoverflow.com/questions/8931671/writing-to-external-storage-filenotfoundexception