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Core Java

Interview questions: verify the braces

This is one of the easier coding tasks, but you still can meet it in some preliminary tech screening. The problem looks like this: Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the correct order, "()" and "()[]{}" are all valid but "(]" ...

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FREE IntelliJ IDEA Licenses Giveaway from Java Code Geeks and JetBrains (total value of $447)!

Looking for a powerful, yet simple, Java IDE ? Then we have something especially for you! We are running a contest giving away 3 FREE licenses for the amazing IntelliJ IDEA IDE. Every aspect of IntelliJ IDEA is specifically designed to maximize developer productivity. Together, powerful static code analysis and ergonomic design make development not only productive but also an ...

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Adventures In Modernization: Strategy + Example Converting COBOL To Java

At Keyhole Software we are in large part a modernization company. We have consultants who specialize in moving old to new, renovating dilapidated code bases, and designing brighter futures for enterprises that have been vendor-locked for most of their existence. As an interesting side effect of these experiences, we have come across some repeated patterns and strategies for how to ...

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Elasticsearch for Java Developers: Introduction

1. Introduction Effective, fast and accurate search functionality is an integral part of vast majority of the modern applications and software platforms. Either you are running a small e-commerce web site and need to offer your customers a search over product catalogs, or you are a service provider and need to expose an API to let the developers filter over ...

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How Java’s Built-In Garbage Collection Will Make Your Life Better (Most of the Time)

Solve App Problems 10x Faster with AppDynamics – Monitor production apps at code-level depth with minimal overhead. Start a FREE Trial! “No provision need be made for the user to program the return of registers to the free-storage list.” This line (along with the dozen or so that followed it) is buried in the middle of John McCarthy’s landmark paper, ...

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Why Elvis Should Not Visit Java

I was recently involved in quite a long Twitter discussion regarding Java’s Optional, type systems that distinguish nullable and non-nullable types and the the Elvis operator, which allows null-safe member selection. The latter was peddled as a killer feature for succinct null-handling, which I strongly disagree with. My opinion on the matter is that without a type system that allows ...

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Decorating Envelopes

Sometimes Very often I need a class that implements an interface by making an instance of another class. Sound weird? Let me show you an example. There are many classes of that kind in the Takes Framework, and they all are named like *Wrap. It’s a convenient design concept that, unfortunately, looks rather verbose in Java. It would be great to ...

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