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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0
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2answers
28 views

Guava Multimap merging consecutive items with same key

I have been playing around with Guava Multimaps and I ran into an issue with tracking when an user is damaged (more the way it's displayed, really) Let's say I have a Multimap<User, Hit> and ...
-1
votes
0answers
29 views

Dynamic diploma generation [on hold]

I'am working on online training site. When user finished the course I would like to generate downloadable diploma for him. He could print it and hang it on the wall. It should be graphically ...
0
votes
0answers
22 views

Should fragments register directly to an event bus or should only activites do so?

Please correct me if I'm wrong about any of the following. I understand that if a fragment wants to make a network call it tells it's activity then the activity makes the call and returns the answer ...
-1
votes
1answer
62 views

Using sessions with Jersey in a REST API

I am starting to develop a REST API with Jersey to retrieve a schedule for a given sport tournament. The client sends a JSON containing a tournament with its different categories, domain, definitions ...
0
votes
1answer
33 views

Building an API with one central connection object to an external device

I want to build an API (Java) that heavily relies on a connection object to a data server that manages a connection to a real device. All i have is a DeviceConnection object. Currently i have a big ...
-2
votes
1answer
66 views

Duplicate code to avoid performance decrease due to function calls? [on hold]

I have a simple list in Java that I need to search using one of two methods. The first method simply returns the position in the list of the first matching element. The second filters out any elements ...
-5
votes
0answers
35 views

Add simple GUI to Java program [on hold]

I have Java program with two classes "server & client" (packet programming), and I need to add simple GUI for this program. Appreciate if anyone can help me .. Client.java import ...
-1
votes
1answer
51 views

How do you deal with NULL values while creating jsonObject?

I am learning java and jsr-353. My question is quite forward. Having the method below: public JsonObject createJsonObject() { return Json.createObjectBuilder() .add("address", ...
1
vote
1answer
46 views

Parameter objects place holder?

If a method has too many parameters, the suggestion is to convert them into a parameter object. Where to place such parameter objects? in domain/entity classes package? or if I have a separate package ...
-2
votes
1answer
49 views

Java/OOP-Book for functional programmer [on hold]

I'm a functional programmer (mostly Haskell) and have some experience with OOP - I know how inheritance, overloading, ... work, also I have experience with low-level procedural languages like C. I'm ...
0
votes
0answers
18 views

Concept analysis: using a Java ServerSocket to let an Android phone and server communicate?

I have an idea for an application that will not be published to the public Play Store. My friends will need to be able to log in from their Android phone to view certain data that cannot be viewed by ...
-2
votes
3answers
80 views

Java Ellipses Signature for Multiple Parmeters

Firstly, I am studying function with new type of signature and body, and in this code, I want to know, what type of object is values? It doesn't appear to be an array of strings based on my ...
4
votes
4answers
195 views

JSON API or Plain JSON

There is a debate in my company on whether we should use the JSON API specification or stick to plain JSON for developing APIs that will be consumed by mobile apps, mainly iOS and Android. One ...
-2
votes
0answers
71 views

How can I prepare myself for programming in PhD research? [on hold]

My background is in Computer Science but I'm not practising programming since a long time so I only remember how to decalre a variable and assign it a value (in Java). In 6 months time I'm going to ...
4
votes
1answer
119 views
+50

Should use case/interactor `execute` method accept parameters

In most examples of clean architecture (Android projects mostly, though) I've noticed that the use-case/interactor classes (units that encapsulate a feature) often share base class/interface, like ...
0
votes
0answers
41 views

Embedding custom business logic using Javascript in Java application

We have an application where the front-end is completely rendered dynamically. The web page is stored as JSON in the database. A simple JSON to display input field with a label is as follows: { ...
-5
votes
0answers
38 views

Twitter login through javascript [closed]

I want to write only JavaScript code for twitter login and fetch logged user information like screen name , user link URL , user location etc.
0
votes
0answers
27 views

Inheritance and Parcels

In Android development, we have Parcelable interface. Since I wish to build Data Models that will run on multiple apps and services (not just Android), I would like to add two jar libs that will share ...
1
vote
1answer
69 views

Is this indexed approach to java rts game development valid and how can I improve it?

I have class GameState laid out to basically hold an Array of Players, an Array of StarSystems, and a few other fields that need to persist from save to save. Each GameObject keeps track of its own ...
-1
votes
0answers
36 views

J-Boss, Jackson, RESTEasy: what do these RESTful tools do?

I'm sure that question seems very asinine. I understand the purpose of these sorts of tools is to… Remove an unnecessary outer layer of Java servlet code that can be replaced by annotations. Handle ...
-3
votes
0answers
68 views

Biggest palindromic number which is a product of two 3 digit numbers [closed]

I've got to find the biggest palindromic number which is a product of two 3 digit numbers. I wrote a program for it in Java but something is going wrong. Here is the program I've written. public ...
1
vote
2answers
75 views

Passing and returning domain object in create method

We have this bean with two properties: ContainerImage + name (final, not null) + id (null) Then there is this method: ContainerImage create(ContainerImage containerImage); It receives ...
0
votes
1answer
83 views

How to setup multiple queries with slight differences

I'm writing a page that will show the user statistical data about some of our products. Basically the user can get results between a specific time frame, and also add on other data to lookup by. For ...
-1
votes
0answers
85 views

Packaging a HTML,JS,CSS project within an application for security.

We have a project which is designed with html,css and JS. For demonstration purposes, we have integrated the project inside a JavaFX app in the webkit browser and from there we are just loading the ...
0
votes
3answers
158 views

A very basic question about whether I should check for null and throw NPE? [duplicate]

Consider the below method- public void operationOnList(List<String> list) { list.add(1); } It is obvious that if l is null this method will throw a NullPointerException. My question is ...
1
vote
1answer
76 views

When we need to serialize an exception

I have been developing in Java since 8 months, and I didn't face a case where I went to serialize an exception, I'm asking because I saw the serialVersionUID and how Eclipse advise to add it ...
2
votes
2answers
127 views

Placing preconditions in the right place

I am trying to figure out the best way to define the responsibility of checking preconditions. Let's consider the following case: we have an Event class representing a sports event and a Matchup ...
2
votes
1answer
119 views

What are the limitations of Java exception approach to errors?

Please ignore performance issues, I am interesting in data flow, safety, modelling, reasoning. I wonder what are the limitations of exception approach to error reporting implemented like in Java ...
2
votes
1answer
129 views

Choice of variable names and types in graph algorithm

I am learning algorithms and data structures from this awesome resource Algorithms. Rather than doing dry reading I am trying to re-write all the code myself so that I can learn coding as well as ...
2
votes
5answers
310 views

Why do I need to declare virtual functions as such?

Example: We have a base class Base and three subclasses which all implement their own version of doSomething(). In an intermediate function f(Base b), we want to call the relevant version of ...
4
votes
3answers
112 views

Passing a private member collection to another class

Suppose I have a Map which is a private member variable of my class A. In the same class I create an instance of class B, call it objB, by passing the map to B's constructor. Obviously this is ...
0
votes
2answers
40 views

Best Communication strategy for monitoring dashboard

I have a requirement where I need to display certain stats on Admin Dashboard in my web application (Angular+Java). These stats (transnational data) are being generated on different servers (connected ...
2
votes
2answers
88 views

C++ vs Java: Pointing to Objects

In Java: private State current_state; As "State" is a superclass, I can then assign subclass objects to current_state, effectively making current_state point to a different object: current_state = ...
0
votes
0answers
32 views

Better way to model parallel implementations of specialised collection-like types

I am working with some wrappers for selection widgets on the web (in Selenium). They each have one "parent" type that represent the widget and another type for the options. Two interfaces are created ...
3
votes
2answers
83 views

Creating Instances from same SuperClass Object

I have 3 subclasses (LowState, MediumState, HighState) which derive from the same superclass (State). Within the superclass, State, I have declared several variables which need to be accessed and ...
-3
votes
0answers
27 views

Certificate Subject Name Filtering - Glassfish [closed]

We have an issue with our glassfish server which should only be trusting certificates with an appropriate Distinguished Name, Subject values - corresponding to certs added to the trust store. ...
0
votes
2answers
111 views

Could Java XYZ implement (limited) Operator Overloading without breaking backwards compatibility?

Recently, I've been learning a bit more of C++ and the dangers and uses of operator overloading, and the readability boost it provides to arithmetic types (like Complex numbers). A while ago, I was ...
1
vote
3answers
232 views

How to store many global variables?

I have around 30 not-changing "objects" (the amount of them is final, no more can be added or removed). Each object has an id as well as some booleans describing what the object is and what it isn't. ...
0
votes
3answers
85 views

Cyclic dependency in this project design

I have 2 modules (containing multiple classes). Let's call them Module A and Module B. Module B has a dependency on Module A: Module B -> Module A. Now, I have created an utility class C, which A ...
5
votes
1answer
62 views

Discoverable default implementation of an interface

I have a couple of simple classes that implement the Null Object pattern. To illustrate the hierarchy, let's define a Config interface with two classes implementing it ConfigItem and MissingConfig, ...
2
votes
1answer
82 views

Should I return Iterable or Enumeration in Java

In order to achieve better immutability, should my API return java.lang.Iterable<T> or java.util.Enumeration<E>? Since Iterable has a remove() method, one could say Enumeration is the ...
0
votes
1answer
62 views

Naming conventions clashes when using postgres with jpa [duplicate]

I am using a jpa implementation which basically works on annotations with postgres database The postgres standards for naming field names is snake_case where as it is camelCase in java is there any ...
2
votes
4answers
264 views

Is it strange for a Builder object to have getter methods?

I have a fairly complex immutable data type that I'm using a builder object to instantiate. Currently, I have a setup where I parse a file, setting various fields in my builder, and then build the ...
1
vote
1answer
21 views

Redesigning schedule value hierarchy

I have a couple of schedule value classes that represent the value a schedule holds for a specific slot. First, there's the ScheduleValue class for schedules with two dimensions, where the first one ...
2
votes
2answers
100 views

Image resizing client side vs server side

When uploading a lot of images to a server, to minimize the space taken by the images, is it better to resize the images before sending to the server or upon receiving them? It seems to me that ...
5
votes
6answers
377 views

Dependency injection: should I use a framework?

I have recently worked on a Python project where we did dependency injection heavily (because we must in order for the app to be testable), but we didn't use any framework. At times it was a little ...
4
votes
3answers
206 views

Enums and single responsibility principle (SRP)

I have been experimenting lately with enums, and I found out that in Java they can do much more than simply representing a fixed set of constants. Now, I am thinking about creating a new enum for my ...
9
votes
3answers
218 views

Breaking API changes: how can I make the transition easy for library users?

In the past, I used the standard way of adding @Deprecated annotations to API methods which will be removed in a later version. Now I am preparing a major version for a library, with many API parts ...
1
vote
3answers
97 views

Xml Messages: One Type to Rule Them All?

My job involves a project that has a lot of different pieces that all need to communicate via XML messages. There are two schools of thought on how these messages should be organized. In reality ...
49
votes
10answers
11k views

Why would the 'final' keyword ever be useful?

It seems Java has had the power to declare classes not-derivable for ages, and now C++ has it too. However, in the light of the Open/Close principle in SOLID, why would that be useful? To me, the ...