在android中创建目录

在android中，一次可以创建多少个目录有什么限制吗？ 因为我实际上是想把我的数据库保存在子目录中。所以我使用了下面的代码

DATABASE_NAME = Environment.getExternalStorageDirectory() + "/AllDatabases/" + comp
            + "/Balance/" + wy + ".db";

当我首先创建一个名为“AllDatabases”的文件夹，然后在其中创建一个子文件夹，并使用变量“comp”（比如“lol”）的某个特定值时，代码工作得非常好

然后，它成功地在其中创建了数据库。但是，当我再次删除创建的文件夹时&直接尝试使用上面的语句构建它，其中我为我的数据库名称分配了一些值，它会强制关闭我的应用程序。这是LogCat显示的

01-21 18:03:30.194: E/Database(19098): sqlite3_open_v2("/mnt/sdcard/lol/MyLedgers/2012-2013.db", &handle, 6, NULL) failed
01-21 18:03:30.254: E/SQLiteOpenHelper(19098): Couldn't open /mnt/sdcard/lol/MyLedgers/2012-2013.db for writing (will try read-only):
01-21 18:03:30.254: E/SQLiteOpenHelper(19098): android.database.sqlite.SQLiteException: unable to open database file
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.dbopen(Native Method)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1921)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:883)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:960)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:953)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:548)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:203)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:98)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:158)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.balance.start.LedgerInfoDB.opentoread(LedgerInfoDB.java:78)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.balance.start.MainView.onCreate(MainView.java:101)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2633)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2685)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.access$2300(ActivityThread.java:126)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2038)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.os.Handler.dispatchMessage(Handler.java:99)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.os.Looper.loop(Looper.java:123)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.main(ActivityThread.java:4633)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at java.lang.reflect.Method.invokeNative(Native Method)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at java.lang.reflect.Method.invoke(Method.java:521)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at dalvik.system.NativeStart.main(Native Method)
01-21 18:03:30.254: E/Database(19098): sqlite3_open_v2("/mnt/sdcard/chomu/MyLedgers/2012-2013.db", &handle, 1, NULL) failed
01-21 18:03:30.264: W/dalvikvm(19098): threadid=1: thread exiting with uncaught exception (group=0x400207d8)
01-21 18:03:30.264: E/AndroidRuntime(19098): FATAL EXCEPTION: main
01-21 18:03:30.264: E/AndroidRuntime(19098): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.balance.start/com.balance.start.MainView}: android.database.sqlite.SQLiteException: unable to open database file
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2669)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2685)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.access$2300(ActivityThread.java:126)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2038)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.os.Looper.loop(Looper.java:123)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.main(ActivityThread.java:4633)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at java.lang.reflect.Method.invokeNative(Native Method)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at java.lang.reflect.Method.invoke(Method.java:521)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at dalvik.system.NativeStart.main(Native Method)
01-21 18:03:30.264: E/AndroidRuntime(19098): Caused by: android.database.sqlite.SQLiteException: unable to open database file
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteDatabase.dbopen(Native Method)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1921)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:883)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:168)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.balance.start.LedgerInfoDB.opentoread(LedgerInfoDB.java:78)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.balance.start.MainView.onCreate(MainView.java:101)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2633)
01-21 18:03:30.264: E/AndroidRuntime(19098):    ... 11 more

01-21 18:03:30.194:E/数据库（19098）：sqlite3_open_v2（“/mnt/sdcard/lol/MyLedgers/2012-2013.db”，&handle，6，NULL）失败
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：无法打开/mnt/sdcard/lol/MyLedgers/2012-2013.db进行写入（将尝试只读）：
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：android.database.sqlite.SQLiteException:无法打开数据库文件
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：在android.database.sqlite.SQLiteDatabase.dbopen（本机方法）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.database.sqlite.SQLiteDatabase.（SQLiteDatabase.java:1921）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.database.sqlite.SQLiteDatabase.openDatabase（SQLiteDatabase.java:883）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.database.sqlite.SQLiteDatabase.openOrCreateDatabase（SQLiteDatabase.java:960）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.database.sqlite.SQLiteDatabase.openOrCreateDatabase（SQLiteDatabase.java:953）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.app.ContextImpl.openOrCreateDatabase（ContextImpl.java:548）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.content.ContextWrapper.openOrCreateDatabase（ContextWrapper.java:203）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.database.sqlite.SQLiteOpenHelper.getwriteabledatabase（SQLiteOpenHelper.java:98）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.database.sqlite.SQLiteOpenHelper.getReadableDatabase（SQLiteOpenHelper.java:158）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于com.balance.start.LedgerInfoDB.opentoread（LedgerInfoDB.java:78）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于com.balance.start.MainView.onCreate（MainView.java:101）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1047）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2633）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2685）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：在android.app.ActivityThread.access$2300（ActivityThread.java:126）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.app.ActivityThread$H.handleMessage（ActivityThread.java:2038）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.os.Handler.dispatchMessage（Handler.java:99）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.os.Looper.loop（Looper.java:123）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于android.app.ActivityThread.main（ActivityThread.java:4633）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于java.lang.reflect.Method.invokenactive（本机方法）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于java.lang.reflect.Method.invoke（Method.java:521）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run（ZygoteInit.java:858）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：位于com.android.internal.os.ZygoteInit.main（ZygoteInit.java:616）
01-21 18:03:30.254:E/SQLiteOpenHelper（19098）：在dalvik.system.NativeStart.main（本机方法）
01-21 18:03:30.254:E/数据库（19098）：sqlite3_open_v2（“/mnt/sdcard/chomu/MyLedgers/2012-2013.db”，&handle，1，NULL）失败
01-21 18:03:30.264:W/dalvikvm（19098）：threadid=1：线程以未捕获异常退出（组=0x400207d8）
01-21 18:03:30.264:E/AndroidRuntime（19098）：致命异常：主
01-21 18:03:30.264:E/AndroidRuntime（19098）：java.lang.RuntimeException:无法启动活动组件信息{com.balance.start/com.balance.start.MainView}:android.database.sqlite.SQLiteException:无法打开数据库文件
01-21 18:03:30.264:E/AndroidRuntime（19098）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2669）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2685）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在android.app.ActivityThread.access$2300（ActivityThread.java:126）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在android.app.ActivityThread$H.handleMessage（ActivityThread.java:2038）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在android.os.Handler.dispatchMessage（Handler.java:99）上
01-21 18:03:30.264:E/AndroidRuntime（19098）：在android.os.Looper.loop（Looper.java:123）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在android.app.ActivityThread.main（ActivityThread.java:4633）
01-21 18:03:30.264:E/AndroidRuntime（19098）：位于java.lang.reflect.Method.Invokenactive（本机方法）
01-21 18:03:30.264:E/AndroidRuntime（19098）：位于java.lang.reflect.Method.invoke（Method.java:521）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run（ZygoteInit.java:858）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:616）
01-21 18:03:30.264:E/AndroidRuntime（19098）：在dalvik.system.NativeStart.main（本机方法）
01-21 18:03:30.264:E/AndroidRuntime（19098）：原因：android.database.sqlite.sqlite异常：无法打开数据库文件
01-21 18:03:30.264:E/AndroidRuntime（19098）：位于android.database.sqlite.SQLiteDatabase.dbopen（本机M
01-21 18:03:30.194: E/Database(19098): sqlite3_open_v2("/mnt/sdcard/lol/MyLedgers/2012-2013.db", &handle, 6, NULL) failed
01-21 18:03:30.254: E/SQLiteOpenHelper(19098): Couldn't open /mnt/sdcard/lol/MyLedgers/2012-2013.db for writing (will try read-only):
01-21 18:03:30.254: E/SQLiteOpenHelper(19098): android.database.sqlite.SQLiteException: unable to open database file
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.dbopen(Native Method)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1921)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:883)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:960)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:953)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:548)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:203)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:98)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:158)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.balance.start.LedgerInfoDB.opentoread(LedgerInfoDB.java:78)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.balance.start.MainView.onCreate(MainView.java:101)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2633)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2685)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.access$2300(ActivityThread.java:126)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2038)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.os.Handler.dispatchMessage(Handler.java:99)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.os.Looper.loop(Looper.java:123)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at android.app.ActivityThread.main(ActivityThread.java:4633)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at java.lang.reflect.Method.invokeNative(Native Method)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at java.lang.reflect.Method.invoke(Method.java:521)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
01-21 18:03:30.254: E/SQLiteOpenHelper(19098):  at dalvik.system.NativeStart.main(Native Method)
01-21 18:03:30.254: E/Database(19098): sqlite3_open_v2("/mnt/sdcard/chomu/MyLedgers/2012-2013.db", &handle, 1, NULL) failed
01-21 18:03:30.264: W/dalvikvm(19098): threadid=1: thread exiting with uncaught exception (group=0x400207d8)
01-21 18:03:30.264: E/AndroidRuntime(19098): FATAL EXCEPTION: main
01-21 18:03:30.264: E/AndroidRuntime(19098): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.balance.start/com.balance.start.MainView}: android.database.sqlite.SQLiteException: unable to open database file
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2669)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2685)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.access$2300(ActivityThread.java:126)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2038)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.os.Looper.loop(Looper.java:123)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.main(ActivityThread.java:4633)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at java.lang.reflect.Method.invokeNative(Native Method)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at java.lang.reflect.Method.invoke(Method.java:521)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at dalvik.system.NativeStart.main(Native Method)
01-21 18:03:30.264: E/AndroidRuntime(19098): Caused by: android.database.sqlite.SQLiteException: unable to open database file
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteDatabase.dbopen(Native Method)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1921)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:883)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:168)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.balance.start.LedgerInfoDB.opentoread(LedgerInfoDB.java:78)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at com.balance.start.MainView.onCreate(MainView.java:101)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-21 18:03:30.264: E/AndroidRuntime(19098):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2633)
01-21 18:03:30.264: E/AndroidRuntime(19098):    ... 11 more

File cnxDir = Environment.getExternalStorageDirectory();

    for (String folder : folders) {

        cnxDir = new File(cnxDir.toString() + File.separator + folder);
        if (!cnxDir.exists()) {
            cnxDir.mkdir();

        }

    }