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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4
votes
1answer
123 views

Is it better not to .close() inside API method body when passed a Reader or InputStream?

There are plenty of similar questions that have been answered. Example here. However, they all have both the Reader and the InputStream within the same scope or method body, and so suggest to close ...
0
votes
0answers
39 views

WCF security with Java client

I'm about to develop a WCF service which is going to be called by an external Java client. I've developed a couple of services before but they were called internally, so security is now a concern. ...
1
vote
1answer
122 views

TreeItem containing non-String object displaying strange text

Hello StackExchange community! This is my first post and appreciate any help anyone can offer. I'm new to Java, and I'm sure this issue is simply due to my misunderstanding of the fundamentals. I ...
3
votes
2answers
324 views

Is turning a method into a class to use it across many classes bad practice? [closed]

Let's say I have a sort method inside of my class and another class that has no relationship with that class needs the same method. Instead of writing that method twice and breaking the do not repeat ...
3
votes
1answer
104 views

How to access environment-specific configuration in an enterprise application?

My application is a generic enterprise application which can be deployed on any application server running on any OS. I don't know how/where to configure my application, except for the database ...
-2
votes
3answers
166 views

What is the most elemental workflow for TDD?

Gradle is such an interesting build tool that it prompted me to look at Spock and JUnit -- which I've never done before. What is the basic workflow with TDD? My approach has been to do frequent ...
0
votes
2answers
179 views

Whether to use enum vs map vs config file?

I have ~30 resources each having ~10 attributes. I want to store some information about each attribute. Ex: its multiplicity, it RW (Read/Write), RO (Read only), longName, shortname. So I was ...
5
votes
9answers
377 views

Why is using an optional preferential to null-checking the variable?

Take the two code examples: if(optional.isPresent()) { //do your thing } if(variable != null) { //do your thing } As far as I can tell the most obvious difference is that the Optional ...
1
vote
1answer
59 views

Service/component based application in Java

I have a Java project whose architecture is quite component-oriented, and I am wondering if this is a common way to organize code which rules/patterns are used, if there is a name for this coding ...
1
vote
0answers
94 views

Handling multiple rest api versions within Android Java client

Actual architecture I have an app where a model is attached to every activity. The model ask a repository for information that can come from server or local db depending on many factors. When it asks ...
-1
votes
1answer
237 views

In which cases and examples String in Java is not immutable? [duplicate]

If Strings are immutable in Java, why is the output of this code 2GB, instead of 1GB? class Laptop { String memory = "1GB"; } class Workshop { public static void main(String args[]) { ...
3
votes
1answer
100 views

How to paginate local and remote data?

My team is currently facing a problem that we don't know how to tackle. Some technical details: we use Java 8, Hibernate, Spring, MySQL, and AngularJS for the front-end. We need to do pagination on ...
3
votes
4answers
243 views

In which layer should validation be located?

I'm creating a Rest API using Spring Boot and I am using Hibernate Validation to validate request inputs. But I also need other kinds of validation, for example when update data needs to checked, if ...
6
votes
2answers
248 views

Is it an antipattern to use peek() to modify a stream element?

Suppose I have a stream of Things and I want to "enrich" them mid stream, I can use peek() to do this, eg: streamOfThings.peek(this::thingMutator).forEach(this::someConsumer); Assume that mutating ...
2
votes
1answer
207 views

Communicating with third party API

I am working on an App which basically communicate with a third party API, it has no back-end. The front-end will be a SPA. Here is the overall scenario: The external API needs current user's Id to ...
0
votes
0answers
75 views

Options for implementing database and programming logic for statistics application?

I am implementing a statistics driven web application. The statistics relate to sporting events. Right now I have a postgresql database with a table that holds a row for each match. This is a ...
1
vote
1answer
100 views

Compiler design prevent register override

I'm trying to write a compiler for a self-designed CPU with accompanying instruction set. The CPU has 3 registers, 2 input registers (B and C) and one output register (D). When for example an ADD ...
1
vote
1answer
148 views

Is stack allocation in Java implementation dependent?

I've looked through the different threads, and there are a lot of conflicting information out there. The most useful article I found was this: Java theory and practice: Urban performance legends, ...
18
votes
3answers
638 views

What are the reasons for why a Java/Linux stack fails to be “real time”?

I have often heard developers mention that Java can't "do Real Time", meaning a Java app running on Linux cannot meet the requirements of a deterministic real-time system, such as something running on ...
0
votes
2answers
98 views

Design pattern to holds API exchanges? [closed]

I'm developing a simple application that crawls in web pages to obtain some information. For this I used and tested some libraries, like crawler4j, jsoup, jaunt and htmlunit. I exchanged several ...
0
votes
0answers
104 views

Java Multi-threading

I was solving this question in Java where the user enters a partitioned array. The computer then determines what all elements from that array can be used as pivots. (Pivots are the same pivots that ...
7
votes
2answers
319 views

Is using this complex data structure bad practice?

Right now in my current company I must "parse" a csv and extract some data out of it (in the sense of data mining). I surprised myself by defining the following data structure (Java 8): static ...
3
votes
1answer
189 views

How is this Java Keystore cert still valid?

I maintain an old Java app that deploys to Tomcat and which uses SSL (and hence a keystore). It is important to note that this app will not even start up if the SSL cert is bad/expired/invalid! Every ...
1
vote
2answers
110 views

Does an interface including several methods that return instances of Object make sense?

I am in the process of writing my first true API. In the process, I am defining an interface for mapping complex data structures onto other complex data structures. At the moment, the interface ...
0
votes
1answer
46 views

Concurrent and atomic updates to multiple properties/variable of an object

I have a class with multiple setters and want to make atomic updates to multiple properties/variables. As far as I can see there are three methods that could work: Call all setters in synchronized ...
0
votes
2answers
133 views

Moving Java static variables into XML

I've been working on a small Java project by myself for a department that does not do a lot of software development but mostly database stuff. I showed my boss the code I've been writing and he saw ...
0
votes
0answers
45 views

Libgdx texture and sound disposing

I'm writing a game and in the game, I use an asset manager that is in a singleton class, which holds my textures and sounds. If I create several enemies (lets say 4) which call upon my asset manager, ...
95
votes
13answers
15k views

Should we avoid language features that C++ has but Java doesn't to increase maintainability?

Suppose I am limited to use C++ by the environment in the project. Is it good to prevent the use of some language features that C++ has but Java doesn't have (e.g.: multiple inheritance, operator ...
2
votes
1answer
124 views

Is IntentService an implementation of Command Pattern?

According to Wikipedia: In object-oriented programming, the command pattern is a behavioral design pattern in which an object is used to encapsulate all information needed to perform an action or ...
2
votes
2answers
179 views

For what reasons Java and C# initialize static data on demand?

I am reading "The Go Programming Language" right now and I have read package initialization chapter which tells (or I read it wrong) that Go uses eagerly initialization. So in time we saw say C++ ...
1
vote
3answers
253 views

Java need to call many methods systematically

I have a group of methods that is going to be very large. I need to be able to call methods systematically from a large group, in two different ways. The methods create a new item object with ...
0
votes
1answer
65 views

TDD with a half baked Java EE application

I am a second year Computer Science student currently on a placement and I am currently developing a Java EE application that collects meta data from several sources and then visualises the data. This ...
1
vote
1answer
112 views

Intelligent builder pattern - different parameters depending on type - generics?

Lets say we have the famous Joshua Bloch Nutrition Builder and we want to change it so it be a bit like dynamic builder which restricts visibility of setters and propably uses generics : public ...
3
votes
1answer
160 views

what happens at Java interpreter level when IncompatibleClassChangeError is thrown?

I am a noob at JVM internals. Can someone explain what happens at Java interpreter level when IncompatibleClassChangeError is thrown? I am facing an issue similar to the one described here: ...
2
votes
1answer
54 views

A way to update a list an Android application displays

I just started working on an Android app that should display posts from my site and then a three-column list of some products. The three columns on the list contain the product names, a short ...
6
votes
5answers
529 views

How to design a complex REST API considering DB performance?

I've been following some tutorials on how to design REST APIs, but I still have some big questions marks. All these tutorials show resources with relatively simple hierarchies, and I would like to ...
0
votes
2answers
396 views

Why use XML in Android?

From what I understand, isn't XML used for layouts and to setup how an activity looks? My book says that XML files are converted into Java code but then, why not just write everything in Java?
2
votes
2answers
188 views

Where is the class itself stored at runtime to be used as a reference

In C# or Java we find that the objects are stored on heap and their reference vars are stored on stack. But at run time where is the class definition stored to be used as a template for creating ...
0
votes
1answer
112 views

What is the difference between a 3rd party lib and a plugin

What is the difference between a 3rd party lib and a plugin? How do I choose what should be pushed to these repos? plugins-release-local = Your and 3rd party plugins (releases) ...
2
votes
1answer
142 views

Using prototype/non-Spring managed beans in Spring Web application

I have been working on few web applications/REST web services recently (Spring IoC/MVC/Data JPA etc) and they usually follow the same pattern: Controller classes --> Service classes (which have number ...
1
vote
2answers
229 views

How to deal with Classes having the same name (different packages)

My R&D team have Java packages containing classes with the same name. For instance: com.myapp.model Device ... com.myapp.data Device ... We had a discussion, the names conflict when both ...
9
votes
1answer
322 views

Enum with a lot of boolean properties

I'm currently working on a webapp where we often need to condition some server logic based on the page that is going to be returned to the user. Each page is given a 4-letter page code, and these ...
-1
votes
1answer
104 views

Problem on recursion

void function(int x){ if(x<=0) return; function(x--); } This is a recursion function which is called with the value of x = 20. The Recursive call will take place in this way ...
1
vote
3answers
230 views

Why would I need `equals` if I have already `hashcode`?

I got a question about why we need equals if we have hashcode. My first attempt was the answer because collision. But we corrected starting point with the assumption that we have not many objects so ...
1
vote
0answers
32 views

How can I test for performance issues in a specific piece of code? [duplicate]

I've inherited a problem from a programmer that isn't with our group anymore - a piece of our application suffers from performance issues under a particular set of circumstances. I can replicate ...
3
votes
3answers
152 views

What is “Split Data Model”, mentioned in the book “Java Concurrency In Practice”?

I'm learning Java multithreading programming by the book "Java Concurrency In Practice". In chapter 9.4.2 Split Data Model, I read this: From the perspective of the GUI, the Swing table model ...
1
vote
0answers
26 views

Correlating Search Classifiers in a Database Scan for Sensitive Information

Problem Description I am working on an enterprise data discovery project that is designed to scan databases for sensitive information. The basic search unit is called a classifier and covers things ...
4
votes
1answer
135 views

Name-Based Sorting Algorithms For Maximized Common Letters

I am attempting to write a program for a competition (we're allowed to consult Stack Exchange, as long as I'm not given physical code) that takes in a list of 5000 people's names (distributed fairly ...
1
vote
2answers
75 views

Should a client check for persisted item existence before modifying it?

I'm developing a MVC Web application with a REST interface. The REST controller performs actions on persisted items through a service class, which translates exceptions coming from the persistence ...
0
votes
1answer
267 views

Why is Eclipse platform dependent?

When Eclipse is written in Java and Java is platform independent, why does Eclipse offer different versions according to platforms? I assume it should be write once, use anywhere code.