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HashMap get/put complexity
...tant time... but you could have a hash which takes a long time to compute, and if there are multiple items in the hash map which return the same hash code, get will have to iterate over them calling equals on each of them to find a match.
In the worst case, a HashMap has an O(n) lookup due to walki...
Override Java System.currentTimeMillis for testing time sensitive code
...commend that instead of messing with the system clock, you bite the bullet and refactor that legacy code to use a replaceable clock. Ideally that should be done with dependency injection, but even if you used a replaceable singleton you would gain testability.
This could almost be automated with se...
Cannot use identity column key generation with ( TABLE_PER_CLASS )
...
The problem here is that you mix "table-per-class" inheritance and GenerationType.Auto.
Consider an identity column in MsSQL. It is column based. In a "table-per-class" strategy you use one table per class and each one has an ID.
Try:
@GeneratedValue(strategy = GenerationType.TABLE)
...
Shortcut to comment out a block of code with sublime text
...or uncomment the selected text or current line:
Windows: Ctrl+/
Mac: Command ⌘+/
Linux: Ctrl+Shift+/
Alternatively, use the menu: Edit > Comment
For the block comment you may want to use:
Windows: Ctrl+Shift+/
Mac: Command ⌘+Option/Alt+/
...
Best practice for Python assert
...l this an example of using them. This is more an example of properties in and of themselves: docs.python.org/library/functions.html#property
– Jason Baker
Jun 3 '09 at 13:43
3
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What's the use of session.flush() in Hibernate
...) I have class where I am saving object using code id = session.save(obj); and transaction is committed at very next line but obj is not getting saved to DB ,Why? 2) I saved obj using session.save(obj); with commit and while returning I used return obj.getprimaryID(); In this case obj is saved to DB...
“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
...y.
Side effects are propagated to replicas too.
correction: both REPLACE and INSERT...ON DUPLICATE KEY UPDATE are non-standard, proprietary inventions specific to MySQL. ANSI SQL 2003 defines a MERGE statement that can solve the same need (and more), but MySQL does not support the MERGE statemen...
Is it safe to get values from a java.util.HashMap from multiple threads (no modification)?
There is a case where a map will be constructed, and once it is initialized, it will never be modified again. It will however, be accessed (via get(key) only) from multiple threads. Is it safe to use a java.util.HashMap in this way?
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Can I Replace Apache with Node.js?
... have a website running on CentOS using the usual suspects (Apache, MySQL, and PHP). Since the time this website was originally launched, it has evolved quite a bit and now I'd like to do fancier things with it—namely real-time notifications. From what I've read, Apache handles this poorly. I'm wo...
HTML table with 100% width, with vertical scroll inside tbody [duplicate]
How can I set for <table> 100% width and put only inside <tbody> vertical scroll for some height?
13 Answer...