Questions tagged as 'java'

Tagged questions
2
answers

Problem with commandButton in Netbeans

I have a problem ... I do not understand why the buttons do not appear in the view :( <h:body> <h:form id="frmPrincipal"> <p:dataTable> <p:column headerText="Boton1">...
asked by 23.01.2017 / 01:24
3
answers

I want to make a sales system in java, for a liquor store and keep a lot of data with the passage of time, which database should I use? [closed]

It's my first job, I'm still a student, I want to make sales software for a liquor store, with a local database, the language I use is java and I do not know which database to use, in the long run many will be saved data and I do not want to be...
asked by 10.04.2017 / 16:01
1
answer

Restart an auto_increment using java [duplicate]

Good afternoon I'm creating a website with java I'm uploading an excel file to a jsp to save it in MySQL at the moment I am reading the file in it I am saving it in an ArrayList to save it in MySQL alphabetically ordered, the table in MySQL wh...
asked by 05.12.2016 / 22:39
3
answers

JPA Loading a list in datatable [closed]

Good morning, In one method I am bringing two lists with the work order parameter ( idOrdentrabajo ) the first list loads me correctly in a datatable but the second list gives me the following error.    Information: ERROR: Query argu...
asked by 12.01.2017 / 12:36
2
answers

In Java, arguments are passed by value or by reference?

I always thought that in Java the parameters are passed by reference in the case of objects and by value in the case of primitive types. But there are sites where it is said that all parameters are passed by value, for example, here (in Eng...
asked by 18.12.2015 / 22:12
4
answers

How can I create a method to change the value of an attribute?

Write a class called MiNumero in Java. The methods of the class should be: Constructor without parameters (will set the number to zero) Constructor with integer parameter (will assign that value to the number) Method cambiaNume...
asked by 21.10.2017 / 21:16
4
answers

How to execute java function only once?

Hi, I would like to know how in java I can execute a method only once (the first time I open the program), and then independently of all the times I decide to open it, I will not run again. I hope you understand. Thanks and regards.     
asked by 06.06.2018 / 04:11
1
answer

What to do so that the data remains recorded in the program with Eclipse without having to install MySQL [closed]

So far I've used MySQL to save the data locally from my program in Java using Eclipse and WindowsBuilder . But, I would like to know how to save the data in the same program without installing MySQL in the co...
asked by 15.01.2017 / 02:25
1
answer

In what cases is it necessary to call Garbage Collector manually through the System.gc () method in JAVA?

I do not know if in complex programs like IDEs: IntelliJ, eclipse, netbeans among others occupy it at some point to more efficiently release system resources manually (speaking clearly of their source code of those IDEs and not at the moment of...
asked by 20.11.2018 / 14:52
1
answer

What does this code mean and what do you want to do with this expression? [closed]

// server refers to an attribute of type Server that is a class server.clients .stream() .filter(h -> (destinatario.equals(h.getIdentificador()))) .forEach((h) -> h.enviarMensaje(lista));     
asked by 12.03.2017 / 11:43