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What's the difference between JPA and Hibernate? [closed]
I understand that JPA 2 is a specification and Hibernate is a tool for ORM. Also, I understand that Hibernate has more features than JPA 2. But from a practical point of view, what really is the difference?
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Difference between HashMap, LinkedHashMap and TreeMap
What is the difference between HashMap , LinkedHashMap and TreeMap in Java?
I don't see any difference in the output as all the three has keySet and values . What are Hashtable s?
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what is the difference between a portlet and a servlet?
I am asked to work on portlets and portals.
5 Answers
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Why doesn't C++ have a garbage collector?
...ood discussion of the topic here.
General overview:
C++ is very powerful and allows you to do almost anything. For this reason it doesn't automatically push many things onto you that might impact performance. Garbage collection can be easily implemented with smart pointers (objects that wrap po...
Can Android Studio be used to run standard Java projects?
For those times when you want to isolate the Java and give it a quick test..
13 Answers
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C++ valarray vs. vector
I like vectors a lot. They're nifty and fast. But I know this thing called a valarray exists. Why would I use a valarray instead of a vector? I know valarrays have some syntactic sugar, but other than that, when are they useful?
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Difference between a Structure and a Union
Is there any good example to give the difference between a struct and a union ?
Basically I know that struct uses all the memory of its member and union uses the largest members memory space. Is there any other OS level difference?
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Is there more to an interface than having the correct methods
...rk.
Another reason is, for example, if you want to create a list of boxes and perform some operation on each one, but you want the list to contain different kinds of boxes. On each box you could do:
myBox.close()
(assuming IBox has a close() method) even though the actual class of myBox changes ...
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....
Running Internet Explorer 6, Internet Explorer 7, and Internet Explorer 8 on the same machine
Like everyone else, I need to test my code on Internet Explorer 6 and Internet Explorer 7. Now Internet Explorer 8 has some great tools for developer, which I'd like to use. I'd also like to start testing my code with Internet Explorer 8, as it will soon be released.
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