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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answer37
viewsError while consuming service using Volley
I am developing an application in Android Studio in which consumes a service I created in Play Framework. This is my service route: GET…
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answer69
viewsActivity closes when calling Oncreate method to create Spinner
I have a Spinner that if I invoke his creative method on Oncreate, the program shuts down abruptly. I think q must be something null or some variable of another scope, because if I call the method…
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answer58
viewsProblem when performing a select with JPA
I’m facing a bug I can’t figure out a solution. When I do a persist and then select the received and normal result, but when doing an update and after that select instead of displaying the updated…
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answer84
viewsError when starting spring
First of all, I use java 9 and apache Tomcat 9 When I start the application this error happens: 18:00:46,804 ERROR DispatcherServlet:492 - Context initialization failed…
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answer22
viewsHow to change decimal delimiter on primfaces chart?
I’m having a problem that my decimal delimiter on graph component of the primefaces is set to be ., how do I change to ,?…
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answer115
viewsTxt displays duplicate information
What this application does: the user has to choose the right answer to the question. I have only put a question for now. After save the answer (is inside a . txt) he can see result. And there’s the…
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answer100
viewsFloat with Spring null value
I have an application with Spring Data. Calling the Spring findAll() method, there are null values in the database. When setting the object the field comes with null value triggering the error…
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answer666
viewsProblem starting java program with windows
Important explanations: I have an application created in JAVA; An "EXE" executable was created using Launch4j; I have the need to run this application after windows startup. FIRST ATTEMPT A shortcut…
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answer66
views.txt shows no old messages, takes only the last and displays
What the implementation is: volley the result of a question (Qtd hit and Qtd error) and showcase on another screen. What the app is doing: saves everything and only displays the result of the moment…
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answer2192
viewsJava Web Service SOAP with objects
Hello, I am learning to use web-services and I stopped with a problem, maybe it is something silly, but I did not find solution, I am hosting my application in Heroku and I will leave here the…
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answers680
viewsHibernate jumping id sequence
I managed a project by JHipster who uses Java, Spring and Hibernate in backend, I created a class as follows: Liquibase: <changeSet id="20160504131602" author="jhipster"> <createTable…
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answer148
viewsConvert project to Maven with EAR, which best way?
Hello, I would like to know what would be the best way to convert this project into Maven so that it can recognize the "Shared.War", "facede.jar" and be packaged as ". ". I’ve done some conversions…
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answers106
viewsDefinition of WSDL raising exception
Hello, I’ve been trying for a few days to define a wsdl of a component that uses SOAP for a SOA project that mixes several types of services, integrating them with Camel. But I’m caught in a problem…
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answers217
viewsDoubt when saving image in mysql database
Good evening, here’s the deal: I have a Jlabel = jlImage, where an image is loaded as shown by the btnCaminhoImagemActionPerformed method. But I want to use the save button to insert the image in…
javaasked 8 years, 5 months ago Carlos Leandro Ferreira de Alm 339 -
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answer480
viewsView Page Android - grab list of images within the App and set on the View page.
Guys I have a problem when I need to set my variable in View Page. I have an Activity that searches the images inside the App and arrow in an Array String, until then it is all correct, I use the…
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answer54
viewsProblem starting Javafx application
Hello, I’m trying to create a simple application in Javafx, everything was working until suddenly started giving problem when trying to start the program. You’re making the following exception:…
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answers56
viewsCreate xml elements inside the activity_controller
I have a program that has a dropdown with 3 options. (Option 1 has value 1, Option 2 value 2 and option 3 value 3). Depending on the selected option, I need to create Textedits below this dropdown.…
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answers45
viewsMenu Firefox Javafx
Good afternoon, could someone provide me an idea how to create this Javafx menu ?…
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answer194
viewsJPA merge/persist
I have the following structure: A.class B.class C.class D.class A.class contains many B.class containing a D.class C.class contains many D.class containing a B.class Whereas D.class is persisted in…
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answer896
viewsDoubt with business rule between student class and class
I have a question in a code, I am new in programming, if anyone can help me, I will be grateful. The student class will receive the student’s name; Class class will receive a collection of students…
javaasked 8 years, 5 months ago user45813 -
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answer2046
viewsKotlin vs java performance and is it worth trading java for Kotlin?
The running performance on android (I refer to the speed of the application and not the build speed, because benchmarks on powerful machines showed the slower Kotlin than java in terms of…
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answer95
viewsDeploying non-JDBC-compliant driver class org.postgresql.Driver
Good night to you all. I have a problem I believe is simple to solve. in IDE(netbeans) the project runs smoothly, but when I publish in jbossit is the following error: 18:54:40,111 INFO…
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answer490
viewsSpring Security Permissions
I am developing a system for my college TCC. I am creating the user authentication part. I wonder if someone has a simple example of Spring Security configuration of users who have more than one…
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answer112
viewsHow to consult the firebase database via an HTML or PHP page
I have a database already created already receives data in firebase, that same data is sent from my App. The possibility of consulting this same data in firebase through a page made in HTML or PHP…
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answers225
viewsWhen to use the Builder-based model object builder instead of passing parameters?
When you have a Builder for creating a template object the method build() is responsible for creating this object, in many examples and materials I have seen this creation made in two ways: Using…
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answer72
viewsA function run infinitely in Servlet
I have a Servlet application that constantly receives POST requests, I do the data processing and processing normally in its due Java classes, however one of my applications it should not be rotated…
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answer1711
viewsAndroid - How to call a method from another class from onCreate()?
I am very new on Android. So if you can explain the logic behind the problem I would appreciate it. It would help me understand the problem and see how I could solve it if it happens again. In…
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answers51
viewsAndroid storage
I am starting in the universe of Android, and I have the following question: In a login system, which type of storage should I use to persist the data of the user who logged in to that session, and…
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answer43
viewsproblems with trying to get the order id
well I am trying to register an order, however I have two tables, order and ordering, and a screen where I fill all the information and click to complete. First the application makes an Insert in…
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answer60
viewsApprovals, reprovacations and room-Java media
I need to receive 30 bills and return the number of approvals, reprobations and the average of the room. I tried the following: public class notas { public static int aprovacoes; public static int…
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answers37
viewsError opening the eclipse
This problem is occurring after I changed the jdk was with 1.7 and started using 1.8. Does anyone know the solution? Follow message when trying to open eclipse. java was started but returned exit…
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answer1042
viewsHow to create an automatic click (tap) on your Android screen?
I am a beginner and I am trying to make a game and wish that automatically, during the execution of the app occurs a click on specific area of the screen, as if the user had done. 1 - I can simulate…
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answer89
viewsdate problem
in my application when I make a request for sale, should inform the date of the order and the date of issue, the date of the order I pick up automatically, already the date of issue should be filled…
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answer58
viewsgettext() returns null when trying to read the typed value in an Edittext
I have an Edittext field and want to save the Text contained in it by pressing a button i tried to do it using the following code but the string remains null public void Botao (View view) {…
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answers121
viewsHelp with parameters in Jasper Reports
I wonder if there is a way I can pass a parameter with a value obtained in the parent report query to a subreport, and use this value la in the subreport... :D
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answer75
viewsIs it possible to create a hybrid application with Angularjs as front, and java as backend?
I am new to front programming, mainly in Angularjs. So I come to ask you if it’s possible to create an app, either with Ionic or phonegap, with the angular being front-end and the java back-end…
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answers64
viewsCreate application to communicate with SYSFAN motherboard output
Hi, I’m in need of a library idea, language, code, that you know where I can write the code to communicate with the Fan output from the motherboard. To better understand the idea, there are…
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answers51
viewsHow to generate multiple buttons with the same variable and catch them separately
Hello, I’ll put the important part of the code here and then I’ll explain what I want to do. Main: public static JButton sala; public static int contagemTurmas = 0; botaoSalvar.addActionListener(new…
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answer1748
viewsHow to add scrollbar in Jpanel?
I would like to add a scroll bar to a Jpanel that uses Absolute Layout. package Default; import javax.swing.JFrame; import javax.swing.border.EmptyBorder; import java.awt.Dimension; import…
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answers120
viewsClose java(.jar) specific program with C++
I have a program running in java, I would like to close it if necessary with a monitor written in C++. As in taskmgr only java.exe appears, how to close the specific.jar program?
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answer162
viewsScroolview problems in Android Studio
Good morning, I’m new in Android programming and I’m trying to create a program that based on a subject that the user chooses, will open a certain screen, everything I’ve been doing was based on…
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answers597
viewsHow does the equals() method work in Java?
At the time I will use the method equals() I place an object of the type Person and it works, because? How it works being that the object I passed is not the type Object? I know all this has to do…
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answer228
viewsHow to use Jprogressbar in Arraylist comparison classes?
I have a class that compares two ArrayList, one with information added by the user and the other with database query. After the query is done, I send this object to another class that performs the…
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answers40
viewsReturning the total with the date in a query with the SUM
I need to return a sum of the value field of the table m and together with it the date of the initial field of the field sale_date, and showing Aggregate Function error: SELECT sum(m.value),…
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answers89
viewsView HTTP Request Time and Java Process in Eclipse
I would like to calculate and visualize the time and resources spent when the JAVA server receives a request, from the moment it receives to the moment in response.
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answer401
viewsHow to join two Arrays?
Hello, I have the following problem I have an Arraylist that returns several small arrays of two positions String[] temp = new String[2]; and has the saved arrayList adds several "temp"; ArrayList…
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answer52
viewsDoubt (hibernate) - JSF
I’m making an employee register, and this register already has departments registered in the bank. So, at this point I walk through the database to present the data in the view, but when I finish…
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answers1583
viewsJava - Missing Artifact com.sun:tools:jar:0 (POM.xml)
I’m making that mistake on my POM.xml. Would anyone know what to say? <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"…
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answers130
viewsHow to remove the onesignal icon?
Galera has an app on Android Studio and it has notifications from One Signal, is working normal, I managed to change the default icon to one of my choice, but it is my icon and another small icon…
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answer43
viewsIonic Authentification
I’d like some help, because I’ve been trying for days to think of a way to do this, but I still can’t quite figure out how to do it. I have an Ionic application, where access happens through a login…