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Why does ConcurrentHashMap prevent null keys and values?
...
From the author of ConcurrentHashMap himself (Doug Lea):
The main reason that nulls aren't allowed in ConcurrentMaps
(ConcurrentHashMaps, ConcurrentSkipListMaps) is that ambiguities that
may be just barely tolerable i...
What is the difference between save and insert in Mongo DB?
...orms an update, replacing all field in the existing record with the fields from the document.
Save vs Update :
update modifies an existing document matched with your query params. If there is no such matching document, that's when upsert comes in picture.
upsert : false : Nothing happens when no ...
Flask raises TemplateNotFound error even though template file exists
...emplates by default. So your code should be
suppose this is your hello.py
from flask import Flask,render_template
app=Flask(__name__,template_folder='template')
@app.route("/")
def home():
return render_template('home.html')
@app.route("/about/")
def about():
return render_template('abo...
How can I transform string to UTF-8 in C#?
I have a string that I receive from a third party app and I would like to display it correctly in any language using C# on my Windows Surface.
...
Custom Adapter for List View
... == null) {
LayoutInflater vi;
vi = LayoutInflater.from(mContext);
v = vi.inflate(resourceLayout, null);
}
Item p = getItem(position);
if (p != null) {
TextView tt1 = (TextView) v.findViewById(R.id.id);
TextView tt...
How to create a cron job using Bash automatically without the interactive editor?
...ng the editor (crontab -e). If so, What would be the code create a cronjob from a Bash script?
20 Answers
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How do I reverse an int array in Java?
...egardless, there's no point micro-optimizing until you have clear evidence from profiling that it is necessary/helpful.
– Nicu Stiurca
Apr 7 '14 at 18:11
9
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undefined reference to boost::system::system_category() when compiling
...u 11.10 that uses the Boost libraries. I have the 1.46-dev Boost libraries from the Ubuntu Repository installed, but I get an error when compiling the program.
...
How to echo with different colors in the Windows command line
... your Windows command console.
Windows 10 - Command Line Colors
Starting from Windows 10 the Windows console support ANSI Escape Sequences and some colors by default. The feature shipped with the Threshold 2 Update in Nov 2015.
MSDN Documentation
Update (05-2019): The ColorTool enables you to ch...
WiX tricks and tips
...which goes into more detail and fixes an edge case when properties are set from the command line.
Examples using 1. 2. and 3.
<?include $(sys.CURRENTDIR)\Config.wxi?>
<Product ... >
<Package InstallerVersion="200" InstallPrivileges="elevated"
InstallScope="perMachine" P...