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How to synchronize a static variable among threads running different instances of a class in Java?
...nized static method. This synchronizes on the class object.
public class Test {
private static int count = 0;
public static synchronized void incrementCount() {
count++;
}
}
Explicitly synchronize on the class object.
public class Test {
private static int count = 0;
...
How to remove all the null elements inside a generic list in one go?
...drew: according to MSDN, RemoveAll does not take null. I think I also have tested that. A comment makes sense though.
– Tobias Knauss
Jul 17 '16 at 11:25
1
...
Store query result in a variable using in PL/pgSQL
...
I think you're looking for SELECT INTO:
select test_table.name into name from test_table where id = x;
That will pull the name from test_table where id is your function's argument and leave it in the name variable. Don't leave out the table name prefix on test_table.nam...
Is git not case sensitive?
...
In my scenario I had two folders tests and Tests which showed as two separate folders in Github but a single Tests folder in Windows. My aim was to combine them both into tests.
I used the following approach:
Create a new folder temp
Copy all content from...
INNER JOIN vs LEFT JOIN performance in SQL Server
...icient indexes to cover the query.
Consider this example:
CREATE TABLE #Test1
(
ID int NOT NULL PRIMARY KEY,
Name varchar(50) NOT NULL
)
INSERT #Test1 (ID, Name) VALUES (1, 'One')
INSERT #Test1 (ID, Name) VALUES (2, 'Two')
INSERT #Test1 (ID, Name) VALUES (3, 'Three')
INSERT #Test1 (ID, Na...
How to test multiple variables against a value?
...wn (False if 0, True otherwise).
You can shorten that using a containment test against a tuple:
if 1 in (x, y, z):
or better still:
if 1 in {x, y, z}:
using a set to take advantage of the constant-cost membership test (in takes a fixed amount of time whatever the left-hand operand is).
When ...
Using semicolon (;) vs plus (+) with exec in find
... called once per file (or other filesystem object) found:
$ find . -name 'test*' -exec echo {} \;
./test.c
./test.cpp
./test.new
./test.php
./test.py
./test.sh
With a plus, the command echo is called once only. Every file found is passed in as an argument.
$ find . -name 'test*' -exec echo {} \...
Evaluate empty or null JSTL c tags
... JSTL?
You can use the empty keyword in a <c:if> for this:
<c:if test="${empty var1}">
var1 is empty or null.
</c:if>
<c:if test="${not empty var1}">
var1 is NOT empty or null.
</c:if>
Or the <c:choose>:
<c:choose>
<c:when test="${empty var1...
What's the difference between [ and [[ in Bash? [duplicate]
...ked at Conditional Expressions section and it lists the same operators as test (and [ ).
4 Answers
...
Check if a string is html or not
...ter regex to use to check if a string is HTML is:
/^/
For example:
/^/.test('') // true
/^/.test('foo bar baz') //true
/^/.test('<p>fizz buzz</p>') //true
In fact, it's so good, that it'll return true for every string passed to it, which is because every string is HTML. Seriously, ...