Questions tagged as 'java'

Tagged questions
3
answers

Query database every X seconds

What I need to do is the following, I do not know why but if you update a data in database does not paint it at once in my view, I must run my project to see the update of the data. I would like to do a method that every 5 seconds consult the da...
asked by 06.06.2016 / 19:10
1
answer

the main class was not found

Hello at the moment of compiling the TEST FILE in the console with javacc I get it    "Error: the main class was not found or loaded   ProjectCompi.java " This is my JJ FILE: >PARSER_BEGIN(ProyectoCompi) >class ProyectoCompi...
asked by 26.06.2016 / 23:03
1
answer

Doubt about error type of data and values in Java

I am learning how to program and I have the following exercise. I have to initialize different variables with the type of data that contains the smallest number of bits for said variable, at a certain value that they have given us. The fact is t...
asked by 11.02.2018 / 20:16
1
answer

Expression of type List needs unchecked conversion to conform to List

I have a repository class that implements another method to obtain all my clients @Repository public class ClienteRepositoryImpl implements ClienteRepository{ private EntityManager em; @Override @Transactional(readOnly = true)...
asked by 22.02.2018 / 15:05
3
answers

How to know what files I have in my ArrayList in java?

I have a ArrayList<String> which I love files with extensions .pnd .ana .cnf with their respective names. What I need to know is how to ask if there are three extensions within the ArrayList, only the extensions and NO the ful...
asked by 12.08.2017 / 04:36
2
answers

Retrieve a variable sent to server

From a JavaScript function I sent a String with the following method: zAu.send(new zk.Event(zk.Widget.$('$nuevaPeticion'), 'onNueva', resultado, {toServer:true})); The string I send is the result. My intention now is to collect that String...
asked by 21.09.2018 / 12:02
1
answer

Regex to replace special characters - JAVA

I have this function in Java, quite dirty and a little bad, what it does is pick up a word and replace the 'special' characters, I would like to know another more ergonomic way to do it, if it is with a Regex or with something else. private St...
asked by 26.09.2018 / 11:54
2
answers

Memory Regions of the JVM What is the difference between the Heap and Stack memory?

When a java application is started, you can set the memory boot directives with -Xms and Xmx to define with what minimum memory the application starts and which is the maximum it can occupy. My query is What kind of memory is affected by these p...
asked by 27.09.2018 / 20:01
1
answer

Problem in Java! (impression of a value returned within an if)

It turns out that I have some problem at the time of continuing with my code which is a task of u, I usually use Javascript, and I'm new to Java, so I do not know many basic things, but having experience programming in another language such as J...
asked by 04.09.2018 / 22:40
2
answers

How to perform an action when you stop writing in a JText Field in Java Swing? (something like Java's onChange script)

I have a JText Field where you can type the amount of a product and I want to call a function after filling the JText Field to be able to so convert the value entered in currency. I did not find something similar in Key events and used keyPre...
asked by 11.09.2018 / 00:05