java - Android 认为我没有关闭我的数据库!为什么？

Question

我有一个 SQLiteDatabase 数据成员，我在 onCreate 中初始化它并在 onPause()、onStop() 和 onDestroy() 中调用 .close()。它在 onResume() 中重新初始化。它似乎运行得很好但是当我查看调试器时它看到了这个:

08-24 20:23:50.014: ERROR/Database(6767): Leak found
08-24 20:23:50.014: ERROR/Database(6767): java.lang.IllegalStateException: /data/data/com.hh.Timepunch/databases/times_database.db SQLiteDatabase created and never closed
08-24 20:23:50.014: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1695)
08-24 20:23:50.014: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:739)
08-24 20:23:50.014: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:761)
08-24 20:23:50.014: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:754)
08-24 20:23:50.014: ERROR/Database(6767):     at android.app.ApplicationContext.openOrCreateDatabase(ApplicationContext.java:476)
08-24 20:23:50.014: ERROR/Database(6767):     at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:193)
08-24 20:23:50.014: ERROR/Database(6767):     at com.hh.Timepunch.TimeSheetActivity.onCreate(TimeSheetActivity.java:72)
08-24 20:23:50.014: ERROR/Database(6767):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-24 20:23:50.014: ERROR/Database(6767):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
08-24 20:23:50.014: ERROR/Database(6767):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
08-24 20:23:50.014: ERROR/Database(6767):     at android.app.ActivityThread.access$2200(ActivityThread.java:119)
08-24 20:23:50.014: ERROR/Database(6767):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
08-24 20:23:50.014: ERROR/Database(6767):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-24 20:23:50.014: ERROR/Database(6767):     at android.os.Looper.loop(Looper.java:123)
08-24 20:23:50.014: ERROR/Database(6767):     at android.app.ActivityThread.main(ActivityThread.java:4363)
08-24 20:23:50.014: ERROR/Database(6767):     at java.lang.reflect.Method.invokeNative(Native Method)
08-24 20:23:50.014: ERROR/Database(6767):     at java.lang.reflect.Method.invoke(Method.java:521)
08-24 20:23:50.014: ERROR/Database(6767):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-24 20:23:50.014: ERROR/Database(6767):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-24 20:23:50.014: ERROR/Database(6767):     at dalvik.system.NativeStart.main(Native Method)
08-24 20:23:50.054: ERROR/Database(6767): Leak found
08-24 20:23:50.054: ERROR/Database(6767): java.lang.IllegalStateException: /data/data/com.hh.Timepunch/databases/times_database.db SQLiteDatabase created and never closed
08-24 20:23:50.054: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1695)
08-24 20:23:50.054: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:739)
08-24 20:23:50.054: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:761)
08-24 20:23:50.054: ERROR/Database(6767):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:754)
08-24 20:23:50.054: ERROR/Database(6767):     at android.app.ApplicationContext.openOrCreateDatabase(ApplicationContext.java:476)
08-24 20:23:50.054: ERROR/Database(6767):     at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:193)
08-24 20:23:50.054: ERROR/Database(6767):     at com.hh.Timepunch.TimepunchActivity.onCreate(TimepunchActivity.java:60)
08-24 20:23:50.054: ERROR/Database(6767):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-24 20:23:50.054: ERROR/Database(6767):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
08-24 20:23:50.054: ERROR/Database(6767):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
08-24 20:23:50.054: ERROR/Database(6767):     at android.app.ActivityThread.access$2200(ActivityThread.java:119)
08-24 20:23:50.054: ERROR/Database(6767):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
08-24 20:23:50.054: ERROR/Database(6767):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-24 20:23:50.054: ERROR/Database(6767):     at android.os.Looper.loop(Looper.java:123)
08-24 20:23:50.054: ERROR/Database(6767):     at android.app.ActivityThread.main(ActivityThread.java:4363)
08-24 20:23:50.054: ERROR/Database(6767):     at java.lang.reflect.Method.invokeNative(Native Method)
08-24 20:23:50.054: ERROR/Database(6767):     at java.lang.reflect.Method.invoke(Method.java:521)
08-24 20:23:50.054: ERROR/Database(6767):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-24 20:23:50.054: ERROR/Database(6767):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-24 20:23:50.054: ERROR/Database(6767):     at dalvik.system.NativeStart.main(Native Method)
08-24 20:23:50.199: ERROR/libs3c2drender(1912): int S3c2DRender::DoG2D(unsigned int, s3c_img*, s3c_rect*, unsigned int, s3c_img*, s3c_rect*, int, int)::S3C_G2D_ROTATOR_18176 fail

我遇到此错误的地方之一是在离开此 Activity 时:

public class TimepunchActivity extends Activity {

        Calendar timeNow = Calendar.getInstance();
        SQLiteDatabase timesDatabase;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.timepunch);

            //Create/open and configure database (if necessary)
            timesDatabase = openOrCreateDatabase(
                    "times_database.db",
                    SQLiteDatabase.CREATE_IF_NECESSARY,
                    null);
            timesDatabase.setLocale(Locale.getDefault());
            timesDatabase.setLockingEnabled(false);
            timesDatabase.setVersion(3);

            //lenient is set to true so incrementing minute 59 auto increments hour, etc
            timeNow.setLenient(true);

            //Create table (if necessary)
            final String dbCommand = "CREATE TABLE IF NOT EXISTS Timepunches (punch INTEGER PRIMARY KEY);";
            timesDatabase.execSQL(dbCommand);

            updateLastInPunch();

            Button punchButton = (Button)findViewById(R.id.punch_button);
            punchButton.setHapticFeedbackEnabled(true);
            punchButton.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    //Insert data
                    ContentValues punchValue = new ContentValues();
                    punchValue.put("punch", timeNow.getTimeInMillis());
                    long newPunchID = timesDatabase.insert("Timepunches", null, punchValue);
                    punchValue.clear();

                    //if punch already exists
                    if (newPunchID < 0) {
                        AlertDialog.Builder builder = new AlertDialog.Builder(TimepunchActivity.this);
                        builder.setTitle("Whoops")
                            .setMessage("I've already recorded a punch for this time and day.")
                            .setCancelable(true)
                            .setNeutralButton("Oh", new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    dialog.cancel();
                                }
                            })
                            .show();
                    }
                    else {
                    }
                } //end setOnClick()
            }); //end click listener for punchButton
        } //end onCreate()



        @Override
        public void onResume() {
            super.onResume();
            checkFirstTimer();

            //Open and configure database
            timesDatabase = openOrCreateDatabase(
                    "times_database.db",
                    SQLiteDatabase.CREATE_IF_NECESSARY,
                    null);
            timesDatabase.setLocale(Locale.getDefault());
            timesDatabase.setLockingEnabled(false);
            timesDatabase.setVersion(3);


            //Update date object for current time
            timeNow.setTimeInMillis(System.currentTimeMillis());
            timeNow.set(Calendar.SECOND, 0);
            timeNow.set(Calendar.MILLISECOND, 0);
            updateClock((TextView)findViewById(R.id.current_time_textbox), timeNow);

            updateLastInPunch();
        } //end onResume()


        @Override
        public void onPause() {
            super.onPause();
            timesDatabase.close();
        } //end onResume()

        @Override
        public void onStop() {
            super.onStop();
            timesDatabase.close();
        } //end onResume()

        @Override
        public void onDestroy() {
            super.onDestroy();
            timesDatabase.close();
        } //end onResume()



        //Shows last in-punch that has no out-punch
        // if there is none it hides the section
        public void updateLastInPunch() {
            Cursor punchCursor = timesDatabase.query("Timepunches", null, null, null, null, null, "punch ASC;");

            TextView inPunchLabel = (TextView)findViewById(R.id.in_punch_label_textview);
            TextView inPunchTV = (TextView)findViewById(R.id.in_punch_time_textview);

            //odd count means there is a missing punch (assumed to be latest in punch)
            // therefore show last in punch
            if ((punchCursor.getCount()%2) != 0) {
                punchCursor.moveToLast();
                Calendar lastIn = Calendar.getInstance();
                lastIn.setTimeInMillis(punchCursor.getLong(0));

                updateClock((TextView)findViewById(R.id.in_punch_time_textview), lastIn);

                inPunchLabel.setVisibility(View.VISIBLE);
                inPunchLabel.setAnimation(fadeInAnimation);
                inPunchLabel.startAnimation(fadeInAnimation);

                inPunchTV.setVisibility(View.VISIBLE);
                inPunchTV.setAnimation(fadeInAnimation);
                inPunchTV.startAnimation(fadeInAnimation);
            }
            else {
                //only fade when "turning off" last punch display
                // (don't fade away when returning to screen)
                if (inPunchLabel.getVisibility() == View.VISIBLE) {
                    inPunchLabel.setAnimation(fadeOutAnimation);
                    inPunchLabel.startAnimation(fadeOutAnimation);
                    inPunchLabel.setVisibility(View.INVISIBLE);

                    inPunchTV.setAnimation(fadeOutAnimation);
                    inPunchTV.startAnimation(fadeOutAnimation);
                    inPunchTV.setVisibility(View.INVISIBLE);
                }
            }
            punchCursor.close();
        } //end getLastInPunch()
    } //end TimepunchActivity

不过，奇怪的是，这个错误并不是持久存在的。

我是否需要做更多然后调用 .close()？

Answer 1

问题是您在 onCreate 和 onResume 中创建/打开它，所以您要执行两次。同样，您将其关闭两次，因此它可能会崩溃。

一般来说——你为什么不使用SQLiteOpenHelper？这将使您的数据库管理变得更加容易。