我的安卓应用中的SQLite数据库出现了问题。似乎这种情况偶尔发生,我无法再现,但这是Android Market提供的报告。
基本上,我先有一个闪屏活动,它通过检查数据库中是否有所有所需数据来启动。如果没有,它将在异步线程中安装数据并关闭数据库连接。
然后只有主活动才能被启动,同时打开、读写数据库。
下面是从闪屏活动的onCreate方法执行的代码:
dbWord = new WordDBAdapter(this, myUI);
dbWord.open();
if (dbWord.isDataInstalled()) {
dbWord.close();
databaseInstalled = true;
clickToStartView.setText(myUI.PRESS_TO_START);
clickToStartView.startAnimation(myBlinkAnim);
} else {
// If not, try to install in asynchronous thread
progressDialog = new ProgressDialog(this);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressDialog.setMessage(myUI.INSTALLING_DB);
progressDialog.setCancelable(false);
new InstallDBData().execute("");
}
异步线程的代码为:
private class InstallDBData extends AsyncTask<String, Integer, Integer> {
@Override
protected Integer doInBackground(String... arg0) {
progressDialog.setProgress(0);
dbWord.installData(0, getApplicationContext());
progressDialog.setProgress(20);
dbWord.installData(1, getApplicationContext());
progressDialog.setProgress(40);
dbWord.installData(2, getApplicationContext());
progressDialog.setProgress(60);
dbWord.installData(3, getApplicationContext());
progressDialog.setProgress(80);
dbWord.installData(4, getApplicationContext());
progressDialog.setProgress(100);
return 1;
}
protected void onPreExecute() {
progressDialog.show();
}
protected void onPostExecute(Integer x) {
dbWord.close();
progressDialog.hide();
databaseInstalled = true;
clickToStartView.setText(myUI.PRESS_TO_START);
clickToStartView.startAnimation(myBlinkAnim);
}
}
这些是WordDBAdapter类的重要组成部分,该类也被主活动使用:
public class WordDBAdapter {
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
public WordDBAdapter open() throws android.database.SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
...
}
我得到了以下的异常,它们很相似但有不同的信息:
第一种错误信息:
java.lang.RuntimeException: Unable to start activity
ComponentInfo{example.flashcards.medical/com.example.flashcards.common.SplashWindow}:
android.database.sqlite.SQLiteException: database is locked: BEGIN EXCLUSIVE;
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1830)
....
Caused by: android.database.sqlite.SQLiteException: database is locked: BEGIN EXCLUSIVE;
at android.database.sqlite.SQLiteDatabase.native_execSQL(Native Method)
at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1870)
at android.database.sqlite.SQLiteDatabase.beginTransactionWithListener(SQLiteDatabase.java:602)
第二种错误信息:
java.lang.RuntimeException: Unable to start activity
ComponentInfo{example.flashcards.medical/com.example.flashcards.common.SplashWindow}:
android.database.sqlite.SQLiteException: database is locked
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1768)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784)
....
Caused by: android.database.sqlite.SQLiteException: database is locked
at android.database.sqlite.SQLiteDatabase.native_setLocale(Native Method)
at android.database.sqlite.SQLiteDatabase.setLocale(SQLiteDatabase.java:1987)
at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1855)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:820)
at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:854)
我真的不想创建ContentProvider,因为我认为如果有更简单的解决方案,那就过度了。而且只有这个应用程序可以访问数据库。
有没有任何建议可以解决这个问题?