Java is a high-level, platform-independent, object-oriented programming language originally developed by Sun Microsystems. Java is currently owned by Oracle, which purchased Sun in 2010.

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Using XML to store and edit data records in Java

I want to use XML to store data for an assignment . In this Java assignment I'll get data from the user in form of lines in a file below INSERT INTO student(id,name,family,isMale) VALUES ...
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1answer
22 views

Java Non-static method cannot be referenced from a static context

I want to make a reservation system for a camping. I also wanna know how many people already have made a reservation. Im using the iterator but I get the error "Non-static method getPersons() cannot ...
3
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1answer
305 views

Scheduling a few CPU-intensive tasks

I need to schedule a small number of CPU-intensive tasks to run every so often, reading from shared data and writing to dedicated buffers. I don't necessarily want to roll my own scheduling, but am ...
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1answer
331 views

MVC: How to Implement Linked Views?

I'm developing a java application to visualize time series. I need (at least) three linked views, meaning that interaction with one of them updates the others. The views are: A list represents the ...
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votes
0answers
26 views

Monitoring an .mp2 file in Linux to see if it's used by another process

I'm working with an application that creates .mp2 audio files. I need to make sure the audio files are completely released by the application before moving the file to another directory. I have a ...
0
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1answer
128 views

Should I always call super in Java? [duplicate]

Anti-pattern considerations aside, should I always call super in Java when overriding methods, even when the method is empty? Take a look at the code below, this is an excerpt from AsyncTask and can ...
26
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5answers
3k views

Dynamic Code Evaluation in Java - Clever or Sloppy?

I am trying to create a flexible ACL framework in Java for my application. Many ACL frameworks are built on a whitelist of rules, where a rule is in the form of owner:action:resource. For example, ...
1
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2answers
238 views

A 'task' system which has an ending, to get ready for next task

I want to make a system, so that there are certain tasks. For example, let's talk about a game. I want to make it so there are 100+ tasks doing different things, but when the player's magic level is ...
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2answers
217 views

How to manage data flow between UI components?

I have been trying to use classes that implement ActionListener to respond to user input. I'm consistently noticing that for an action listener to communicate the event to other objects, it has to ...
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0answers
31 views

Spring Boot Hibernate and JSR 303 - response formatting

Sifting through forums I can't seem to stumble into an issue solution I've been haveing with Spring Boot + JPA and JSR303 bean validation. Simply put validation works but but when say ...
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0answers
48 views

I'm developing a tiny db software and how to integrate a db in my installer [on hold]

This may not be a good question but i want to create a database software and im using MSACCESS as my database using JDBC but i want to integrate a lightweight database to my software installer and i ...
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0answers
50 views

How to create methods at runtime for scripting purposes? [on hold]

!!! There's a TL;DR question at the bottom of this !!! I'm looking into writing a Java API that developers can implement that will allow users to write their own scripts that can interact with a ...
2
votes
1answer
256 views

DataMapper for a MMO game plugin to send packets

I am working on an plugin for some game-server. The information about the plugin is not really necessary. Few points you might find helpful to answer to this question: The server The server is ...
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votes
1answer
68 views

Creating multiple houses in Java? [on hold]

everyone! I created a program that would draw a house in Java, which is: import java.awt.*; import java.applet.*; // Program to draw a house public class House extends Applet { public void ...
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votes
0answers
82 views

Error: Code too big for 64k [on hold]

Im having a bit of an issue with a simple program I'm trying to build. Im using an IDE to code a program I wish to turn into an app in a few months. After 7500 lines of code I receive and error ...
1
vote
1answer
72 views

Non-fixed-size Fenwick Tree implementation

I'm planning to implement a non-fixed-size Fenwick tree. That is, a Fenwick tree that allows interleaving range queries with adding/removing elements. All implementations and samples I've seen so far ...
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2answers
80 views

Pattern for validating rules having different signatures

I have a class in charge of responding to an input event and maybe triggering another event. To decide, it has several rules to check. I'm trying to get away from a class looking like this: public ...
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0answers
4 views

Java j2ee JSTL cannot print a list of objetcs [migrated]

i'm currently working on a small Java J2E project. I want to print a list of objects in a *.jsp page, but there's an error i can't seem to get rid of. My .jsp page : <%@ page language="java" ...
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0answers
50 views

Generate random numbers in java…! [on hold]

I'm writing a code for a command line game in which I want to shuffle numbers randomly. i created 3 different functions. Each function generates a number different from other. and those 3 functions ...
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2answers
425 views

Is factory pattern a right pattern for the situation described here?

Is factory pattern a right pattern when we want to consolidate the related objects? Problem - In the Set-top box, I have a user-io, basically the interface to control the settop box - The user-io can ...
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0answers
14 views

Java Robot class highlighting text help [migrated]

I'm trying to write a program that copies text from TinyChat(https://tinychat.com) and copies it to the clip board. Eventually it will take everything said in chat and paste it in Skype. Every message ...
2
votes
2answers
104 views

When to use ANTLR and when to use a parsing library

I've always wanted to learn how to write a compiler - I've decided to use ANTLR, and am currently reading through the book (its very good by the way) I'm pretty new to this, so go easy, but the jist ...
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1answer
79 views

Architecture for my Java application [on hold]

I try to create small Java tools to help me at my work every now and then. Usually these do not have to be pretty and I find myself coding a single, sometimes massive, Java class. However, now my plan ...
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1answer
159 views

Debugging xml and annotations

By now, most web containers have an annotation variant of their xml configurations for Java EE. I'm guessing this is because it's better to keep things in Java where they can be managed, coded with ...
0
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1answer
406 views

Dynamic query in MySQL

I'm doing a J2EE web application with Struts2, MyBatis and a MySQL database, so what I want is to allow the user to be free to choose different parameters to perform a select to a table in the ...
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0answers
30 views

Reading from html page that needs cookies passed and form data

I am writing a program in java in order to practice tough coding problems and learn more. Program description The program reads first names from a text file one by one, then enters them into facebook ...
2
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1answer
60 views

Advantage of Declaring and Initializing Different Object types?

I am learning how to use java to program, and am just learning about abstract classes and how they are useful. Say I have a class which extends another abstract class, which has 2 methods, one of ...
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0answers
30 views

Is there a CMS that can be hosted online but is merely a backend for a desktop application? [closed]

All the CMS's I've used and read about are geared toward building websites. I need to make a desktop application that connects to and grabs data and settings from a CMS-backed online source. There ...
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1answer
219 views

Is this database design good? What JPA Entities should I create for this design?

I am trying my hands on JPA. For this I am thinking of using the example of a student admission process as shown in the diagram below. Is this design good ? Any suggestions for improvement are ...
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0answers
52 views

What are the different types of whitespace referred to by Perl? [migrated]

I am trying to find the Java equivalents of the Perl regular expressions not supported by Java. These are, as listed in the Java Documentation: \h A horizontal whitespace \H A non horizontal ...
1
vote
1answer
35 views

DataThread class that doesn't extend Thread, poor naming?

I created a DataThread class that doesn't extend a Thread, but has one as a member variable. Favor composition over inheritance, is a rule that I heard of, but I am thinking that the name of the ...
-2
votes
0answers
35 views

Get from object or use variable [closed]

Which one is better //somewhere here i have Test test = new Test(); object String name = "default"; if(test.getName() != null) name = test.getName(); or String name = "default"; String ...
0
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0answers
34 views

what is the relationship between CORBA, JMS and MDB?

In the context of my previous fuzzy question on microservices, please help me break down the terminology involved in these technologies: CORBA JMS MDB Utilizing JNDI, I believe it's possible to do ...
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votes
1answer
31 views

What's the best way to implement a real time show board to show results from concurrent result producers in Java?

I'm making a load test tool that launches multiple thread to simulate load on the target server. Each thread executes a predefined set of commands in the structure of TestSuite - TestCase- TestStep ...
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2answers
59 views

How is the best way to work with step by step documentation to software maintenance [closed]

I'm working on a web project in java and I have a problem with the documentation we are making. The goal is to has step by step how to do some basic stuff for system maintenance, like add fields to a ...
-2
votes
0answers
41 views

Java Web Framework for Functional Reactive Programming [closed]

Given Java intricate relationship with web applications it appears to have shaped the design applied to how developers create web based applications. From Java 1 through Java 7 from around 1999 the ...
8
votes
6answers
867 views

Static functions vs classes

Let's say that I want to build some utility functions to do some basic maths with the BigDecimals, for example I want to have a function that computes the average of a List<BigDecimal>. What is ...
2
votes
0answers
115 views

Testing a method that reads from standard input and outputs to standard output [migrated]

I have a method which reads lines from standard input and outputs them to standard output. In a JUnit test, how can I have it send standard input to the method and how can it make assertions about the ...
4
votes
1answer
182 views

Is it possible to use the Android layout system in a desktop java application?

I am lazy, thus, if possible, I would like to only have to design and program a UI once. If I want to create an App for Android and as a basic Java desktop application, is there a way to reuse the UI ...
-3
votes
0answers
30 views

Multiple URLmapping using annotation not working in servlets [closed]

I am using an annotation like this : @WebServlet("/Document/*") and trying to redirect using sendRedirect response.sendRedirect("Document/manpreet121FECF23A-D4D2-E411-BEC4-FCDD55FFFFFF"); I get ...
-3
votes
0answers
97 views

How much programming should I know at the age of 17? [closed]

I love programming, I will study computer science in college, I am a junior in high school right now. I want to work for big IT companies such as Facebook, Google, Dropbox, Apple.. I want to have a ...
1
vote
3answers
97 views

What is the best way to store and use an application level runtime parameter? [closed]

I have to design a java console application which accepts a runtime parameter as an argument to the main method. The application will be eventually used by multiple scripts. I would prefer to avoid ...
-2
votes
0answers
39 views

Printing out 2d arrays which contain null values (java)? [closed]

I'm very new to Java and was wondering if there was a way to print out a 2d array which contains null values, but instead of writing null it just prints a space. My code so far is: for(int i=0; ...
-3
votes
0answers
24 views

Setting up Struts 1.x in eclipse EE luna [closed]

I need to set up Struts 1.x in Eclipse. I looked into a previous post in the link below . In one the the answers the link given is dead. The website where that tut is does not work ...
5
votes
1answer
180 views

Sometimes, “programming to interfaces” introduces possible (and avoidable) runtime exceptions?

Please consider the com.google.common.collect.ImmutableMap Programming to its interface, Map , creates a bug that could blow-up in the runtime as such: Map<String, Integer> myMap = ...
2
votes
2answers
90 views

Immutable vs Read-only vs Unmodifiable naming difference

So, I've looked at some similar questions asked here in regards to how these three should be used in naming. Usually, the answer is something along the lines of "it's conventional" and "just be ...
-2
votes
0answers
55 views

interoperability java and c++ [duplicate]

i want to write a program in two different languages java and c++ that needs a dynamic and interactive communication between its c++ component and java component.i know there is jni and jna for ...
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0answers
75 views

How do I translate my source file to Java bytecode? [closed]

I'm creating a new programming with JavaCC which is the parser. I want the parsed data to be translated to Java bytecode and compiled to Class file which later will be executed by JVM Edit: I'm a ...
3
votes
5answers
432 views

Why is the hashCode method usage of HashSet not specified in the API?

I was trying to debug my code which uses a HashSet and searching through the SO, I found out that I needed to override the hashCode method as well. The strange part is, checking the related API, I did ...
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votes
0answers
82 views

Does C# meet my all of my needs? [closed]

TL;DR: Are there any serious issues with using C# over Java for mobile dev and would I be more likely to find jobs in game development with C++ or C#? -- At the moment I'm familiar with HTML, CSS, ...