大约有 44,000 项符合查询结果（耗时：0.0488秒） [XML]
Why use AJAX when WebSockets is available?
I've been using WebSockets for a while now, I have chosen to create an Agile project management tool for my final year project at University utilizing Node server and WebSockets. I found using WebSockets provided a 624% increase in the number of requests per second my application could process.
...
JPA CascadeType.ALL does not delete orphans
... all child elements
delete main row
close session
With JPA 2.0, you can now use the option orphanRemoval = true
@OneToMany(mappedBy="foo", orphanRemoval=true)
share
|
improve this answer
...
How can you represent inheritance in a database?
...problems identified for the single table method:
Mandatory attributes can now be enforced with NOT NULL.
Adding a new subtype requires adding a new table instead of adding columns to an existing one.
There is also no risk that an inappropriate attribute is set for a particular subtype, such as th...
Android: Expand/collapse animation
...o I post my actual solution. The main advantage is that you don't have to know the expanded height to apply the animation and once the view is expanded, it adapts height if content changes. It works great for me.
public static void expand(final View v) {
int matchParentMeasureSpec = View.Measur...
Why is my Git Submodule HEAD detached from master?
...date <rebase|merge>
In the common cases, you already have fixed by now your DETACHED HEAD since it was related to one of the configuration issues above.
fixing DETACHED HEAD when .update = checkout
$ cd <submodule-path> # and make modification to your submodule
$ git add .
$ git comm...
How do I get currency exchange rates via an API such as Google Finance? [closed]
Now, I did find the Google Finance API and started looking through that but I found a lot of info about portfolios, transactions, positions & other stuff I know nothing about.
...
Java Reflection: How to get the name of a variable?
...s added to Java 8. Parameter (a special class of local variable) names are now available via reflection. Among other purposes, this can help to replace @ParameterName annotations used by dependency injection containers.
shar...
Why does Javascript getYear() return 108?
...the years since 1900 are counted.
There are potential compatibility issues now that getYear() has been deprecated in favour of getFullYear() - from quirksmode:
To make the matter even more complex, date.getYear() is deprecated nowadays and you should use date.getFullYear(), which, in turn, is not s...
Design Patterns: Factory vs Factory method vs Abstract Factory
...ch concrete implementation it is getting.
Factory Method: Client doesn't know what concrete classes it will be required to create at runtime, but just wants to get a class that will do the job.
AbstactFactory: When your system has to create multiple families of products or you want to provide a l...
Docker build “Could not resolve 'archive.ubuntu.com'” apt-get fails to install anything
...un Docker build on various files which previously worked before, which are now no longer working.
14 Answers
...