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How does the “final” keyword in Java work? (I can still modify an object.)
In Java we use final keyword with variables to specify its values are not to be changed.
But I see that you can change the value in the constructor / methods of the class. Again, if the variable is static then it is a compilation error.
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How to copy Java Collections list
...dge of the underlying type. In the case of Strings, which are immutable in Java (and .NET for that matter), you don't even need a deep copy. In the case of MySpecialObject, you need to know how to make a deep copy of it and that is not a generic operation.
Note: The originally accepted answer was...
Creating a custom JButton in Java
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When I was first learning Java we had to make Yahtzee and I thought it would be cool to create custom Swing components and containers instead of just drawing everything on one JPanel. The benefit of extending Swing components, of course, is to have t...
How to represent empty char in Java Character class
I want to represent an empty character in Java as "" in String...
15 Answers
15
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Passing an integer by reference in Python
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Python references are the exact same as Java references. And Java references are according to the JLS pointers to objects. And there is basically a complete bijection between Java/Python references and C++ pointers to objects in semantics, and nothing else describe...
How is CountDownLatch used in Java Multithreading?
Can someone help me to understand what Java CountDownLatch is and when to use it?
12 Answers
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What's the advantage of a Java enum versus a class with public static final fields?
I am very familiar with C# but starting to work more in Java. I expected to learn that enums in Java were basically equivalent to those in C# but apparently this is not the case. Initially I was excited to learn that Java enums could contain multiple pieces of data which seems very advantageous ( ht...
Splitting a Java String by the pipe symbol using split(“|”)
The Java official documentation states:
7 Answers
7
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Performing user authentication in Java EE / JSF using j_security_check
...web application making use of JSF 2.0 (and if any components do exist) and Java EE 6 core mechanisms (login/check permissions/logouts) with user information hold in a JPA entity. The Oracle Java EE tutorial is a bit sparse on this (only handles servlets).
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round up to 2 decimal places in java? [duplicate]
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did you import java.text.DecimalFormat; ?
– amitchhajer
Jul 28 '12 at 13:42
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