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@Basic(optional = false) vs @Column(nullable = false) in JPA
...and it turns out the annotation is ignored in actual usage (at least for a String field). (e.g. entityManager.persist calls).
So I went to the specification and read up about it.
Here is what the spec has to say:
http://download.oracle.com/otndocs/jcp/persistence-2.0-fr-oth-JSpec/
Basic(optiona...
How can I check the system version of Android?
...s.Build.VERSION.
CODENAME: The current development codename, or the string "REL" if this is a release build.
INCREMENTAL: The internal value used by the underlying source control to represent this build.
RELEASE: The user-visible version string.
...
Check if full path given
...h)
&& !Path.GetPathRoot(path).Equals(Path.DirectorySeparatorChar.ToString(), StringComparison.Ordinal)
The above condition:
does not require file system permissions
returns false in most cases where the format of path is invalid (rather than throwing an exception)
returns true only if pa...
What is the “assert” function?
...e <assert.h>
void analyze (char *, int);
int main(void)
{
char *string = "ABC";
int length = 3;
analyze(string, length);
printf("The string %s is not null or empty, "
"and has length %d \n", string, length);
}
void analyze(char *string, int length)
{
assert(string ...
How to use WPF Background Worker
...vate static BackgroundWorker backgroundWorker;
static void Main(string[] args)
{
backgroundWorker = new BackgroundWorker
{
WorkerReportsProgress = true,
WorkerSupportsCancellation = true
};
...
How to echo with different colors in the Windows command line
...llations) . It uses jscript.net compiler to create an exe capable to print strings with different background/foreground color only for the current line.
@if (@X)==(@Y) @end /* JScript comment
@echo off
setlocal
for /f "tokens=* delims=" %%v in ('dir /b /s /a:-d /o:-n "%SystemRoot%\Microsoft.NET\Fr...
How can I update the current line in a C# Windows Console App?
...nswers for your question. They both involve saving the current output as a string first and padding it with a set amount of characters like this: Console.Write("\r{0}", strOutput.PadRight(nPaddingCount, ' ')); The "nPaddingCount" can be a number that you set yourself or you can keep track of the pre...
Is there a way to escape a CDATA end token in xml?
...DIT2: The same section also reads:
Within a CDATA section, only the CDEnd string is recognized as markup, so that left angle brackets and ampersands may occur in their literal form; they need not (and cannot) be escaped using "&lt;" and "&amp;". CDATA sections cannot nest.
In other words, ...
How do I get a UTC Timestamp in JavaScript?
...o set the timezone of a certain date object is to construct it from a date string that includes the timezone. (I had problems getting that to work in an older Android browser.)
Note that getTime() returns milliseconds, not plain seconds.
For a UTC/Unix timestamp, the following should suffice:
Mat...
How to unzip files programmatically in Android?
...it. The increase in performance is perceptible.
private boolean unpackZip(String path, String zipname)
{
InputStream is;
ZipInputStream zis;
try
{
String filename;
is = new FileInputStream(path + zipname);
zis = new ZipInputStream(new BufferedI...