Short answer: Right-click on the class that contains the main method. Click on “Run As”. Click on “Java Application”. The keyboard shortcut is: Shift+Alt+X J (while holding Shift and Alt, press X; then release Shift and Alt and press J). Long answer: To be honest, I am not 100% sure why this problem happens. It … Read more
What is wrong with the code there are lots of error while debugging. I am writing a code for a singleton class to connect with the database mysql. Here is my code I am new to java. Please help.
but as for this method, I don’t understand the purpose of Integer.MAX_VALUE and Integer.MIN_VALUE. By starting out with smallest set to Integer.MAX_VALUE and largest set to Integer.MIN_VALUE, they don’t have to worry later about the special case where smallest and largest don’t have a value yet. If the data I’m looking through has a 10 … Read more
This is really non-trivial. There are two ways to sandbox Python. One is to create a restricted environment (i.e., very few globals etc.) and exec your code inside this environment. This is what Messa is suggesting. It’s nice but there are lots of ways to break out of the sandbox and create trouble. There was … Read more
I have a string like I would like to print it this way Can anybody help me?
I think it’s a historical thing – if a package is introduced as an addition to an existing JRE, it comes in as javax. If it’s first introduced as part of a JRE (like NIO was, I believe) then it comes in as java. Not sure why the new date and time API will end up as javax following this logic … Read more
Since Java 5 you can use Arrays.toString(arr) or Arrays.deepToString(arr) for arrays within arrays. Note that the Object[] version calls .toString() on each object in the array. The output is even decorated in the exact way you’re asking. Examples: Simple Array:String[] array = new String[] {“John”, “Mary”, “Bob”}; System.out.println(Arrays.toString(array)); Output:[John, Mary, Bob] Nested Array:String[][] deepArray = new String[][] {{“John”, “Mary”}, {“Alice”, “Bob”}}; System.out.println(Arrays.toString(deepArray)); //output: … Read more
The type char is a primitive — not an object — so it cannot be dereferenced Dereferencing is the process of accessing the value referred to by a reference. Since a char is already a value (not a reference), it can not be dereferenced. use Character class:
First, it’s kind of weird, to see you run java -jar “app” and not java -jar app.jar Second, to make a jar executable… you need to jar a file called META-INF/MANIFEST.MF the file itself should have (at least) this one liner: Where com.mypackage.MyClass is the class holding the public static void main(String[] args) entry point. Note that there are several ways to … Read more
Could it be that you’re using a 32-bit jvm on that machine?