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If string is empty then return some default value
Often I need to check if some value is blank and write that "No data present" like that:
6 Answers
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Instantiating object of type parameter
...ngBuilder::new);
Alternatively, you can provide a Class<T> object, and then use reflection.
class MyClass<T> {
private final Constructor<? extends T> ctor;
private T field;
MyClass(Class<? extends T> impl) throws NoSuchMethodException {
this.ctor = impl.getCo...
How to generate a Dockerfile from an image?
... -sV=1.36 nginx:latest
It will pull the target docker image automaticlaly and export Dockerfile. Parameter -sV=1.36 is not always required.
Reference: https://hub.docker.com/repository/docker/alpine/dfimage
below is the old answer, it doesn't work any more.
$ docker pull centurylink/dockerfile-from...
Easy idiomatic way to define Ordering for a simple case class
I have a list of simple scala case class instances and I want to print them in predictable, lexicographical order using list.sorted , but receive "No implicit Ordering defined for ...".
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Finding which process was killed by Linux OOM killer
...@jberryman: For some reason, syslog is in /var/log/syslog on some distros, and /var/log/messages on others. I think it's Debian for the former and Red Hat for the latter, BICBW.
– Tom Anderson
Mar 26 '13 at 11:34
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Warning as error - How to rid these
... that basically should not be halting my compile in Visual Studio 2010 and should not be show stoppers, or at least I will fix them later, but I don't want the compile to just error and halt on these kinds of problems.
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Select all 'tr' except the first one
...obody mentioned the use of sibling combinators, which are supported by IE7 and later:
tr + tr /* CSS2, adjacent sibling */
tr ~ tr /* CSS3, general sibling */
They both function in exactly the same way (in the context of HTML tables anyway) as:
tr:not(:first-child)
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Inject errors into already validated form?
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Form._errors can be treated like a standard dictionary. It's considered good form to use the ErrorList class, and to append errors to the existing list:
from django.forms.utils import ErrorList
errors = form._errors.setdefault("myfield", ErrorList())
errors.app...
How to upgrade all Python packages with pip?
...finite potential variations for this. I'm trying to keep this answer short and simple, but please do suggest variations in the comments!
In older version of pip, you can use this instead:
pip freeze --local | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 pip install -U
The grep is to skip editable...
Connecting to Azure website via FTP
...ve you seen this answer? are you using the full credentials including site and a proper ftp client?
– Simon Opelt
Mar 15 '14 at 22:53
7
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