containers

Singleton design pattern vs Singleton beans in Spring container

由 前提是你 提交于 2019-11-26 11:13:07
As we all know we have beans as singleton by default in Spring container and if we have a web application based on Spring framework then in that case do we really need to implement Singleton design pattern to hold global data rather than just creating a bean through spring. Please bear with me if I'm not able to explain what I actually meant to ask. user184794 A singleton bean in Spring and the singleton pattern are quite different. Singleton pattern says that one and only one instance of a particular class will ever be created per classloader. The scope of a Spring singleton is described as

'size_t' vs 'container::size_type'

由 青春壹個敷衍的年華 提交于 2019-11-26 11:10:54
Is there is a difference between size_t and container::size_type ? What I understand is size_t is more generic and can be used for any size_type s. But is container::size_type optimized for specific kinds of containers? The standard containers define size_type as a typedef to Allocator::size_type (Allocator is a template parameter), which for std::allocator<T>::size_type is typically defined to be size_t (or a compatible type). So for the standard case, they are the same. However, if you use a custom allocator a different underlying type could be used. So container::size_type is preferable for

What is the best practice of docker + ufw under Ubuntu

由 倖福魔咒の 提交于 2019-11-26 10:29:07
问题 I just tried out Docker. It is awesome but seems not work nicely with ufw. By default, docker will manipulate the iptables a little bit. The outcome is not a bug but not what I expected. For more details you can read The dangers of UFW + Docker My goal is to set up a system like Host (running ufw) -> docker container 1 - nginx (as a reverse proxy) -> docker container 2 - node web 1 -> docker container 3 - node web 2 -> ....... I want to manage the incoming traffic (e.g. restrict access)

Generic iterator

由 橙三吉。 提交于 2019-11-26 10:28:27
问题 I am trying to find a generic way of accessing a set of containers. I have a standard vector and list in addition to another custom list. The custom list defines an iterator; class Iterator: public std::iterator<std::forward_iterator_tag, T> { // ... } Iterator begin() { return (Iterator(root)); } Iterator end() { return (Iterator(NULL)); } with the appropriate operators overloaded. Ideally, I would like to do this; class Foo { public: Foo() { std::list<int> x; std::vector<int> y; custom_list

Is the behaviour of Python&#39;s list += iterable documented anywhere?

由 拟墨画扇 提交于 2019-11-26 09:49:46
问题 It would appear that in Python, list += x works for any iterable x : In [6]: l = [] In [7]: l += [1] In [8]: l += (2, 3) In [9]: l += xrange(5) In [10]: l Out[10]: [1, 2, 3, 0, 1, 2, 3, 4] Is this behaviour documented anywhere? To contrast this with list + x , the latter only works if x is also a list . This is spelled out in the documentation. 回答1: From Guido van Rossum: It works the same way as .extend() except that it also returns self . I can't find docs explaining this. :-( Here is the

How can I keep a container running on Kubernetes?

由 蹲街弑〆低调 提交于 2019-11-26 09:16:13
问题 I\'m now trying to run a simple container with shell (/bin/bash) on a Kubernetes cluster. I thought that there was a way to keep a container running on a Docker container by using pseudo-tty and detach option ( -td option on docker run command). For example, $ sudo docker run -td ubuntu:latest Is there an option like this in Kubernetes? I\'ve tried running a container by using a kubectl run-container command like: kubectl run-container test_container ubuntu:latest --replicas=1 But the

Copy map values to vector in STL

由 爱⌒轻易说出口 提交于 2019-11-26 08:02:31
问题 Working my way through Effective STL at the moment. Item 5 suggests that it\'s usually preferable to use range member functions to their single element counterparts. I currently wish to copy all the values in a map (i.e. - I don\'t need the keys) to a vector. What is the cleanest way to do this? 回答1: You can't easily use a range here becuase the iterator you get from a map refers to a std::pair, where the iterators you would use to insert into a vector refers to an object of the type stored

ItemContainerGenerator.ContainerFromItem() returns null?

由 点点圈 提交于 2019-11-26 07:46:41
问题 I\'m having a bit of weird behavior that I can\'t seem to work out. When I iterate through the items in my ListBox.ItemsSource property, I can\'t seem to get the container? I\'m expecting to see a ListBoxItem returned, but I only get null. Any ideas? Here\'s the bit of code I\'m using: this.lstResults.ItemsSource.ForEach(t => { ListBoxItem lbi = this.lstResults.ItemContainerGenerator.ContainerFromItem(t) as ListBoxItem; if (lbi != null) { this.AddToolTip(lbi); } }); The ItemsSource is

How can I store objects of differing types in a C++ container?

由 白昼怎懂夜的黑 提交于 2019-11-26 07:37:08
问题 Is there a C++ container that I could use or build that can contain, say, int and string and double types? The problem I\'m facing is that whenever I try to populate, say, a map, vector or list with, say, the following: int x; string y; double z; I\'m restricted with the format: list<int> mycountainer; vector<string> mycontainer; which forces mycontainer to only consist of one type. Before anyone suggest generics, that wouldn\'t work either since the standard vector and list containers that

How to change the size of the font of a JLabel to take the maximum size

由 断了今生、忘了曾经 提交于 2019-11-26 04:45:24
问题 I have a JLabel in a Container. The defaut size of the font is very small. I would like that the text of the JLabel to take the maximum size. How can I do that? 回答1: Not the most pretty code, but the following will pick an appropriate font size for a JLabel called label such that the text inside will fit the interior as much as possible without overflowing the label: Font labelFont = label.getFont(); String labelText = label.getText(); int stringWidth = label.getFontMetrics(labelFont)
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