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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Java REST API validation

I have a REST API with a service layer behind it. I am using Spring (Core and Data, as well as Security) and Jersey for the REST endpoints. The project has very sophisticated business logic, thus I ...
-3
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0answers
17 views

Which software could you recomend for do a Artificial Inteligence

I'm new in this page. wel.. I want to program a Artificial Inteligence, but I dont know what software use and what do I have to learn for do it. Can u help me? I was programing on java, php, sql and ...
-3
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0answers
35 views

Efficient programming: Java [on hold]

I have just started to learn Java, this is my first programming language. I would like focus on efficiency from the beginning to be able to write fast programs. What is the basic "know-how" related ...
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2answers
144 views

Java: using final keyword only on method parameters that expect immutable objects?

I came across the interesting topic about final method parameters and that they essentially don't provide much advantages. I wondered if it would be sensible to mark only those method parameters as ...
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35 views

Unable to hit on java controller [on hold]

home.html <div class="container"> <form th:action="@{/login}" method="post" role="form"> <center><h1 class="text-muted">WELCOME TO ABERDEEN AMS ...
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0answers
48 views

is it an implementation issue or a bug? [on hold]

As much as I know compiler must give an error of incompatible types, as Object Class is parent of all classes, so the statement Parent c2 = new Object(); must be erroneous, but compiler didn't give ...
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0answers
43 views

Java calculator - binary calculations converted into hex/decimal ones and vice versa [on hold]

Over the couple of days i made a very simple calculator in java, which was basically just adding/substracting/etc. two numbers. The two values where stored in double variables, as well as the result. ...
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0answers
135 views

Java Generics: how to extend a self referencing class?

Assume this type hierarchy: Interfaces Node: Basic graph node TreeNode: Node of a tree graph, extends Node PrintableTreeNode: A node which can print itself too! Concrete implementations ...
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2answers
41 views

Using GNU GPL with classpath exception licensed library in a GNU GPL licensed project

I am working on a project that uses ABCL. License of ABCL is GNU GPL with classpath exception, which means we can link this library with independent modules to produce an executable, regardless of the ...
-3
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0answers
40 views

How to deserialize multiple objects from file [on hold]

I have this much code with me. Deserialization works fine for one object but not for many. i even tried by checking while((i=fin.read())!=-1) but it's not working Please help me with it public class ...
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votes
1answer
83 views

Is the use of set / get prefix discouraged for methods if they don't actually mutate / access fields

This could be a quirk of the IDE I am using, Android Studio, or it could be something more nuanced that I don't understand. I have a method setCustomFont that appears as a property in the Structure ...
-7
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3answers
108 views

Why different languages have different syntax?

Different programming language always/most of the time use different syntax. For example take PHP, Java and Python. In Php & Java semicolons are compulsory at the end of the line, yet Python ...
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0answers
38 views

Convert String to Integer Code in Java [on hold]

help me to solve this problem Q: find the largest number in the String by using substring() function? In fact, I did it by using Integer.parseInt() function and it runs, so I was wondering if there ...
2
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2answers
145 views

interpretation of the statement in java

I am confused over the interpretation of the following statement Fruit x= new Fruit(); My interpretation is that the new operator along with Fruit(); creates a new object somewhere in the memory. ...
-4
votes
0answers
35 views

Java Program Output Incorrect [on hold]

I am having a horrible time trying to get this program to output correctly. The program has no errors, but when I run the "test" it outputs: Also when I run the program to enter my own data the ...
-5
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0answers
29 views

About Files converted From OCR? [on hold]

Is there any software or process to find the OCRd files? If anyone have idea on this please reply asap.
-3
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0answers
27 views

I want to retrieve image from mysql database using servlet and show that image along with that user details in table [on hold]

Everything is working well. When I delete Code for Retrieving image then I get user details in table and when I put the code to retrieve image along with the code of printing user details then I only ...
-6
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0answers
22 views

How to build hotel reservation panel with month view in core java [on hold]

I want to build a hotel reservation system for desktop using core java but when i come to reserve a room for multiple dates it becomes brick always, i also want a month view which show booked and ...
0
votes
1answer
27 views

JEE MVC, controller calls the interface instead of the interface implementation

I'm following this tutorial: http://wiki4.caucho.com/Building_a_simple_listing_in_JSP It creates a basic web application in Eclipse using the MVC pattern with Resin as the web container. Here's the ...
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3answers
134 views

How to use Guice for an effective API Design?

I am creating a base API in JavaSE, which includes modules like MVP architecture, Service & Repository Layer, Event Model to fire events between presenter etc. I am trying to implement all best ...
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0answers
12 views

How to pass a string value to a String with “ ” [on hold]

So it's kinda a simple thing but i can't find a way to do it without getting a syntax error.So i want to pass a string value from a variable to another.So lets say i have a variable. String view= ...
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0answers
55 views

Strategy for writing a scalable chat server in Java [on hold]

Currently I'm creating a chat server in Java using socket, seems that is the natural choice for a newbie java programmer. What are the strategies that need to be taken in order to scale the chat ...
0
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0answers
62 views

Pattern to share fields in inheritance

I'm trying to figure out the best way to solve a design issue. I have to be able to clone (I'm cloning them to Apache HttpClient) different types of HttpServletRequest (POST, GET...) and then send ...
0
votes
1answer
20 views

Where to store (data) classes for webservices

So I'm pretty new in my current company and my current task is to create a webservice that sends some serialized java objects from service A to service B using jaxws (webservices). The senior on the ...
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2answers
72 views

guideline on void methods that do not throw exceptions

In our codebase I saw a method that is similar to following: public void doSomething() { try { ... } catch (Exception e) { ... //log something ... } } ...
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2answers
83 views

Efficiently find whether Binary Search Tree is Height Balanced or not?

A binary tree is height balanced if and only if the two subtrees of root are height balanced and the difference between the two subtrees height is at most 1. I implemented a code in java to find ...
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0answers
33 views

.jar file to interact with C++ console application [on hold]

I know this is probably a difficult and/or insane question, but is there any way that I can make a .jar file that can type things into a C++ console application? I made a .jar GUI in netbeans, and I ...
-3
votes
1answer
71 views

Java - Best way to set properties of an object [on hold]

I don't know if there is any difference in performance, or its just a matter of choice, but I am a perfectionist like that, and I'd like to know. Lets say you have the object HolySheet. You can set ...
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0answers
23 views

DDD Request Validation Handling

I stuck somewhere that I can't find a solution! There are plenty of validation questions here, but as far as I see, most of them were asking about entity validation. But what about request validation? ...
-2
votes
0answers
21 views

Difference between Eclipse+STS plugin and STS IDE? [closed]

What is usage difference between Eclipse + STS plugin and only STS IDE in terms of placing xml configurations and web.xml please explain in brief? I know sts has its own pivotal tcServer .But I ...
-4
votes
0answers
60 views

Encrypting a zip file [closed]

Hey guys m new to android, I want to encrypt zip file that i generated. inside the zip file I have files. So I want to encrypt the zip file. Its my first time to work with encryption. I did my own ...
-2
votes
0answers
15 views

anything better than Sikuli-api-1.0.2 [closed]

I need to draw some patterns on a website page as a tutorial, I am using Sikuli API, do we have anything stronger? for example I need to draw Circle around some components but Sikuli circle are too ...
5
votes
1answer
113 views

Where to initialize objects

I have an BallEntity class that is part of a game that uses a Entity Component System architecture. This class have 'components' that are like the attributes of that class. I create and initialize ...
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0answers
43 views

Naming a class: Shadowing or Mirroring or something else?

The following class basically seeks to maintain a copy of the contents of a JMS Topic. The method onMessage() is called whenever a Messages arrived on a JMS Topic. public class TopicListener { ...
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0answers
59 views

Efficient extensions of degree of separation

I'm trying to play around with the 6 degrees of separation problem, specifically the Kevin Bacon game to find alternative ways of playing the game. I want to eventually port it over to MapReduce, but ...
4
votes
1answer
101 views

Separate interface for mutation methods

I've been working on refactoring some code, and I think I may have taken the first step down the rabbit hole. I'm writing the example in Java, but I suppose it could be agnostic. I have an interface ...
3
votes
0answers
84 views

Nested POJOs, exposing collections, detecting changes

I have a couple plain object classes to represent data read from a file. They look something like this: public class Command { private String name; private List<Message> messages; } ...
1
vote
2answers
93 views

Find the maximum number of pairs of numbers that are in a range, between two arrays

Lets say I have two arrays A and B A = {1,2,3} B = {12,11,67} and have max sum value S = 10 How many maximum number of unique pairs can be formed between the two arrays who's sum is less than or ...
1
vote
2answers
88 views

Naming convention for getting the primitive backing a type?

I have a class that is backed by a double value, and I am wondering about accessor method names that preserve abstraction. Based on my experience in Java, there seems to be at least two precedents: ...
1
vote
1answer
126 views

How can I make an object/class inaccessible to Reflection

I am building an API for minecraft called the Quantum API. We all know that reflection can be used to do some nasty stuff to classes, and even cause undefined behavior if used without care. Is there ...
3
votes
2answers
90 views

Does a serializable singleton imply both value and reference semantics at the same time?

I was reading Effective Java, and I came across passages that talk about ways you might implement a serializable singleton, as if this was a perfectly normal thing to do in Java. This immediately ...
0
votes
4answers
197 views

Is collection object better being immutable? [closed]

As per this link, it is an advice that: A good object should never change his encapsulated state. Remember, an object is a representative of a real-life entity, and this entity should stay the ...
10
votes
2answers
398 views

Packaging structure of Java collections (java.util) - why does Iterable sit in java.lang?

As per the below diagram, except for interface Iterable, all the remaining constructs (interface / class / abstract class) sit in same package java.util   Why does Iterable sit in ...
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0answers
30 views

Map-Reduce sorting: before or after partitioning?

At some point, the (key,value) outputs of the mappers are sorted by key.As I understand, this sorting doesnt take place locally on the node of the mapper.So I can think of two possibilites: 1) does ...
2
votes
2answers
165 views

Has-A or Is-A or some strategy pattern?

I am developing a web based application which is about tracking Fleet units. Actually i have already developed the system but in the last six years things changed a bit. Ordinary the software ...
0
votes
0answers
28 views

JavaFX Synchronize DataModel with Business Domain

I am currently working on a javaFX (first time) frontend for one of our applications. For this i'm using a simple MVC pattern where my model classes use properties so that i can directly bind them to ...
10
votes
1answer
292 views

Is it good practice to implement two Java 8 default methods in terms of each other?

I'm designing an interface with two related methods, similar to this: public interface ThingComputer { default Thing computeFirstThing() { return computeAllThings().get(0); } ...
4
votes
3answers
193 views

Java & REST API: How do I check for duplicate before inserting record?

I am developing an application in Java to parse and upload records from a CSV to an online database, via a REST API. While I know for sure that there are no duplicate records in each CSV file, I ...
0
votes
2answers
181 views

Why 'class String' definition has 'final' modifier? [duplicate]

This answer gives an indication that class String is declared final for thread safety, which does not convince. This answer does not convince when it says: And so, you make the classes final. There ...
32
votes
6answers
4k views

What's the point of implementing a Stack using two queues?

I have the following homework question: Implement the stack methods push(x) and pop() using two queues. This seems odd to me because: A Stack is a (LIFO) queue I don't see why you would need ...