文件已加密或不是数据库（异常 net.sqlcipher.database.SQLiteException）

Question

我正在尝试使用 sqlcipher lib 从现有数据库中加密我的数据库，但在访问旧数据库（即打开数据库）时会出现此异常：

 02-27 13:12:21.231: E/AndroidRuntime(14687): FATAL EXCEPTION: main
 02-27 13:12:21.231: E/AndroidRuntime(14687): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.sqlcipher/example.SQLDemoActivity}: net.sqlcipher.database.SQLiteException: file is encrypted or is not a database
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2211)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.ActivityThread.access$600(ActivityThread.java:149)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1300)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.os.Handler.dispatchMessage(Handler.java:99)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.os.Looper.loop(Looper.java:153)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.ActivityThread.main(ActivityThread.java:4987)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at java.lang.reflect.Method.invokeNative(Native Method)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at java.lang.reflect.Method.invoke(Method.java:511)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at dalvik.system.NativeStart.main(Native Method)
 02-27 13:12:21.231: E/AndroidRuntime(14687): Caused by: net.sqlcipher.database.SQLiteException: file is encrypted or is not a database
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at net.sqlcipher.database.SQLiteDatabase.native_setLocale(Native Method)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at net.sqlcipher.database.SQLiteDatabase.setLocale(SQLiteDatabase.java:2102)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at net.sqlcipher.database.SQLiteDatabase.<init>(SQLiteDatabase.java:1968)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at net.sqlcipher.database.SQLiteDatabase.openDatabase(SQLiteDatabase.java:901)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at net.sqlcipher.database.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:944)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at net.sqlcipher.database.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:107)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at example.SQLDemoActivity.onCreate(SQLDemoActivity.java:42)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.Activity.performCreate(Activity.java:5020)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
 02-27 13:12:21.231: E/AndroidRuntime(14687):   ... 11 more

因为我的旧数据库没有加密，所以在这种情况下我应该设置什么密码

我尝试过在密码字符串中传递 null 以及 "" 但没有运气

向https://github.com/sqlcipher/android-database-sqlcipher/issues/124报告问题

Answer 1

因为我的旧数据库没有加密，所以在这种情况下我应该设置什么密码

SQLCipher for Android 可以使用"" 作为密码打开未加密的数据库。

我尝试过在密码字符串中传递 null 以及 "" 但没有运气

然后：

• 您的代码中有错误，或者
• 数据库已经用另一个密码加密，或者
• 数据库已损坏。

Answer 2

1. 检查您是否使用了正确的导入： 导入 net.sqlcipher.database.SQLiteDatabase;

2. 像这样在应用启动时加载库：

SQLiteDatabase.loadLibs(this); //this = activity (usually a SplashScreen or MainActivity)
db = DatabaseHandler.getInstance(this); //if it's singleton (and i suggest making it as such)
db.getReadableDatabase(ConstantsHandler.DATABASE_PASSWORD);
db.close();

1. 确保它尚未使用密码加密

2. 检查文件权限：

android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>