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Access to Modified Closure
...y executing the delegate within the loop.
If you were saving the delegate and using it later, however, you'd find that all of the delegates would throw exceptions when trying to access files[i] - they're capturing the variable i rather than its value at the time of the delegates creation.
In short...
How to append text to an existing file in Java?
...so there are several libraries for this. Two of the most popular are Log4j and Logback.
Java 7+
If you just need to do this one time, the Files class makes this easy:
try {
Files.write(Paths.get("myfile.txt"), "the text".getBytes(), StandardOpenOption.APPEND);
}catch (IOException e) {
//e...
Determining the current foreground application from a background task or service
...es() method as this returns all sorts of system rubbish from my experience and you'll get multiple results which have RunningAppProcessInfo.IMPORTANCE_FOREGROUND. Use getRunningTasks() instead
This is the code I use in my service to identify the current foreground application, its really easy:
Ac...
Copy values from one column to another in the same table
...uestion is:
UPDATE `table` SET test=number
Here table is the table name and it's surrounded by grave accent (aka back-ticks `) as this is MySQL convention to escape keywords (and TABLE is a keyword in that case).
BEWARE, that this is pretty dangerous query which will wipe everything in column te...
How to avoid mysql 'Deadlock found when trying to get lock; try restarting transaction'
...d on every page refresh by a user to keep track of which pages they are on and their last access date to the site. I then have a cron that runs every 15 minutes to DELETE old records.
...
Expression Versus Statement
...something") was enshrined in syntax: one kind of phrase was an expression, and another was a statement, and the parser could tell them apart.
Designers of later languages blurred the distinction: they allowed syntactic expressions to do things, and they allowed syntactic statements that had values....
Reading large text files with streams in C#
I've got the lovely task of working out how to handle large files being loaded into our application's script editor (it's like VBA for our internal product for quick macros). Most files are about 300-400 KB which is fine loading. But when they go beyond 100 MB the process has a hard time (as you...
How does setting baselineAligned to false improve performance in LinearLayout?
I was just building some UI in xml, and Lint gave me a warning and said to set android:baselineAligned to false to improve performance in ListView.
...
Cost of exception handlers in Python
...nt division or modulo by zero
So, as expected, not having any exception handler is slightly faster (but blows up in your face when the exception happens), and try/except is faster than an explicit if as long as the condition is not met.
But it's all within the same order of magnitude and unlikel...
Display milliseconds in Excel
...rs which are timestamps in milliseconds (e.g. 28095200 is 7:48:15.200 am), and I want to make a new column next to it which keeps a running average and displays the time in a hh:mm:ss.000 format.
...