Java HashMap get method null pointer exception
If c is not contained in myMap, it will return null, which can’t be unboxed as a boolean. Try : Boolean b = myMap.get(c); if(b != null && b){ …
java
Maven error in eclipse (pom.xml) : Failure to transfer org.apache.maven.plugins:maven-surefire-plugin:pom:2.12.4
You need just to follow those steps: Right Click on your project: Run (As) -> Maven clean Right Click on your project: Run (As) -> Maven install After which, if the build fails when you do Maven Install, it means there is no web.xml file under WEB-INF or some problem associated with it. it really … Read more
What are the shortcut to Auto-generating toString Method in Eclipse?
Eclipse 3.5.2 (and possibly earlier versions) already provides this feature. If you right-click within the editor, you’ll find it under Source -> Generate toString()… To answer your question about whether it’s a bad practice to autogenerate toString(), my opinion is that it is not. If the generated code is very similar to the code you … Read more
How to search a string in another string? [duplicate]
That is already in the String class: String word = “cat”; String text = “The cat is on the table”; Boolean found; found = text.contains(word);
Java collections faster than c++ containers?
This sort of statement is ridiculous; people making it are either incredibly uninformed, or incredibly dishonest. In particular: The speed of dynamic memory allocation in the two cases will depend on the pattern of dynamic memory use, as well as the implementation. It is trivial for someone familiar with the algorithms used in both cases … Read more
Float.NaN == Float.NaN
Use Float.isNaN to check for NaN values.
It is a bad practice to use Sun’s proprietary Java classes?
Because they are internal APIs: they are subject to change in a undocumented or unsupported way and they are bound to a specific JRE/JDK (Sun in your case), limiting portability of your programs. Try to avoid uses of such APIs, always prefer a public documented and specified class.
Eclipse shortcut to run a class
Just use Ctrl + F11. (This is the standard keyboard shortcut to run the class you are working on) I wish this is what you are looking for… buddy.