Questions tagged as 'java'

Tagged questions
2
answers

How do I query in a database from a thread? [closed]

A teacher asked to develop a project (a CRUD of cars). I've done the insert, remove, list, and change part. But the list part must be done by a thread (teacher's requirement), where it must list a car every 20 seconds and show in JTextArea...
asked by 02.11.2017 / 22:16
1
answer

Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0

I need to open a file txt and store its information in ArrayList and then make a comparison between what was typed and what has in bad ArrayList to see if the login is right or not. Here is my code: public void actionPerfo...
asked by 04.09.2016 / 21:29
1
answer

Check user status when login

Hello everyone. I'm having a problem in formulating my login screen and would like to ask your knowledge. I'm using Eclipse Mars .1 to program PrimeFaces for visual components and Spring Security for user authentication and authorization....
asked by 24.08.2016 / 11:27
1
answer

How do I pass a url from a server in java

I'm doing testing on my college project, and I have a following problem. I create an object and I pass all its data by the setter and the constructor. When I call Service with the save method, it returns Null and I can not tell if it is working....
asked by 27.08.2016 / 22:29
2
answers

How to avoid memory overflow with recursion

I have a function that is called recursively, how to avoid memory overflow ?? int cont = 0; public void recur() { recur(); cont ++; System.out.println("Chamado: " + cont); }     
asked by 14.10.2017 / 02:24
1
answer

I can not perform the indicated operations [closed]

   Construct a program that, given 2 20-position integer vectors, perform the respective operations indicated by a third 20-position character vector also provided by the user, containing the four arithmetic operations in any combination, storin...
asked by 13.12.2017 / 13:17
1
answer

javax.naming.NoInitialContextException:

I am trying to do a university job with messageria, but my chat is not starting and presenting the following problem: javax.naming.NoInitialContextException: Cannot instantiate class: org.apache.activemq.jndi.ActiveMQInitialContextFactory [R...
asked by 18.11.2018 / 18:13
1
answer

Search in java file

The teacher passed an activity, which is for you to put the files in a txt, read, change and delete ... I am programming the search function, and it is not working. Could you help me? public void searchUser(String login){ String result...
asked by 31.08.2018 / 18:41
1
answer

How to generate a qrCode from a url

url = link Json: { "Id": 10, "BTC": { "value": 0.00000189, "address": "1BUPDHmaAnVDzAq7rBuv1UW1vXFQhhsgZx", "qrcode": "data: image / png; base64, iVBORw0KGgoAAAANSUhEUgAAAMQAAADECAYAAADApo5rAAAAAklEQVR4AewaftIAAAiySURBVO3BQY4kx7IgQdVA3f...
asked by 26.10.2018 / 22:02
1
answer

Hide something HTML (Text, Images) [closed]

Oops, I wonder if you can hide an image / video in an HTML site but the image / video stays there, and if you click on the image / video it can be played in the image / video player As if the image / video was there, being able to be clicked...
asked by 16.10.2018 / 00:12