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In Hibernate Validator 4.1+, what is the difference between @NotNull, @NotEmpty, and @NotBlank?
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@NotEmpty: The CharSequence, Collection, Map or Array object is not null and size > 0.
@NotBlank: The string is not null and the trimmed length is greater than zero.
To help you understand, let's look into how these constraints are defined and carried out (I'm using version 4.1):
The @Not...
How to specialize std::hash::operator() for user-defined type in unordered containers?
To support user-defined key types in std::unordered_set<Key> and std::unordered_map<Key, Value>
one has to provide operator==(Key, Key) and a hash functor:
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Are there any suggestions for developing a C# coding standards / best practices document? [closed]
... 'adopter' in the department) to create a basic (read useful?) C# coding standards document.
26 Answers
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append new row to old csv file python
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I prefer this solution using the csv module from the standard library and the with statement to avoid leaving the file open.
The key point is using 'a' for appending when you open the file.
import csv
fields=['first','second','third']
with open(r'name', 'a') as f:
writer...
Ignore mouse interaction on overlay image
I have a menu bar with hover effects, and now I want to place a transparent image with a circle and a "handdrawn" text over one of the menu items. If I use absolute positioning to place the overlay image above the menu item, the user will not be able to click the button and the hover effect will not...
Calculate a Running Total in SQL Server
...QL Server implementation of the Over clause is somewhat limited.
Oracle (and ANSI-SQL) allow you to do things like:
SELECT somedate, somevalue,
SUM(somevalue) OVER(ORDER BY somedate
ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
AS RunningTotal
FROM Table
SQL Server gi...
How do I load an HTML page in a using JavaScript?
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Even though this is elegant and clean, I suppose it would be better if you actually created the object element through the DOM api.
– David
Jan 21 '15 at 19:13
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Why does ReSharper tell me “implicitly captured closure”?
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The warning tells you that the variables end and start stay alive as any of the lambdas inside this method stay alive.
Take a look at the short example
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
int i = 0;
Random g = new Random();
t...
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.
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Can I use a hash sign (#) for commenting in PHP?
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The answer to the question Is there any difference between using "#" and "//" for single-line comments in PHP? is no.
There is no difference. By looking at the parsing part of PHP source code, both "#" and "//" are handled by the same code and therefore have the exact same behavior.
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