Most voted "java" questions
Use this tag when the question refers to some resource, information, or problem relating exclusively to the Java programming language. Java is a class-based, statically typed, reflective, and execution environment (JRE) language. Java programs are compiled to bytecode and run on a virtual machine (JVM), allowing a "write Once, run Anywhere" philosophy (WORA).
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3
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answer5577
viewsHow to change the default postgresql schema in persistence.xml in a java application
I am developing an application and I have a certain difficulty to change the default scheme of the application. I am using Postgresql in a Java application with JPA and Hibernate as implementation.…
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answers3679
viewsConsume values from a webservice
I have no knowledge in the use of webservice, and I need to use one now to consume data from a database(Normally I would fetch the data directly from the database, but in this case the admin did not…
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answers1253
viewsAttach TXT file using Javamail
I’m using Javamail for sending email, with attachment, on Android. When attaching a file with extension ". txt" it is assigning the content to the body of the email, not as attached file. My file…
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answer2686
viewsPositioning of components using Gridbaglayout
I’m making a panel and I want to have the following layout: The width of the panel takes up the entire width of the frame, and I want to have 4 buttons in the right corner of that panel. I created a…
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answers821
viewsHow to return an imported value from one JSP page to another?
I have two JSP pages: in one it checks a condition of client links, if it has no link, it enters a function that calls another JSP to import client data. He even imports the data but, when he…
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answer1275
viewsRestricting data access with REST
I would like to know if it is possible to restrict access to my application data REST. For example, I have the xml/json that she returns in http://meuapi.com/usuarios, where you return my user list.…
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answer6083
viewsSend an Arraylist of objects to an Activity
How to send an Arraylist of objects to an Activity on Android? ex: I have an Arraylist of Books objects, I want when I click this object arrayList to be passed to another Activity..
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answer1357
viewsDynamic graphical user interface in Java
I need to create something like this: I usually do the GUI’s with the help of the IDE but in this case I can’t(I think), because I need the GUI to repeat an undefined number of times, depending on…
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answers432
viewsCreate a set method for different variables
I’m looking to create a Setter for an object Character, where it will modify the attributes String name, int intellect, int strength and int stamina, but what is the best method to do this? public…
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answer716
viewsHow to communicate between classes?
I’m starting at Javafx and I’m having doubts. The main class creates an Hbox with a button. This button has the action of creating a TableView in the Center of bdPrincipal. Only they are in…
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answer470
viewsProblem with transition animation between Fragments
I’m working on an app that consists of several fragments and decided to put animations between them. Looking, I found that I should use the command setCustomAnimations to get the desired result, but…
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answer1276
viewsMark (colorize) a string to write to the file
My application searches for a few words in a file. When the program recognizes these words (strings), it should mark it. For example: change the font color or change the word background color. Then…
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answers595
views@Named does not work JSF
I am doing a project with jsf 2 and glassfish server when I put @Named in my bean the attributes get null only works with @Managedbean someone has already gone through this problem
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answers1038
viewsJava Timestamp and Mysql Timestamp
Problem: I’m storing a timestamp in MYSQL, but when I reset this timestamp I’m losing the thousandths. Java timestamp with thousandths. MYSQL timestamp without thousandths. Why does this occur? How…
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answer180
viewsGeneric type in Java
I have 3 classes, Expression, Operation, Scalar public abstract class Expression<R extends Expression> { public abstract R calcular(); } public abstract class Operation<T extends…
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answers2485
viewsHow to insert res/string string in the String[]{} array;
I’m trying to put my Strings in an array to use on Adapter and I can’t. I’m doing like this: String cores[] = String[]{getString(R.string.cor1), getString(R.string.cor1)}; but it’s certainly not the…
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answer100
viewsMethod not found using JPA
I created a method for autocomplete. However when I invoke this method it is not found, follow below error: Advertência: /pessoal/cadastrar.xhtml @35,186…
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answers5778
viewsHow to send Jsonobject to a Web Service?
I am trying for the first time to consume a Web Service in my Android application by sending data by JSON format. To accomplish the task I have a class to make the connection. public class…
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answer1286
viewsSocket connection causes an exception on Android
The code below works perfectly when only used with a Jbutton, but when passing to Android happens the exception (Exception). I have located that the error is in clientSocket = new Socket(serverIP,…
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answer439
viewsJframe Paint method does not show the drawings on the screen
I overloaded the method paint and I’m using the Graphics2d class to try to make the drawings, but nothing is being drawn on the screen, I could see with the Debugger that the method is run…
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answer71
viewsFilecopyutils of Spring With strange behavior
I don’t know if anyone here uses the Filecopyutils offered by Spring, but I’m using it in a imaging replication method in my system. It aims to "grab" the images that are in my system’s temp folder…
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answer283
viewsJava JNLP Application and Database
I will start developing a client/server application and in my searches I found Java JNLP. I searched some forums but did not find the answer to this question: Knowing that the application will have…
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answer426
viewsAndroid Mediaplayer class alert: Should have Subtitle controller already set
After I upgraded to Android Kitkat (4.4), a class object MediaPlayer Android generates the following alert on Logcat: Should have Subtitle controller already set As explained in that question of the…
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answers35944
viewsTaking time in format: HOUR:MINUTE:SECOND
I currently use this code: // Pega a hora Date hora = new Date(); hora.getTime(); He returns it to me: Thu Aug 28 21:55:42 BRT 2014 I would like a way to get only hour, minute and second. How to do…
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answers567
viewsJava server disconnects idle users after 5 minutes
I’m using this Java methodology for connection between client and server, I copied it from the internet, and it helped me a lot, but the server allows the user to stay connected while he’s sending…
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answer2814
viewsVia java reflection, set and take values of inherited variables
I have the following class hierarchy (POSTRequestHTTP extends ReqeustHTTP) (RequestHTTP extends ComunicationObjectHTTP ) Assuming that each object can have variables corresponding to an item in a…
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answer1301
viewsMysql Local Database and Online Server Connection
I’m developing an application using Java Swing + Mysql database, but I’m analyzing making an online platform that talks to the local application, using the database to interconnect the data, because…
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answer115
viewsBinding on Spring MVC not working
Well, I have a problem that never occurred to me before related to the Spring MVC Binding. I have a form as below. The bindind "firstName" and "lastname" work well, but already the "logins.email"…
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answer1561
viewsjava.lang.Nullpointerexception Error in JDBC Connection with WS + Postgres
I am creating a WS that connects to a DB Postgresql and performs a query in a single table. I try to run it locally, but the problem is when running the application gives the following error: HTTP…
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answer724
viewsTimetask scheduling Java Tasks
I’m trying to set up some task cycles in Timetask so that it happens every day at a certain time, could someone give me a tutorial or some example that employs this question ? What happens is it…
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answer585
viewsHow do I add a different object to a list whenever using the add?
I’m having trouble adding a different object to a list of objects whenever I use her add, I know what the problem is but I don’t know how to fix it, follow the code List class public class Lista {…
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answer524
viewsEclipse app for iPhone
I’m in need of some help, and I don’t even know what to do. I created a very simple Eclipse Kepler, I put in Google Play and it was great. I would like to know if it is possible and how best to…
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answers3596
viewsLog in with network user (LDAP)
I have an LDAP server in the company and to log into the machine requires a network user. We would like that after the user is already logged in to the machine, when using the network or some…
javaasked 10 years, 2 months ago Fillipe Sanches 45 -
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answers99
viewsPlacing a vector in decreasing order
I need to create a vector of size N but it has to be ordered down only when I do the code always from 0. public int[] vetor_dec (int n) { int[]vetor = new int[n]; for(int i=n;i>vetor.length;i--)…
javaasked 10 years, 2 months ago IMoonBlackI 364 -
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answer301
viewsIllegalargumentexception
I’m developing a project and I’m having a very annoying little problem. It is a WEB system. When I look for a client it fills in all the fields I need correct however, when I look for another client…
javaasked 10 years, 2 months ago Eugenio Michetti 31 -
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answers3039
viewsHow to make a decision structure to close a window?
In the code below, I want you to choose sim the window closes and when choosing não the window remains open. private void formWindowClosing(java.awt.event.WindowEvent evt) { // TODO add your…
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answers7797
viewsRemove duplicate objects from List<Minhaclasse>
Guys is the following, I have a model class with attributes that store data returned from the database. For example: public class RelacaoTransformacao { /** ID do registro no banco de dados. */…
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answer1651
viewsError opening new Activity
I’m picking up here to be able to make the click on a button, open a new Activity. I looked at the Android documentation on Activity, Intent, the methods to create and yet yes, it doesn’t work.…
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answers383
viewsGetting around the problem with hot Java development?
Problem situation: You are developing a website and debugging on it. For example a CRUD of users. For this you are using Javaee 1.7, Eclipse Kepler and Apache Tomcat 7. However, at the development…
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answer6227
viewsHow do you go through a binary tree?
I’m having trouble adding an element to a binary tree because I don’t know how to go... Tree knot public class NodeBinaryTree extends BinaryTree{ NodeBinaryTree left; NodeBinaryTree right; int…
javaasked 10 years, 5 months ago user8278 -
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answers5118
viewsUpload android images to Server folder
How can I upload an android image to a folder on the server? I have the address of the folder that I can use to save image, I am already using this address to be able to grab the images but now I…
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votes3
answers88
viewsProblem receiving random integer values in array
Eclipse does not point out any errors in the code, but does not execute. package gerarOrganizar; import java.util.Random; public class GerarOrganizar { public static void main(String[] args) { int…
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answer1315
viewsCompare prices taking into account units (kg, g)
Hello, I need to compare 2 products, taking into account their weight and values, to know which product is more advantageous to buy. Ex: Rice 5kg - R$ 10,00 Rice 2kg - R$ 6,00 Thinking that you can…
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answer9074
viewsHow to select only one radio button?
In the swing of Java, a user can select more than one radio button simultaneously, so this does not happen, one can do: private void radio1ActionPerformed(java.awt.event.ActionEvent evt) { if…
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answers3349
viewsHow to do Collision in game with Java 2D platform?
I’ve been trying for several days to make a collision method that returns me or tells me the sides of a rectangle that are being collided. I’ve already used the method Intersects but it only returns…
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answer1642
viewsHow to rewind the file pointer correctly in Java?
Actually the problem is quite complex, but I’m going to try to give a notion that I think will be understandable. I have a method in an application that initializes objects to I/O in accordance with…
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answer1352
viewsGenerate 10-character random alphanumeric code
I have today an application that is presenting data divergence because of the return time of a webservice. To get around this we created a code to prevent this particular information from ever…
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answer1857
viewsHow to compare Date to Mysql field
I’m a beginner in Java and I have a table in Mysql that has a date field and the dates are stored in the format yyyy-mm-dd. Now I need to recover only records whose value of the date field is…
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answer1503
viewsHow to modify XML elements with Java?
I have never worked with XML before. I created the following XML configs.xml: <resources> <string name="ip"></string> <string name="username"></string> <string…
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answer561
viewsTwo pages using the same Servlet
I have my main page(index.jsp) uses Servlet for a few little things. Then redirect to the final page.jsp. This page will use Servlet as well, as I need the user to choose the functions (buttons) he…