Android 错误 - close() 从未在数据库上显式调用答案

【问题标题】：Android error - close() was never explicitly called on databaseAndroid 错误 - close() 从未在数据库上显式调用
【发布时间】：2011-05-26 18:42:37
【问题描述】：

我应该在代码的哪里调用 close()？

LogCat 返回此错误：

close() 从未在数据库上显式调用 android.database.sqlite.DatabaseObjectNotClosedException：应用程序没有关闭此处打开的游标或数据库对象

错误是这样的：

> 12-16 17:24:50.886: ERROR/Database(10982): close() was never explicitly called on database '/data/data/com.psyhclo/databases/calls.db' 
12-16 17:24:50.886: ERROR/Database(10982): android.database.sqlite.DatabaseObjectNotClosedException: Application did not close the cursor or database object that was opened here
12-16 17:24:50.886: ERROR/Database(10982):     at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1827)
12-16 17:24:50.886: ERROR/Database(10982):     at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:820)
12-16 17:24:50.886: ERROR/Database(10982):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:854)
12-16 17:24:50.886: ERROR/Database(10982):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:847)
12-16 17:24:50.886: ERROR/Database(10982):     at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:541)
12-16 17:24:50.886: ERROR/Database(10982):     at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:203)
12-16 17:24:50.886: ERROR/Database(10982):     at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:118)
12-16 17:24:50.886: ERROR/Database(10982):     at com.psyhclo.CallDataHelper.<init>(CallDataHelper.java:27)
12-16 17:24:50.886: ERROR/Database(10982):     at com.psyhclo.RatedCalls.fillList(RatedCalls.java:66)
12-16 17:24:50.886: ERROR/Database(10982):     at com.psyhclo.RatedCalls.access$0(RatedCalls.java:63)
12-16 17:24:50.886: ERROR/Database(10982):     at com.psyhclo.RatedCalls$RatedCallsContentObserver.onChange(RatedCalls.java:58)
12-16 17:24:50.886: ERROR/Database(10982):     at android.database.ContentObserver$NotificationRunnable.run(ContentObserver.java:43)
12-16 17:24:50.886: ERROR/Database(10982):     at android.os.Handler.handleCallback(Handler.java:587)
12-16 17:24:50.886: ERROR/Database(10982):     at android.os.Handler.dispatchMessage(Handler.java:92)
12-16 17:24:50.886: ERROR/Database(10982):     at android.os.Looper.loop(Looper.java:123)
12-16 17:24:50.886: ERROR/Database(10982):     at android.app.ActivityThread.main(ActivityThread.java:3647)
12-16 17:24:50.886: ERROR/Database(10982):     at java.lang.reflect.Method.invokeNative(Native Method)
12-16 17:24:50.886: ERROR/Database(10982):     at java.lang.reflect.Method.invoke(Method.java:507)
12-16 17:24:50.886: ERROR/Database(10982):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
12-16 17:24:50.886: ERROR/Database(10982):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
12-16 17:24:50.886: ERROR/Database(10982):     at dalvik.system.NativeStart.main(Native Method)

这是我的代码。

活动：

public class RatedCalls extends ListActivity {

private static final String LOG_TAG = "RATEDCALLSOBSERVER";
private Handler handler = new Handler();
private SQLiteDatabase db;
private CallDataHelper cdh; 
StringBuilder sb = new StringBuilder();
OpenHelper openHelper = new OpenHelper(RatedCalls.this);

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    registerContentObservers();
    Log.d("FILLLIST", "calling from onCreate()");

}

class RatedCallsContentObserver extends ContentObserver {
    public RatedCallsContentObserver(Handler h) {
        super(h);
    }

    @Override
    public boolean deliverSelfNotifications() {
        return true;

    }

    @Override
    public void onChange(boolean selfChange) {
        Log.d(LOG_TAG, "RatedCallsContentObserver.onChange( " + selfChange
                + ")");
        super.onChange(selfChange);
        fillList();
        onStop();
    }
}

private void fillList() {

    db = openHelper.getWritableDatabase();
    cdh = new CallDataHelper(this);
    String lastDate = cdh.selectDate();

    Cursor cursor = getContentResolver().query(
            android.provider.CallLog.Calls.CONTENT_URI, null,
            android.provider.CallLog.Calls.DATE + " < ?",
            new String[] { lastDate },
            android.provider.CallLog.Calls.DATE + " DESC ");

    Log.d("FILLLIST", "Calling from filllist");

    startManagingCursor(cursor);
    int numberColumnId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.NUMBER);
    int durationId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.DURATION);
    int contactNameId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.CACHED_NAME);        
    int numTypeId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.CACHED_NUMBER_TYPE);

    Date dt = new Date();
    int hours = dt.getHours();
    int minutes = dt.getMinutes();
    int seconds = dt.getSeconds();
    String currTime = hours + ":" + minutes + ":" + seconds;

    SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd-yyyy");
    Date date = new Date();

    ArrayList<String> callList = new ArrayList<String>();
    cursor.moveToFirst();

    String contactNumber = cursor.getString(numberColumnId);
    String contactName = cursor.getString(contactNameId);
    String duration = cursor.getString(durationId);
    // String callDate = DateFormat.getDateInstance().format(dateId);
    String numType = cursor.getString(numTypeId);

    ContentValues values = new ContentValues();

    values.put("contact_id", 1);
    values.put("contact_name", contactName);
    values.put("number_type", numType);
    values.put("contact_number", contactNumber);
    values.put("duration", duration);
    values.put("date", dateFormat.format(date));
    values.put("current_time", currTime);
    values.put("cont", 1);
    getBaseContext().getContentResolver().notifyChange(
            android.provider.CallLog.Calls.CONTENT_URI,
            new RatedCallsContentObserver(handler));
    db.insert(CallDataHelper.TABLE_NAME, null, values);
    Toast.makeText(getBaseContext(), "Inserted!", Toast.LENGTH_LONG);
    callList.add("Contact Number: " + contactNumber + "\nContact Name: "
            + contactName + "\nDuration: " + duration + "\nDate: "
            + dateFormat.format(date));

    setListAdapter(new ArrayAdapter<String>(this, R.layout.listitem,
            callList));
    ListView lv = getListView();
    lv.setTextFilterEnabled(true);

    lv.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

            Toast.makeText(getApplicationContext(),
                    ((TextView) view).getText(), Toast.LENGTH_SHORT).show();

        }
    });
}

public void registerContentObservers() {

    this.getApplicationContext()
            .getContentResolver()
            .registerContentObserver(
                    android.provider.CallLog.Calls.CONTENT_URI, true,
                    new RatedCallsContentObserver(handler));

}

public void unregisterContentObservers() {

    this.getApplicationContext()
            .getContentResolver()
            .unregisterContentObserver(
                    new RatedCallsContentObserver(handler));

}
    }

还有 DatabaseHelper

public class CallDataHelper {

private static final String DATABASE_NAME = "calls.db";
private static final int DATABASE_VERSION = 1;
protected static final String TABLE_NAME = "contact_data";

private Context context;
private SQLiteDatabase db;

public CallDataHelper(Context context) {
    this.context = context;
    OpenHelper openHelper = new OpenHelper(this.context);
    this.db = openHelper.getWritableDatabase();
}

public boolean insert(Integer cId, String cName, String numType,
        String cNum, String dur, String date, String currTime) {
    this.db.execSQL("insert into "
            + TABLE_NAME
            + " (contact_id, contact_name, number_type, contact_number, duration, date, current_time, cont) "
            + " values( " + cId + ", " + cName + ", " + numType + ", "
            + cNum + ", " + dur + ", " + date + ", " + currTime + ", 1)");
    return true;        
}   

public void update(String word) {
    this.db.execSQL("UPDATE words SET cont = cont + 1 WHERE (word= ?)",
            new String[] { word });
}

public void deleteAll() {
    this.db.delete(TABLE_NAME, null, null);
}

public String selectDate() {

    String date = "";
    Cursor cursor = this.db.query(TABLE_NAME, new String[] { "date" },
            "id = ?", new String[] { "max(id)" }, null, null, null);
    if (cursor.moveToFirst()) {
        do {
            date = cursor.getString(0);
        } while (cursor.moveToNext());
    }
    if (cursor != null && !cursor.isClosed()) {
        cursor.close();
        return date;
    } else {
        return "";
    }
}

public List<String> selectAll() {
    List<String> list = new ArrayList<String>();
    Cursor cursor = this.db.query(TABLE_NAME, new String[] { "word" },
            null, null, null, null, "cont desc");
    if (cursor.moveToFirst()) {
        do {
            list.add(cursor.getString(0).toUpperCase());
        } while (cursor.moveToNext());
    }
    if (cursor != null && !cursor.isClosed()) {
        cursor.close();
    }
    return list;
}

public static class OpenHelper extends SQLiteOpenHelper {

    OpenHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE "
                + TABLE_NAME
                + "(id INTEGER PRIMARY KEY AUTOINCREMENT, contact_id INTEGER, contact_name VARCHAR(50), number_type VARCHAR(50), contact_number VARCHAR(50), duration TIME, date DATE, current_time TIME, cont INTEGER)");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.w("RatedCalls Database",
                "Upgrading database, this will drop tables and recreate.");
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }
}
    }

____（已编辑）_______

这就是我现在得到的。当我打一个新电话时，Logcat 会返回这个。

12-16 18:55:27.365: ERROR/AndroidRuntime(767): FATAL EXCEPTION: main
12-16 18:55:27.365: ERROR/AndroidRuntime(767): java.lang.IllegalStateException: database not open
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1230)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1189)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1271)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at com.psyhclo.CallDataHelper.selectDate(CallDataHelper.java:61)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at com.psyhclo.RatedCalls.fillList(RatedCalls.java:98)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at com.psyhclo.RatedCalls.access$0(RatedCalls.java:96)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at com.psyhclo.RatedCalls$RatedCallsContentObserver.onChange(RatedCalls.java:91)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.database.ContentObserver$NotificationRunnable.run(ContentObserver.java:43)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.os.Handler.handleCallback(Handler.java:587)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.os.Handler.dispatchMessage(Handler.java:92)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.os.Looper.loop(Looper.java:123)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at android.app.ActivityThread.main(ActivityThread.java:3647)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at java.lang.reflect.Method.invokeNative(Native Method)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at java.lang.reflect.Method.invoke(Method.java:507)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
12-16 18:55:27.365: ERROR/AndroidRuntime(767):     at dalvik.system.NativeStart.main(Native Method)

这是我的活动：

    public class RatedCalls extends ListActivity {

private static final String LOG_TAG = "RATEDCALLSOBSERVER";
private Handler handler = new Handler();
private SQLiteDatabase db;
private CallDataHelper cdh;
StringBuilder sb = new StringBuilder();
OpenHelper openHelper = new OpenHelper(RatedCalls.this);

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    registerContentObservers();
    Log.d("FILLLIST", "calling from onCreate()");
    cdh = new CallDataHelper(this);
    db = openHelper.getWritableDatabase();

}

@Override
protected void onDestroy() {
    super.onDestroy();
    if (openHelper != null) {
        openHelper.close();
    }
    if (cdh != null) {
        cdh.close();
    }
}

@Override
protected void onPause() {
    super.onPause();
    if (openHelper != null) {
        openHelper.close();
    }
    if (cdh != null) {
        cdh.close();
    }
}

@Override
public void onResume() {

    super.onResume();
    openOrCreateDatabase("calls.db", SQLiteDatabase.CREATE_IF_NECESSARY,
            null);

}

class RatedCallsContentObserver extends ContentObserver {
    public RatedCallsContentObserver(Handler h) {
        super(h);
    }

    @Override
    public boolean deliverSelfNotifications() {
        return true;

    }

    @Override
    public void onChange(boolean selfChange) {
        Log.d(LOG_TAG, "RatedCallsContentObserver.onChange( " + selfChange
                + ")");
        super.onChange(selfChange);
        fillList();

    }
}

private void fillList() {

    String lastDate = cdh.selectDate();

    Cursor cursor = getContentResolver().query(
            android.provider.CallLog.Calls.CONTENT_URI, null,
            android.provider.CallLog.Calls.DATE + " < ?",
            new String[] { lastDate },
            android.provider.CallLog.Calls.DATE + " DESC ");

    Log.d("FILLLIST", "Calling from filllist");

    startManagingCursor(cursor);
    int numberColumnId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.NUMBER);
    int durationId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.DURATION);
    int contactNameId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.CACHED_NAME);
    int numTypeId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.CACHED_NUMBER_TYPE);

    Date dt = new Date();
    int hours = dt.getHours();
    int minutes = dt.getMinutes();
    int seconds = dt.getSeconds();
    String currTime = hours + ":" + minutes + ":" + seconds;

    SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd-yyyy");
    Date date = new Date();

    ArrayList<String> callList = new ArrayList<String>();
    cursor.moveToFirst();

    String contactNumber = cursor.getString(numberColumnId);
    String contactName = cursor.getString(contactNameId);
    String duration = cursor.getString(durationId);
    // String callDate = DateFormat.getDateInstance().format(dateId);
    String numType = cursor.getString(numTypeId);
    stopManagingCursor(cursor);
    ContentValues values = new ContentValues();

    values.put("contact_id", 1);
    values.put("contact_name", contactName);
    values.put("number_type", numType);
    values.put("contact_number", contactNumber);
    values.put("duration", duration);
    values.put("date", dateFormat.format(date));
    values.put("current_time", currTime);
    values.put("cont", 1);
    getBaseContext().getContentResolver().notifyChange(
            android.provider.CallLog.Calls.CONTENT_URI,
            new RatedCallsContentObserver(handler));
    db.insert(CallDataHelper.TABLE_NAME, null, values);
    Toast.makeText(getBaseContext(), "Inserted!", Toast.LENGTH_LONG);
    callList.add("Contact Number: " + contactNumber + "\nContact Name: "
            + contactName + "\nDuration: " + duration + "\nDate: "
            + dateFormat.format(date));

    setListAdapter(new ArrayAdapter<String>(this, R.layout.listitem,
            callList));
    ListView lv = getListView();
    lv.setTextFilterEnabled(true);

    lv.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

            Toast.makeText(getApplicationContext(),
                    ((TextView) view).getText(), Toast.LENGTH_SHORT).show();

        }
    });
}

public void registerContentObservers() {

    this.getApplicationContext()
            .getContentResolver()
            .registerContentObserver(
                    android.provider.CallLog.Calls.CONTENT_URI, true,
                    new RatedCallsContentObserver(handler));

}

public void unregisterContentObservers() {

    this.getApplicationContext()
            .getContentResolver()
            .unregisterContentObserver(
                    new RatedCallsContentObserver(handler));

}
 }

【问题讨论】：

标签： android sqlite android-contentprovider

【解决方案1】：

我认为问题是当你的活动被破坏时你需要关闭数据库。尝试将此添加到您的活动中：

@Override
protected void onDestroy() {
    super.onDestroy();
    if (openHelper != null) {
        openHelper.close();
    }
    if (cdh != null) {
        cdh.close();
    }
}

并将其添加到您的 CallDataHelper 类中：

public void close() {
    // NOTE: openHelper must now be a member of CallDataHelper;
    // you currently have it as a local in your constructor
    if (openHelper != null) {
        openHelper.close();
    }
}

编辑 2： 还将 CallDataHelper 构造函数更改为：

// Declare openHelper as a member variable
OpenHelper openHelper = null;

public CallDataHelper(Context context) {
    this.context = context;
    openHelper = new OpenHelper(this.context);
    this.db = openHelper.getWritableDatabase();
}

这应该会成功关闭由您的两个 OpenHelper 实例创建的数据库连接。

（EDITED 以反映您使用两个 OpenHelper 实例这一事实。）

【讨论】：

我做到了，应用程序运行一段时间后，错误是：12-16 18:09:47.406: ERROR/Database(21184): android.database.sqlite.DatabaseObjectNotClosedException: Application没有关闭此处打开的游标或数据库对象我认为必须关闭游标。如何关闭它？
@psyhclo：你看到我的编辑了吗？您有两个 OpenHelper 实例，每个实例都用于获取数据库连接，因此它们都必须关闭。（您可能想要结合这两个 OpenHelper；这是您的决定。）
方法 close() 必须在哪个类中，OpenHelper 或 CallDataHelper。 openHelper 字段在 CallDataHelper 上，但是当我尝试声明方法关闭时，它说：openHelper 无法解析为变量。并提供创建领域。 Obs：我在 CallDataHelper 上声明了 close() 方法。如果我尝试这样做： public void close() { // 注意：openHelper 现在必须是 CallDataHelper 的成员； // 您当前在构造函数中将其作为本地变量 if (this.db != null) { this.db.close(); }
@psyhclo：回复openHelper，参见上面的编辑2。该编辑包括对构造函数的重写以及 openHelper 成员的声明。 close() 方法也适用于CallDataHelper，用于关闭自己的OpenHelper 实例。（OpenHelper 扩展了SQLiteOpenHelper ，它定义了close()）
还有 onResume() 方法。我该怎么办？您可以使用此代码编辑您的答案吗？因为它返回这个错误：12-16 18:36:19.115: ERROR/AndroidRuntime(26848): java.lang.IllegalStateException: database not open

【解决方案2】：

从字面上理解数据库不是正常关闭的，实际是因为反复实例化你的数据库，或者你已经建立了连接，而你尝试打开另一个连接也不会有异常。所以解决方案是，确保只打开一个连接。

【讨论】：

【解决方案3】：

我怀疑在RatedCalls“会话”期间多次调用fillList()。所以每次你创建一个新的Cursor 实例并在它上面调用startManagingCursor()。这样做你会积累一个游标列表 - ArrayList<ManagedCursor> 准确地说是在 ListActivity 中声明的。通常它们（正在管理的游标）将在ListActivity.onDestroy() 中自动关闭。您能否确认您的RatedCalls 确实通过了onDestroy()。

您是否以某种方式覆盖了RatedCalls 中的ListActivity.onDestroy()。如果是，那你打电话给super.onDestroy()（你应该打电话）？

我不明白在fillList(); 之后在RatedCallsContentObserver.onChange() 中调用onStop() 的目的。我相信 Activity 生命周期回调应该由操作系统仅调用。因此，也许手动调用生命周期回调会以某种方式阻止onDestroy() 被操作系统调用（只是猜测）？

更新：

Dan Breslau 是对的 - 未关闭的是 db 对象。抱歉误导。

【讨论】：

堆栈跟踪显示未关闭的对象是数据库连接本身，通过SQLiteOpenHelper.getWritableDatabase返回。尽管startManagingCursor 确保游标将被正确处理，但我不知道在销毁活动时会自动关闭数据库连接的任何事情。（但是，我的缺乏意识并不是确定的 :-)
@Dan Breslau：天哪，你是对的！！！ 'call.db' 没有关闭！我第一次打开这个问题时，堆栈跟踪的格式不是很好，所以可能我错过了。
@Arhimed 您的回答完全正确。我知道这正在发生，我只是不知道如何解决。事实上，最初的问题是这个 stackoverflow.com/questions/4450778/… ，我们现在的这个问题来自那个问题的答案。我应该怎么做才能停止在 RatedCalls“会话”期间多次调用 fillList()？伙计，你打开了我的心扉！谢谢。
你认为我应该重写 onDestroy() 方法并在 onDestroy 内部执行 stopManagingCursor() 吗？那么你认为我应该在 fillList() 之后调用 onStop() 而不是调用 onDestroy 吗？我要更新我的代码。
@psyhclo：在不了解您的上下文（业务逻辑）的情况下，很难在这里为您提供进一步的建议。例如，您关闭了onStop() 中的数据库，但是您没有在onResume() 中执行任何操作。因此，如果您的活动进入 onStop() -> onResume() 场景，您将获得关闭的数据库，这可能是您意想不到的状态。另外，我仍然不明白你想通过在 fillList() 之后调用 onStop() 来实现什么......