I run java program with -Xms512m -Xmx1G -Xss1G. I make profiling to verify the memory, so i Track every 10 object allocations. i observe this figure : My question is, why it display me that 117mo represent 40% while i give 1G to memory ? Answer The graph is a percentage of all allocations, not the heap size. …
Tag: java
How to ensure a piece of code is run before exiting a java application
I’m using a licensed API which has a method to acquire/release a license object from a license server that has a finite number of licenses. At the beginning of my application, I call the method to acquire the license, but I want to make sure that this gets released even if my program terminates/crashes …
How to use FXMLLoader.load() – JavaFX 2
I am building a JavaFX application using the JavaFX Scene Builder. The interface was created in the Scene Builder and a FXML file (main.fxml) was created. To use the interface in my application I must load the FXML file using the FXMLLoader, but there is a problem because the load() method returns an Object, …
C compatible printf output for Java
I’d want to convert float/double to string, in Java and C, such that the outputs are both consistent and user friendly. By “user friendly”, I mean the string should be human readable and sound: a maximum number of significant digits, and some automatic switching to scientific notation when a…
Missing return value on Void method?
The following code gives me compile-time errors: missing return value and missing return statement, what value would I return for this Void Type? Answer Void is not void, change it to void type if you don’t want to return anything. Void is a class, void is type. If you want Void, then you need to add re…
Run multi-thread at a time and make thread to run fast
I am trying to run two different threads at a time, but unable to do that. Thread_1 & Thread_2 runs, but difference between them is around 500ms. I am not using wait() or sleep() anywhere in my code. Questions: How to make run thread simultaneously or in parallel? How to make thread run fast? For second q…
Java: Count duplicate tokens on line using Scanner object
Yes this is an exercise from “Building Java Programs”, but its not an assigned problem. I need to write a method that reads the following text as input: And produces the following as output: Now I know I have to use Scanner objects to first read a line into a String, the to tokenize the string. Wh…
Mergesort in java
I am new to Java and have tried to implement mergesort in Java. However, even after running the program several times, instead of the desired sorted output, I am getting the same user given input as …
Many to many with Hibernate and annotations for self referencing
My brain is starting to hurt thinking about this, is it as simple as: Answer Something like:
How do I tell if an empty line has been read in with a BufferedReader?
I’m reading in a text file formated like So I need to keep try of whether I’m in a definition or not based on when I reach those emtpy lines. Thing is, BufferedReader discards n characters, and somehow comparing that empty line to String “” is not registering like I thought it would. H…