I know that NULL check for every arguments in a public API is good practice in java. But just curious, do we need do such NULL check in the front of all methods. There are definitely values for doing this: catching error earlier and providing better error message. But is it worthy, I mean doing the same NULL check in all methods seems too tedious. If that is needed, why JVM cannot the job by default.  Please share your thoughts.
31812
I use object != null a lot to avoid . What is an alternative to: if (someobject != null) {     someobject.doCalc(); }
55455
Is it safe to assume that NULL always translates to false in C?  void *somePtr = NULL;  if (!somePtr) {   /* This will always be executed? */ }   Or should an explicit check against the value of NULL be made?
38112
Here's the scenario...    if (entry.Properties["something"].Value != null)   attribs.something = entry.Properties["something"].Value.ToString();   While effective and working correctly, this looks ugly to me.  If I don't check for a null before performing the ToString() then it throws an exception if the property was null.  Is there a better way to handle this scenario?  Much appreciated!
55476
Is there any condition where finally might not run in java? Thanks.
43400
So far I've been using public void run() {} methods to execute my code in Java. When/why might one want to use main() or init() instead of run()?
1079
What are the best practices for using Java's @Override annotation and why?     It seems like it would be overkill to mark every single overridden method with the @Override annotation.   Are there certain programming situations that call for using the @Override and others that should never use the @Override?
65166
It seems like my code works to check for null if I do  if ($tx)    or   if (isset($tx))   why would I do the second one when it's harder to write?
103112
When and why would somebody do the following:  doSomething( (MyClass) null );   Have you ever done this? Could you please share your experience?
1841
What is the use of anonymous classes in Java? Can we say that usage of anonymous class is one of the advantages of Java?
13449
I can't understand where the final keyword is really handy when it is used on method parameters.    If we exclude the usage of anonymous classes, readability and intent declaration then it seems almost worthless to me.   Enforcing that some data remains constant is not as strong as it seems.    If the parameter is a primitive then it will have no effect since the parameter is passed to the method as a value and changing it will have no effect outside the scope.  If we are passing a parameter by reference, then the reference itself is a local variable and if the reference is changed from within the method, that would not have any effect from outside of the method scope.    Consider the simple test example below. This test passes although the method changed the value of the reference given to it, it has no effect.  public void testNullify() {     Collection&lt;Integer&gt; c  = new ArrayList&lt;Integer&gt;();           nullify(c);     assertNotNull(c);            final Collection&lt;Integer&gt; c1 = c;     assertTrue(c1.equals(c));     change(c);     assertTrue(c1.equals(c)); }  private void change(Collection&lt;Integer&gt; c) {     c = new ArrayList&lt;Integer&gt;(); }  public void nullify(Collection&lt;?&gt; t) {     t = null; }
121
I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?
31086
I have a generic method defined like this:  public void MyMethod&lt;T&gt;(T myArgument)   The first thing I want to do is check if the value of myArgument is the default value for that type, something like this:  if (myArgument == default(T))   But this doesn't compile because I haven't guaranteed that T will implement the == operator.  So I switched the code to this:  if (myArgument.Equals(default(T)))   Now this compiles, but will fail if myArgument is null, which is part of what I'm testing for.  I can add an explicit null check like this:  if (myArgument == null || myArgument.Equals(default(T)))   Now this feels redundant to me.  ReSharper is even suggesting that I change the myArgument == null part into myArgument == default(T) which is where I started.  Is there a better way to solve this problem?  I need to support both references types and value types.
95880
What is the use of a Junit @Before and @Test annotations in java? How can I use them with netbeans?
31989
Something that confuses me, but has never caused any problems... the recommended way to dispatch an event is as follows:  public event EventHandler SomeEvent; ... {     ....     if(SomeEvent!=null)SomeEvent(); }   In a multi-threaded environment, how does this code guarantee that another thread will not alter the invocation list of SomeEvent between the check for null and the invocation of the event?
7415
I'm familiar with some of the basics, but what I would like to know more about is when and why error handling (including throwing exceptions) should be used in PHP, especially on a live site or web app. Is it something that can be overused and if so, what does overuse look like? Are there cases where it shouldn't be used? Also, what are some of the common security concerns in regard to error handling?
33203
What exception should I throw if I encounter an illegal state - for instance, an initialization method that should only be called once being called a second time?  I don't really see any built-in exception that makes sense.  This seems like something that should be in the framework - am I not poking in the right spot?
57572
I normally use the following idiom to check if a String can be converted to an integer.  public boolean isInteger( String input ) {     try {         Integer.parseInt( input );         return true;     }     catch( Exception e ) {         return false;     } }   Is it just me, or does this seem a bit hackish?  What's a better way?    See my answer (with benchmarks, based on the  by ) to see why I've reversed my position and accepted  to this problem.  I think this original code will be used by most people because it's quicker to implement, and more maintainable, but it's orders of magnitude slower when non-integer data is provided.