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Java null check why use == instead of .equals()
In Java I am told that when doing a null check one should use == instead of .equals(). What are the reasons for this?
16 An...
org.hibernate.MappingException: Could not determine type for: java.util.List, at table: College, for
... @All: Nobody told me about, the utter code misplacement in Main.java :(
– user405398
Sep 22 '10 at 23:59
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show 4 more comments
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How can I count the number of matches for a regex?
...tcher.find() does not find all matches, only the next match.
Solution for Java 9+
long matches = matcher.results().count();
Solution for Java 8 and older
You'll have to do the following. (Starting from Java 9, there is a nicer solution)
int count = 0;
while (matcher.find())
count++;
Btw,...
Java code for getting current time [duplicate]
I am searching code in java for fetching or synchronizing my local PC system time into my application.
14 Answers
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Difference between JAX-WS, Axis2 and CXF
... Thanks, helps alot. So for the basic web service stuff i can just use java 1.6 to implement.And was their a implementation of jax-ws in java 1.5? Or it was added after 1.6? If i need additional features i can go with CXF?
– Maverick Riz
Jul 19 '12 at 18:52...
make arrayList.toArray() return more specific types
...yList<String>();
String[] a = list.toArray(new String[0]);
Before Java6 it was recommended to write:
String[] a = list.toArray(new String[list.size()]);
because the internal implementation would realloc a properly sized array anyway so you were better doing it upfront. Since Java6 the em...
Determine if a String is an Integer in Java [duplicate]
...eturn false;
}
return true;
}
Alternatively, you can rely on the Java library to have this. It's not exception based, and will catch just about every error condition you can think of. It will be a little more expensive (you have to create a Scanner object, which in a critically-tight loop ...
Run Java Code Online [closed]
codepad.org allow you to run C,C++,D etc code online but not Java... is there a site that I can use for Java?
9 Answers
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Why use @PostConstruct?
In a managed bean, @PostConstruct is called after the regular Java object constructor.
5 Answers
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How can I lookup a Java enum from its String value?
...says that static initialization occurs from top to bottom: docs.oracle.com/javase/specs/jls/se7/html/jls-8.html#d5e12267
– Selena
Oct 15 '14 at 18:22
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