Questions tagged as 'java'

Tagged questions
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Problem with JAVA class [closed]

The problem is as follows, I was modifying a java class, and for some reason I had to restart my computer and when I returned to open my java class, my code disappeared and it shows me the following: Someone can tell me what happened and h...
asked by 07.03.2017 / 00:05
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Java zxing helps when reading bar code (java.lang.NullPointerException at com.google.zxing.client.j2se.BufferedImageLuminanceSource.init)

Good afternoon, I'm starting to program with zxing, my question is this: I'm trying to read a barcode, this is my source code: private static String readBarcode(String pathname) throws FormatException, ChecksumException, NotFoundException,...
asked by 06.03.2017 / 20:47
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Is it possible to obtain metadata from a query with JPA?

to obtain the data, I have no problem, I can read and manage them, for this I used: select * from MiTabla; And to read it: em = emf.createEntityManager(); Query query = em.createNativeQuery("select * from MiTabla"); List<Object[]&...
asked by 07.03.2017 / 08:52
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dependency not found maven

Good I have a problem I try to add a dependency, but this marks me the following    [ERROR] /root/evolplus/backendEvol/evolplus/icova/icova-service/src/main/java/com/applying/icova/service/IdeaServiceImpl.java:[10,42] package org.apach...
asked by 14.03.2017 / 02:35
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Problem when validating that only fields with letters exist using regex

I have a method that validates the input formats and inside I have a regular expression that only accepts letters from the a-z. The problem is that I try it with only letters but it does not work, it returns false in the first if. I leave...
asked by 08.02.2017 / 19:14
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Error in bubble ordering

I'm doing a program where the names of students and three grades are recorded, then they have to sort their averages from lowest to highest (I chose the bubble / bubble sorting method) however I get the following error: Grades.java:90: error:...
asked by 10.02.2017 / 03:05
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problem when updating data from a java table after inserting, No operations allowed after connection closed.?

I have a class where I insert data in the db then I update the table but this error appears to me No operations allowed after connection closed. Here I leave the class connection and the class where I insert. //===============clase conexion===...
asked by 08.02.2017 / 21:59
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How can I load more data into a ListView on Android when the end of the list is reached?

Good, in my project I need to upload a news section in my ListView , obviously I can already list them, the problem is that as I have many news what I want is to load them in parts, that is suppose I have 3000 news, What I want is to load...
asked by 15.02.2017 / 17:42
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Launch Window from the Android background

I am trying to launch a window when an action is executed on my app. The problem of this scheme can sometimes be executed in the background, which is why sometimes I will have to launch it without an activity: I am running this fragment: pu...
asked by 16.02.2017 / 14:38
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ViewScoped does not work

I have a Bean that has @SessionScoped and works perfectly, however I want to use @ViewScoped, but when I change the annotation it stops working and it always marks me the Target Unreachable error @ViewScoped I'm importing it with: import ja...
asked by 16.02.2017 / 17:45