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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2answers
92 views

Why am I getting field visibility warnings in Sonar?

Some static analysis tools flag non-private fields with Variable '[nameHere]' must be private and have accessor methods. Sonar consistently presents such warnings and wants to change all ...
-1
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3answers
122 views

Java and C++ connection? [closed]

Quick question about them. Are they semantic kind of way related? I am learning C++ and I want to start java too. Can I get confused when learning the two languages?
0
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2answers
179 views

Working with two different database types for one application [duplicate]

Software: Java J2EE Application hosted on Tomcat Server. UPDATE The current software is JAVA Web application containing just JSP and Servlets no frameworks or anything. Simple JSP and ...
2
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1answer
55 views

Use of validators for simple validations

I've been working in Liferay code, and I've come across this construct a few times: List<?> list; ... if (Validator.isNotNull(list)) { //do stuff }} The source code for Validator.java ...
3
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2answers
133 views

Enums in java switch-statements and completeness

I feel like I should be able to find an answer to this, but it turns out to be harder to search than expected... so: In C#, when we do something like: enum MyEnumClass { A, B }; static String ...
3
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3answers
363 views

have we come full circle with microservices, back to very old school approaches?

In terms of software architecture and design, how do microservices "stack up" (pun intended) against middleware? I'm coming from Java, and it seems like as you move away from straight REST as an API, ...
-4
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1answer
82 views

Hacking software development in Java [closed]

Is there a good tutorial about hacking in Java? Is it even possible? And if yes where do i start? I am programming a website with database in hibernate using Java, Struts 2, TomCat. And wondering how ...
35
votes
9answers
12k views

Why do schools teach arrays over List? [closed]

Most of the assignments in my school for the initial programming classes required me to use arrays. I work full time now, and I never used an array for any project that I have worked on. Even in the ...
4
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4answers
275 views

Why use an enum to determine node type in a parse tree?

The Sun Compiler Tree API uses an interface called Tree as the parent of all the different kinds of parse tree nodes (assignments, if-statements, class declarations, etc.). A part of this interface is ...
5
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2answers
345 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 ...
1
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2answers
207 views

Is public final completely (not) ok in constant enum fields?

When I make enums that hold some fields, like my Settings enum, I like to make them public final to avoid lots of ( and ) keystrokes: public enum Settings { SETTING_TEST("bool_setting1", false), ...
3
votes
4answers
667 views

Robot in a grid

This was recently asked to someone I know. A robot has to move in a grid which is in the form of a matrix. It can go to A(i,j)--> A(i+j,j) (Down) A(i,j)--> A(i,i+j) (Right) ...
0
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1answer
158 views

Program to look at the first say 5 characters of a word and return a string if that string is actually the first 5 characters of a word?

For example, say I have a string and it has the letters: RDNAL This is not an actual English word or it doesn't start an actual english word, so the program would skip this string and would avoid ...
0
votes
5answers
387 views

Interview Question - Adding Method to interface that has been implemented by thousands of class [closed]

There is scenario where I have Interface X, which has been implemented with my thousands of classes. Now I want to add new method in that Interface X. So how to make the changes in minimal way to ...
-1
votes
3answers
122 views

Complex Number help

OK so I have a programming assignment and I need to create a class that represents Complex Numbers (good so far), add them to a list(good so far), and then output whether each individual number is ...
12
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0answers
231 views

Haskell build and artifact environment similar to Maven

I used to be a Java developer for a long time, but recently, I joined a Haskell team. In the java world, if you have a large project, with several teams working on it, a common approach is to use an ...
2
votes
3answers
443 views

Can a Java Boolean be used for ternary (3-state) logic?

I'm trying to make a basic cache of a boolean value, and I did it like such: private Boolean _valueCache = null; private boolean getValue() { try { if (_valueCache == null) { // if cache ...
0
votes
2answers
106 views

What naming convention should you use for data objects solely meant for parameters

This is my pseudocode for DAL: CusOrderDTO GetCustomerOrder(DateTime OrderDate, string customerCode) CusOrderDTO orderSet = new CusOrderDTO() * query data from database, populate CusOrderDTO ...
0
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1answer
99 views

Is there are any common pattern/practice to handle exception list (Java)? [closed]

Suppose I've got a sophisticated parser for something. And a I don't want Throw Early/Fail-Fast strategy. If I've got multiple problems, i want to have list of exceptions in my log file because I want ...
0
votes
1answer
101 views

Java Socket or SocketChannel

I am designing a server for a remote file store in Java and trying to decide whether to use asynchronous java.nio.SocketChannels or the older blocking model with Sockets. What kind of factors should I ...
-3
votes
1answer
117 views

Java Start JNLP without paying to certificate authority?

I've noted that now it is difficult to run Java Web start files (JNLP) by Oracle for Java8, without a proper certificate, due to "security reason".It is breaking thousands of applications across the ...
0
votes
1answer
158 views

Injectable, Poppable Stack

Background A project involves converting a relational expression map (rxm) to an XML/SQL statement. The map resembles: root > people, # "root" keyword starts the document ...
2
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1answer
48 views

Can tools.jar from OpenJDK can be installed in public repository

Is it legal to install tools.jar from OpenJDK in public maven repository? I found at least three topics on the Internet which conclusion was that such action is forbidden for jar provided by Oracle, ...
4
votes
1answer
152 views

Should I implement the consumer/producer pattern in my java video app, and if yes, how?

I built a small video frame analysis app with desktop Java 8. On each frame, I extract data (5 doubles now, but could expand to a 1920x1080x3 OpenCV Mat in the future). I would like to store this data ...
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votes
1answer
42 views

Create a main method to run the below code [closed]

I'm learning Java. I wonder how to run the below code? public class Test01{ public interface Printable{ public void print(); } public class PrintRectangle implements Printable{ public void ...
1
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1answer
146 views

Hypothetical : What restrictions will I need to add to Java so that I can remove its GC? [closed]

This is a hypothetical, yet very technically precise question I'm trying to ask all the compiler/static analysis programmers. I'm trying to understand the extent of prohibitive features I would need ...
2
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4answers
113 views

Single method with many parameters vs many methods that must be called in order

I have some raw data I need to do many things to (shift it, rotate it, scale it along certain axis, rotate it to a final position) and I am not sure what the best way to do this to maintain code ...
4
votes
4answers
265 views

Styleguide when coding in a static language [duplicate]

I am currently a junior engineer and keen on learning best practices and expanding my experience. My question concerns any static programming language such as Java, C#, C++ etc. When I am writing ...
1
vote
2answers
109 views

MVC like design with interfaces: How to handle basic objects?

I have an (android) application and decided that the presentation layer will get data only through strict interfaces from the controller. I am at the point where some basic objects need to be passed ...
1
vote
0answers
198 views

Java write to text file from multiple threads

I have a thread which read and insert new lines in same file. I must synchronized that file so that no other thread is not accessing the file at the same time. Here is how i will synchronize a file ...
15
votes
3answers
1k views

Which version of Java should I use for a desktop application to reach the most users? [closed]

Am I correct to assume that most end users are using an older version than Java 8? Since I do not want to force people to upgrade in order to use my application, should I plan it to use Java 7 or even ...
0
votes
1answer
65 views

Lock object in base class: private or protected? [closed]

I have a base class that contains some lists, queues, and other fields which determine its state. In the base class I only access these fields within a protected lock object since there could be ...
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votes
3answers
167 views

How to design a solution that needs dynamism using Inheritance [closed]

I have below code/classes/interfaces: An Interface: public interface Animal<A extends Animal<A>>{ void fight(A otherAnimal); } 2.Tiger class which is implementing Animal ...
0
votes
1answer
56 views

How is ServletContext created?

When the webapp gets loaded the container will create the ServletContext. There is only one ServletContext per webapp per JVM. The ServletContext object is contained within the ServletConfig ...
2
votes
2answers
189 views

Problems with OO design for application with pluggable components

I'm trying to refactor an ugly code and make it easly extendable in the future. The application should be nothing else but a series of components that have input(s) and output(s). The components ...
0
votes
1answer
73 views

Return values and exceptions [closed]

I wrote simple function that returns a string depending on which condition is TRUE. Here is my code: private String getMyString() { if(!mStrigMember.isEmpty()) { return mStrigMember; ...
1
vote
4answers
180 views

What is the proper way for these methods to function?

How can I properly design what a method or function should do? To clarify the question I am going to use an example from a simple (non GUI) hangman game I created. The design is simple, it has a ...
0
votes
0answers
71 views

Is there any necessity to pass a variable parameter to a method while the variable declared global? [duplicate]

I am writing a class in java of Monte-Carlo algorithm. Here is the written code - public class MonteCarlo { int[][] matrix; public void monteCarlo(List<Node> nodeList) { matrix ...
2
votes
5answers
225 views

Implement multiple separate interfaces or interface hierarchy

I've been refactoring one of my projects recently and ran into a decision I have to make. I have several interfaces: Entity: Something in the game world Actor: An Entity that can perform actions ...
0
votes
3answers
215 views

Why are there no java compiler alternatives to allow new functionality? [closed]

For example, a new java compiler could allow for some breaking backwards compatibility to allow for things like overloading on generic types like: void foo(List<String> arr); void ...
11
votes
2answers
636 views

Java has the JVM, what does C have?

I know that C has a compiler but what determines execution performance? For example in an if else block, what if the code just had all ifs instead of if elses, what determines that all the ifs will ...
2
votes
2answers
218 views

When to use a SortedMap interface?

The rule in programming is to use the most general interface possible. But the difference between Map and SortedMap is more subtle. They compile to the same bytecode [I think] No additional safety ...
1
vote
2answers
118 views

Caveats of using String.hashCode() on a switch on java < 1.7

There are several cases when I want to switch over a String input. I decided for implementing something like: public Object doStuff(String param) { switch (param.hashCode()) { case 1234546: ...
1
vote
2answers
162 views

My value checker function needs to return both a boolean and a message

I have a value checking function, something much like a credit card number checking function, that is passed in a string, and needs to check that the value is of the right format. If it's the right ...
9
votes
7answers
2k views

Does Oracle reap economic benefits by maintaining Java? [closed]

It occurred to me that many programming languages such as Python and Javascript are maintained by non-profit foundations. I can see why a foundation would update a free programming language- in order ...
1
vote
2answers
109 views

Adding Logging to a pre-existing Program

I have a game that I have been writing in java as a hobby for a number of years. I have very sparse logging, just some simple output when something goes really wrong. It's about 25,000 lines of code. ...
4
votes
2answers
229 views

Exception versus return code in DAO pattern

After reading a lot about the abusive use of exceptions in Java and how you should let an exception bubble up through the different layers of an application, I've come to a point where I don't know ...
2
votes
1answer
89 views

Transactions and subresources with JAX-RS

I'm porting an existing application RESTful API to a Java web framework -- I don't actually care which -- but it's proving hard to get the basics right. The core of the problem appears to be getting ...
7
votes
2answers
263 views

Retry design for high volume

I have a Java system using ActiveMQ for messaging. And the system processes about 400 to 600 transactions a second and we have no issue when everything is running smoothly. The system also got to send ...
0
votes
1answer
78 views

Pattern for separating UI code from logic in Wicket

I'm using Apache Wicket for developing web apps, I have developed a few for the last year and it has been great; today I was looking at a few pages and most of them look like this: public class ...