大约有 40,000 项符合查询结果（耗时：0.0786秒） [XML]
When to use AtomicReference in Java?
...ke the key to needing this is because you need to do a "compareAndSet". If all I needed to do was set I wouldn't need the AtomicObject at all because of reference updates themselves being atomic?
– sMoZely
Jan 20 '13 at 21:46
...
Comparing boxed Long values 127 and 128
... If the data type of above variable is primitive (long) then code work for all values.
Java caches Integer objects instances from the range -128 to 127. That said:
If you set to N Long variables the value 127 (cached), the same object instance will be pointed by all references. (N variables, 1 i...
'^M' character at end of lines
...ed to the command-line. I don't know on which OS the SQL script was originally created.
16 Answers
...
What is the difference between concurrency, parallelism and asynchronous methods?
Concurrency is having two tasks run in parallel on separate threads. However, asynchronous methods run in parallel but on the same 1 thread. How is this achieved? Also, what about parallelism?
...
When to use Hadoop, HBase, Hive and Pig?
... too huge.
Coming back to the first part of your question, Hadoop is basically 2 things: a Distributed FileSystem (HDFS) + a Computation or Processing framework (MapReduce). Like all other FS, HDFS also provides us storage, but in a fault tolerant manner with high throughput and lower risk of data ...
Iterate through every file in one directory
...lways include . and .. (the current and parent directories). You will generally not want to work on them, so you can use Dir::each_child or Dir::children (as suggested by ma11hew28) or do something like this:
Dir.foreach('/path/to/dir') do |filename|
next if filename == '.' or filename == '..'
...
jQuery: how to change title of document during .ready()?
...ards is right. It's just a method to let Google read contents that are normally generated with AJAX, via HTML snapshots and some server side modifications.
– Sk8erPeter
Jul 23 '12 at 12:52
...
'IF' in 'SELECT' statement - choose output value based on column values
...tp://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of a null amount:
SELECT id,
IF(type = 'P', IFNULL(amount,0), IFNULL(amount,0) * -1) as amount
FROM report
The part IFNULL(amount,0) means when amount ...
MySQL - Make an existing Field Unique
...e you don't have duplicates first, no?
– William T. Mallard
Apr 16 '14 at 20:04
1
Be sure to make...
python capitalize first letter only
...rn a titlecased version of S, i.e. words start with title case characters, all remaining cased characters have lower case."
– karantan
Jan 3 '17 at 11:34
|...