Android error: Cannot perform this operation because the connection pool has been closed

Question

I have searched StackOverflow and the web for an answer to this question, but I could not find an answer. When I run my application on Gingerbread, it runs fine. But when I run it on 4.2.2, I get this error: java.lang.IllegalStateException Cannot perform this operation because the connection pool has been closed I have a SherlockFragmentActivity which contains two fragments.

Fragment 1:

public final class TodoFragment extends SherlockListFragment {
NotesDbAdapter db;

private static final int DELETE_ID = Menu.FIRST + 1;

public static TodoFragment newInstance(String s) {
    TodoFragment fragment = new TodoFragment();

    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    db = new NotesDbAdapter(getActivity());

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    if (container == null) {
        return null;
    }

    return ll;

}

Fragment 2:

public final class NotesFragment extends SherlockListFragment {
NotesDbAdapter db;
private static final int ACTIVITY_EDIT = 1;

private static final int DELETE_ID = Menu.FIRST + 1;

public static NotesFragment newInstance(String content) {
    NotesFragment fragment = new NotesFragment();

    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    db = new NotesDbAdapter(getActivity());

    db.open();
    if (db.fetchAllNotes().getCount() == 0) {
        doWelcomeMessage();
    }
    db.close();

}

private void doWelcomeMessage() {
    // Show welcome dialog
    startActivity(new Intent(getActivity(), NotesWelcome.class));

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    if (container == null) {
        return null;
    }

    db = new NotesDbAdapter(getActivity());

    db.open();
    if (db.fetchAllNotes().getCount() == 0) {
        doWelcomeMessage();
    }
    db.close();


    return ll;

}

SherlockFragmentActivity:

public class NotesFragmentActivity extends SherlockFragmentActivity {

ViewPager mViewPager;
TabsAdapter mTabsAdapter;
TextView tabCenter;
TextView tabText;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mViewPager = new ViewPager(this);
    mViewPager.setId(R.id.pager);

    setContentView(mViewPager);
    ActionBar bar = getSupportActionBar();
    bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    mTabsAdapter = new TabsAdapter(this, mViewPager);

    mTabsAdapter.addTab(bar.newTab().setText("Notes"), NotesFragment.class,
            null);
    mTabsAdapter.addTab(bar.newTab().setText("Todo List"),
            TodoFragment.class, null);

}

public static class TabsAdapter extends FragmentPagerAdapter implements
        ActionBar.TabListener, ViewPager.OnPageChangeListener {
    private final Context mContext;
    private final ActionBar mActionBar;
    private final ViewPager mViewPager;
    private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

    static final class TabInfo {
        private final Class<?> clss;
        private final Bundle args;

        TabInfo(Class<?> _class, Bundle _args) {
            clss = _class;
            args = _args;
        }
    }

    public TabsAdapter(SherlockFragmentActivity activity, ViewPager pager) {
        super(activity.getSupportFragmentManager());
        mContext = activity;
        mActionBar = activity.getSupportActionBar();
        mViewPager = pager;
        mViewPager.setAdapter(this);
        mViewPager.setOnPageChangeListener(this);
    }

    public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
        TabInfo info = new TabInfo(clss, args);
        tab.setTag(info);
        tab.setTabListener(this);
        mTabs.add(info);
        mActionBar.addTab(tab);
        notifyDataSetChanged();
    }

    @Override
    public int getCount() {
        return mTabs.size();
    }

    @Override
    public Fragment getItem(int position) {
        TabInfo info = mTabs.get(position);
        return Fragment.instantiate(mContext, info.clss.getName(),
                info.args);
    }

    public void onPageScrolled(int position, float positionOffset,
            int positionOffsetPixels) {
    }

    public void onPageSelected(int position) {
        mActionBar.setSelectedNavigationItem(position);
    }

    public void onPageScrollStateChanged(int state) {
    }

    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        Object tag = tab.getTag();
        for (int i = 0; i < mTabs.size(); i++) {
            if (mTabs.get(i) == tag) {
                mViewPager.setCurrentItem(i);
            }
        }
    }

    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    }

    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    }
}
}

I've been stuck on this for HOURS (no jokes), and would really appreciate any help. Thanks again.

Post whole stacktrace. This error means application closes db somewhere and another db connection occurs after that but db is closed — kinghomer, Oct 08 '13 at 11:01
you have to remove close operation . try by removing close() . this error is due to closing the db. — Zar E Ahmer, Aug 19 '14 at 08:33

score 9 · Accepted Answer · answered Apr 23 '13 at 17:13

9

SQLiteConnectionPooling was added in after Android 4.1. Whereas in previous versions a cursor object would simply try to reopen a database if a query or other operation was made on a connection that was closed, with Connection Pooling, an exception is thrown. The NotesDBAdapter is probably a throwback which may have broken compatibility with 4.2.2.

answered Apr 23 '13 at 17:13

user2312380

126
1

2

So, how do we solve that? I'm getting this error sometimes in my app. When in some parts of the code I call cursor.moveToFirst(), then I receive the error: Cannot perform this operation because the connection pool has been closed. – Ferran Negre Apr 25 '14 at 12:35
I wrote this topic http://stackoverflow.com/questions/23293572/android-cannot-perform-this-operation-because-the-connection-pool-has-been-clos/23293930?noredirect=1#23293930 . Read the answer and my comment on that answer :) – Ferran Negre May 26 '14 at 13:23

score 2 · Answer 2 · answered Jul 03 '15 at 11:18

I got the same issue, because multiple threads accessed the same SQLiteOpenHelperand therefore opened and closed the connection simultaneously.

I solved it by adding a userCount attribute to the helper. Now the helper only closes the connection, if the userCount is zero, i.e. no other threads are currently using the database.

Android error: Cannot perform this operation because the connection pool has been closed

2 Answers2

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