我从异常捕获中收到ESDIR (is a directory)错误。我知道这是因为我使用过的路径出了问题，似乎我引用的是文件夹而不是文件（可能？），但我不确定如何纠正它。
我已检查.mkdirs是否正常工作 - 我可以看到文件已创建。
编辑：有建议。
private void exportDB(){
try {
String DB =getDatabasePath(DBHandler.DATABASE_NAME).toString();
Toast.makeText(getApplicationContext(), "Path is: " +DB, Toast.LENGTH_LONG).show();
String sd = Environment.getExternalStorageDirectory().toString();
Toast.makeText(getApplicationContext(), "Path is: " +sd, Toast.LENGTH_LONG).show();
String backupDBPath = sd + "/com.AH.memorisethai/Backup/database.db";
File currentDB =(getDatabasePath(DBHandler.DATABASE_NAME));
File backupDB = new File(backupDBPath);
backupDB.mkdirs();
Toast.makeText(getApplicationContext(), "Path is: "+backupDBPath, Toast.LENGTH_LONG).show();
FileInputStream inStream = new FileInputStream(currentDB);
FileOutputStream outStream = new FileOutputStream(backupDBPath);
FileChannel inChannel = inStream.getChannel();
FileChannel outChannel = outStream.getChannel();
inChannel.transferTo(0, inChannel.size(), outChannel);
inStream.close();
outStream.close();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG).show();
}
}
错误日志：
02-19 09:45:59.820: W/myApp(22243): Start Copy
02-19 09:45:59.825: W/System.err(22243): java.io.FileNotFoundException: /storage/emulated/0/com.AH.memorisethai/Backup/database.db: open failed: EISDIR (Is a directory)
02-19 09:45:59.825: W/System.err(22243): at libcore.io.IoBridge.open(IoBridge.java:409)
02-19 09:45:59.825: W/System.err(22243): at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
02-19 09:45:59.825: W/System.err(22243): at java.io.FileOutputStream.<init>(FileOutputStream.java:128)
02-19 09:45:59.830: W/System.err(22243): at java.io.FileOutputStream.<init>(FileOutputStream.java:117)
02-19 09:45:59.830: W/System.err(22243): at com.AH.memorisethai.MainMenu.exportDB(MainMenu.java:44)
02-19 09:45:59.830: W/System.err(22243): at com.AH.memorisethai.MainMenu.onCreate(MainMenu.java:23)
02-19 09:45:59.830: W/System.err(22243): at android.app.Activity.performCreate(Activity.java:5372)
02-19 09:45:59.830: W/System.err(22243): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
02-19 09:45:59.830: W/System.err(22243): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2257)
02-19 09:45:59.830: W/System.err(22243): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349)
02-19 09:45:59.830: W/System.err(22243): at android.app.ActivityThread.access$700(ActivityThread.java:159)
02-19 09:45:59.830: W/System.err(22243): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
02-19 09:45:59.830: W/System.err(22243): at android.os.Handler.dispatchMessage(Handler.java:99)
02-19 09:45:59.830: W/System.err(22243): at android.os.Looper.loop(Looper.java:176)
02-19 09:45:59.830: W/System.err(22243): at android.app.ActivityThread.main(ActivityThread.java:5419)
02-19 09:45:59.830: W/System.err(22243): at java.lang.reflect.Method.invokeNative(Native Method)
02-19 09:45:59.830: W/System.err(22243): at java.lang.reflect.Method.invoke(Method.java:525)
02-19 09:45:59.830: W/System.err(22243): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
02-19 09:45:59.830: W/System.err(22243): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
02-19 09:45:59.830: W/System.err(22243): at dalvik.system.NativeStart.main(Native Method)
02-19 09:45:59.830: W/System.err(22243): Caused by: libcore.io.ErrnoException: open failed: EISDIR (Is a directory)
02-19 09:45:59.830: W/System.err(22243): at libcore.io.Posix.open(Native Method)
02-19 09:45:59.830: W/System.err(22243): at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
02-19 09:45:59.830: W/System.err(22243): at libcore.io.IoBridge.open(IoBridge.java:393)
02-19 09:45:59.835: W/System.err(22243): ... 19 more
根据收到的反馈，我更改了代码，因此目录路径和文件路径有单独的File变量。我还添加了支票以确保文件/文件夹存在：
private void exportDB(){
try {
File DB =getDatabasePath(DBHandler.DATABASE_NAME);
if (DB.isFile()){
Toast.makeText(getApplicationContext(), "File isFile: " +DB, Toast.LENGTH_LONG).show();
Log.w("myApp", "File:"+DB);
} else if (DB.isDirectory()){
Toast.makeText(getApplicationContext(), "Folder isDirectory: " +DB, Toast.LENGTH_LONG).show();
Log.w("myApp", "Folder:"+DB);
}
File sd = Environment.getExternalStorageDirectory();
Toast.makeText(getApplicationContext(), "Path is: " +sd, Toast.LENGTH_LONG).show();
File backupDBFolder = new File(sd, "/com.AH.memorisethai/Backup/");
File backupDBFile = new File(sd, "/com.AH.memorisethai/Backup/database.db");
backupDBFolder.mkdirs();
if (backupDBFolder.isDirectory()){
Log.w("myApp","External folder isDirectory: "+backupDBFolder);
} else{
Log.w("myApp","Nothing found");
}
Log.w("myApp", "Start Copy");
FileInputStream inStream = new FileInputStream(DB);
FileOutputStream outStream = new FileOutputStream(backupDBFile);
FileChannel inChannel = inStream.getChannel();
FileChannel outChannel = outStream.getChannel();
inChannel.transferTo(0, inChannel.size(), outChannel);
inStream.close();
outStream.close();
Log.w("myApp", "End Copy");
} catch (Exception e) {
e.printStackTrace();
//Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG).show();
}
}
然后我从Logcat获得以下内容：
02-19 12:00:51.468: W/myApp(9243): File:/data/data/com.AH.memorisethai/databases/wordsmanager
02-19 12:00:51.483: W/myApp(9243): External folder isDirectory: /storage/emulated/0/com.AH.memorisethai/Backup
02-19 12:00:51.483: W/myApp(9243): Start Copy
02-19 12:00:51.483: W/System.err(9243): java.io.FileNotFoundException: /storage/emulated/0/com.AH.memorisethai/Backup/database.db: open failed: EISDIR (Is a directory)
02-19 12:00:51.488: W/System.err(9243): at libcore.io.IoBridge.open(IoBridge.java:409)
02-19 12:00:51.488: W/System.err(9243): at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
02-19 12:00:51.488: W/System.err(9243): at java.io.FileOutputStream.<init>(FileOutputStream.java:73)
02-19 12:00:51.488: W/System.err(9243): at com.AH.memorisethai.MainMenu.exportDB(MainMenu.java:53)
02-19 12:00:51.488: W/System.err(9243): at com.AH.memorisethai.MainMenu.onCreate(MainMenu.java:23)
02-19 12:00:51.488: W/System.err(9243): at android.app.Activity.performCreate(Activity.java:5372)
02-19 12:00:51.488: W/System.err(9243): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
02-19 12:00:51.488: W/System.err(9243): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2257)
02-19 12:00:51.488: W/System.err(9243): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349)
02-19 12:00:51.488: W/System.err(9243): at android.app.ActivityThread.access$700(ActivityThread.java:159)
02-19 12:00:51.488: W/System.err(9243): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
02-19 12:00:51.488: W/System.err(9243): at android.os.Handler.dispatchMessage(Handler.java:99)
02-19 12:00:51.488: W/System.err(9243): at android.os.Looper.loop(Looper.java:176)
02-19 12:00:51.488: W/System.err(9243): at android.app.ActivityThread.main(ActivityThread.java:5419)
02-19 12:00:51.488: W/System.err(9243): at java.lang.reflect.Method.invokeNative(Native Method)
02-19 12:00:51.488: W/System.err(9243): at java.lang.reflect.Method.invoke(Method.java:525)
02-19 12:00:51.488: W/System.err(9243): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
02-19 12:00:51.488: W/System.err(9243): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
02-19 12:00:51.488: W/System.err(9243): at dalvik.system.NativeStart.main(Native Method)
02-19 12:00:51.488: W/System.err(9243): Caused by: libcore.io.ErrnoException: open failed: EISDIR (Is a directory)
02-19 12:00:51.493: W/System.err(9243): at libcore.io.Posix.open(Native Method)
02-19 12:00:51.493: W/System.err(9243): at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
02-19 12:00:51.493: W/System.err(9243): at libcore.io.IoBridge.open(IoBridge.java:393)
02-19 12:00:51.493: W/System.err(9243): ... 18 more
所以尽管对文件路径使用单独的变量，它仍然认为它是一个目录？
答案 0 :(得分：3)
<强>更新
因此，您的LogCat错误报告指出以下路径不是文件而是目录。
/storage/emulated/0/com.AH.memorisethai/Backup/database.db
这就是为什么当您在以下行中传递此路径时，它会抛出java.io.FileNotFoundException错误。
FileOutputStream outStream = new FileOutputStream(backupDBPath);
我想，现在你可以解决问题所在。因此，您必须确保在将路径传递给FileOutputStream()构造函数时，其文件不是目录。
解决方案可以是......假设您尝试在Database文件中备份Text.txt，然后您的更正后的代码应如下所示....
String backupDBPath = sd + "/com.AH.memorisethai/Backup/database.db";
File backupDirectory = new File(backupDBPath);
backupDirectory.mkdirs();
String backupFilePath = backupDBPath + "/" + "Text.txt";
File backupFile = new File(backupFilePath);
FileOutputStream outStream = new FileOutputStream(backupFile);
这将解决您的所有问题。
答案 1 :(得分：1)
问题是您必须创建没有文件名的目录，并使用文件名复制文件。
private void exportDB(){
try {
String DB =getDatabasePath(DBHandler.DATABASE_NAME).toString();
Toast.makeText(getApplicationContext(), "Path is: " +DB, Toast.LENGTH_LONG).show();
String sd = Environment.getExternalStorageDirectory().toString();
Toast.makeText(getApplicationContext(), "Path is: " +sd, Toast.LENGTH_LONG).show();
String backupDBPath = sd + "/com.AH.memorisethai/Backup/";
String backupDBFile = sd + "/com.AH.memorisethai/Backup/database.db";
File currentDB =(getDatabasePath(DBHandler.DATABASE_NAME));
File backupDB = new File(backupDBPath);
File backupFile = new File(backupDBFile);
backupDB.mkdirs();
Toast.makeText(getApplicationContext(), "Path is: "+backupDBPath, Toast.LENGTH_LONG).show();
FileInputStream inStream = new FileInputStream(currentDB);
FileOutputStream outStream = new FileOutputStream(backupFile);
FileChannel inChannel = inStream.getChannel();
FileChannel outChannel = outStream.getChannel();
inChannel.transferTo(0, inChannel.size(), outChannel);
inStream.close();
outStream.close();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG).show();
}
}