我有一个SQLiteDatabase数据成员，我在onCreate中初始化并在onPause（），onStop（）和onDestroy（）上调用.close（）。它在onResume（）中重新初始化。它看起来运行得很好但是当我查看调试器时它会看到：
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
我得到此错误的一个地方是离开此活动时：
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
但奇怪的是，这个错误并不是持久性的。
我是否需要做更多事情然后致电.close（）？
答案 0 :(得分：4)
问题是你在onCreate和onResume中创建/打开它，所以你要做两次。同样地，你关闭它两次，所以它可能会崩溃。
一般情况下 - 为什么不使用SQLiteOpenHelper？这将使管理数据库变得更加容易。
答案 1 :(得分：2)
为了支持EboMike的观点，请查看Android Activity lifecycle，您的代码问题就很明显了。