Android-单元测试以检查光标是否固定

Question

我遇到此错误：

android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 2062): Could not open database
#################################################################
Error Code : 2062 (SQLITE_CANTOPEN_EMFILE)
Caused By : Application has opened too many files. Maximum of available file descriptors in one process is 1024 in default.
(unknown error (code 2062): Could not open database)
#################################################################

我认为发生这种情况是因为我忘记了在方法中关闭游标。为节省起见，我想在单元测试中重现此问题。但是我不知道如何检查现有的连接/光标数量以及如何断言该异常

public int getServicesAmount() {
    int servicesAmount;
    AppDbHelper dbHelper = new AppDbHelper(context);
    SQLiteDatabase db = dbHelper.getReadableDatabase();

    String[] columns = {/* some columns */};

    Cursor cursor = db.query(
            AppEntryContract.ServiceEntry.TABLE,
            columns,
            null,
            null,
            null,
            null,
            null
    );
    servicesAmount = cursor.getCount();
    // here I should close the cursor
    return servicesAmount;
}

这是到目前为止的单元测试

 @Test
public void connectionNotClosed() throws Exception {

    try
    {
        Storage storage = new Storage(RuntimeEnvironment.application);
        for(int i = 0; i <= 1025; i++) {
            storage.getServicesAmount();
        }
        Assert.fail();
    }
    catch(ArithmeticException e)
    {
        System.out.println("---------------------------------------------");
        System.out.println("----------------- SUCCESS -------------------");
        System.out.println("---------------------------------------------");
        assertThat("",is(""));
    }
}