Чашечка Java

Простой пример написания Dockerfile. Использование многоэтапной сборки Всем привет! В данной статье хочу показать простой пример написания Dockerfile, объяснить как это все работает, а также показать на примере использование многоэтапной сборки. Для понимания данной статьи необходимы минимальные знания Docker, а также для использования примеров - установленный Docker Desktop локально на компьютере. Вначале немного теории. Dockerfile - это файл, который содержит инструкции для сборки образа. На основании образа создается и запускается контейнер. Обратимся к официальной документации https://docs.docker.com/get-started/overview/ Читать: https://habr.com/ru/post/713942/?utm_campaign=713942

3 Examples of Anonymous Class to Learn Lambda Expression better in Java 8 Why I am talking about Anonymous class now when many Java programmers have already switched to Java 8 and many have already moved on from Anonymous class? Well, I am doing it because I am seeing programmers who find it difficult to write and read code using lambda expression in new Java 8 way. It's also my experience that if you know the problem first, you can understand the solution better. Some of you might remember, the opening scene of MI 2, when Nekhorovich says to Dimitri that "Every search for a hero must begin with something that every hero requires, a villain. Therefore, in our search for a hero, Belairiform, we created the monster, Chimera". Well, Anonymous class is not that sort of monster but it is one of the reason which makes lambda expression hero of Java 8. Java Interview questions and tutorials Read: http://www.java67.com/2023/01/3-examples-of-anonymous-class-to-lambda.html

Top 27 Spring Security Interview Questions Answers for Java Developers Hello guys, if you are preparing for Java and Spring Developer interview then you should prepare about Spring Security. Since Security is an important topic and Spring security is the most popular framework to implement security in Java web applications, there is always a few questions based upon Spring Security in Java developer interviews. In the past, I have shared Spring Boot questions, Spring Data JPA Question, Spring Cloud Questions, and Microservices Interview Questionsand in this article, I will share 20 popular Spring security questions for practice. I have also shared answers so that you can revise key Spring security concepts quickly but if you think that you need more preparation on certain topic then you can also checkout this list of best Spring Security courseswhere I have shared online courses to learn Spring security in depth. Java Interview questions and tutorials Read: http://www.java67.com/2022/06/spring-security-interview-questions.html

Top 20 Jenkins and CI/CD Interview Questions Answers for Java Developers Hello guys, if you are preparing for Java developer interview or DevOps Interview, one tool which you should know well is Jenkins, the king of Continuous Integration and Continuous build, and one of the most desirable skill companies look on experienced programmers now a days. Earlier, I have shared best free Jenkins courses for programmers to learn this useful tool as well as Interview questions on DevOps, Docker, and Kubernetes and in this article, I am going to share 20 frequently sked Jenkins and CI/CD Interview questions with answers for both beginners and experienced developers. Java Interview questions and tutorials Read: http://www.java67.com/2022/09/jenkins-interview-questions-answers-for.html

Top 20 Agile and Scrum Interview Questions and Answers for PM, Programmers and Testers Hello guys, ,if you are preparing for Software Developer interview then it makes to prepare questions on Agile and Scrum methodology. Agile is the standard way to develop software and most of the companies, both big and small follows Agile to develop and deliver Software. Earlier, I have shared free Agile and Scrum online coursesto learn these useful technologies for Software development and today, I am going to share 20 Agile and Scrum interview questions with answers. But, before we get to the all-important interview questions that will help you land your dream software job, let me tell you something about Agile and Scrum. Java Interview questions and tutorials Read: http://www.java67.com/2022/06/top-20-agile-and-scrum-interview.html

Tarantool Data Grid + Java = … В последнее время всё большую популярность набирает Tarantool — платформа in-memory вычислений с гибкой схемой данных, включающая в себя NoSQL-базу данных и сервер приложений. В этой статье я хочу рассказать об одной из его реализаций — Tarantool Data Grid (TDG). Читать: https://habr.com/ru/post/713592/?utm_campaign=713592

Mockito 5 Supports Mocking Constructors, Static Methods and Final Classes Out of the Box Mockito has released version 5, switching the default mockmaker to mockito-inline in order to better support future versions of the JDK and allows mocking of constructors, static methods and final classes out of the box. The baseline increased from Java 8 to Java 11, as supporting both versions became costly and managing changes in the JDK such as with the SecurityManager proved difficult. By Johan Janssen Read: https://www.infoq.com/news/2023/01/mockito-5/

Java News Roundup: JDK 20 in Rampdown Phase 2, New JEP Drafts, JobRunr 6.0, GraalVM 22.3.1 This week's Java roundup for January 23rd, 2023, features news from OpenJDK, JDK 20, JDK 21, GraalVM 22.3.1, TornadoVM 0.15, Spring Cloud Azure 5.0, Spring Shell 3.0.0 and 2.1.6, Spring Cloud 2022.0.1, Quarkus 2.16 and 3.0.Alpha3, Micronaut 3.8.3, JobRunr 6.0, MicroStream 8.0-EA2, Hibernate 6.2.CR2, Tomcat 10.1.5, Groovy 4.0.8 and 2.5.21, Camel Quarkus 2.16, JDKMon 17.0.45 and Foojay.io at FOSDEM. By Michael Redlich Read: https://www.infoq.com/news/2023/01/java-news-roundup-jan23-2023/

3 Examples of flatMap() of Stream in Java Hello guys, if you are doing Java development then you must have come across the flatMap() method on Stream and Optional Class. The flatMap() method is extension of map() function as it does both flattening and mapping (or transformation) instead of just transformation done by map() method. I have explained the difference between map() and flatMap() earlier in detail, but just to revise, let's revisit it. If you have a list of String e.g. {"credit", "debit", "master", "visa"} then you can use the map() method to get a list of integer where each value is length of corresponding String e.g. list.stream().map(s -> s.length()) will produce {6, 5, 6, 4}. This is called transformation because you have transformed an stream of String to a Stream of integer. Java Interview questions and tutorials Read: http://www.java67.com/2023/01/3-examples-of-flatmap-of-stream-in-java.html

From Zero to Hero: определите ваш уровень решения LeetCode задач от 1 до 5 В этой статье я хочу написать про мой опыт взаимодействия с платформой LeetCode, и описать свою подготовку к интервью в FAANG подобные компании путем разбиения ее на уровни. А какой у вас уровень? Читать: https://habr.com/ru/post/713498/?utm_campaign=713498

Top 50 Advanced Java Garbage Collection and Performance Interview Questions and Answers Hello Java Developers, If you have gone through any Java Developer interview, particularly for a senior developer role then you know that a good knowledge of JVM internals and Garbage collection is important. Even though Java and JVM take care of memory management for you, bad code can still cause memory leaks and performance issues. For example, if you are creating millions of objects in a loop or keeping an un-intended reference of dead objects then you are putting additional strain on the Garbage collector and creating a memory leakin your application. You cannot blame Java and JVM for that and the only way to avoid such errors is to know about how Garbage collection works. Java Interview questions and tutorials Read: http://www.java67.com/2020/02/50-garbage-collection-interview-questions-answers-java.html

Top 40 Perl Interview Questions and Answers for Programmers Hello guys, if you have been working as a professional Software developer then you may have heard about Perl, one of the most powerful scripting languages. Perl is really great when it comes to creating reports, write scripts to analyze text, and connect to DB, load data and generate reports. Perl is even more important for IT support professionals, business analysts, and IT professionals who need to work in the field of operations. That's why Perl questions are quite common during Software developer and IT support interview, especially if the Job description mention Perl or you have added Perl as a skill in your resume or LinkedIn Profile. Java Interview questions and tutorials Read: http://www.java67.com/2020/05/perl-interview-questions-and-answers.html

[Solved] How to check if two String are Anagram in Java? Example Hello guys, if you are preparing for Coding interviews then you already know that String is one of the most popular topics. You will be bound to get some string-based coding problems on interviews. If not, you have come to the right place becuase we'll look at one of the most popular String programming interview questions today, how to check if two given strings are Anagram of each other?Two String is said to be an anagram of each other, if they contain exactly the same characters but in a different order. For example "ARMY" and "MARY" are an anagram of each other because they contain the exact same characters 'A', 'R', 'M' and  'Y'. Java Interview questions and tutorials Read: http://www.java67.com/2019/04/how-to-check-if-two-string-are-anagram.html

How to create a String or int Array in Java? Example Tutorial There are several ways to create an array in Java, for example, you can declare the array without initializing it, or you can create and initialize the array in the same line. If you want to make an array with values, then you need to first decide which type of array you want to create? e.g., do you want a String array, which can contain String objects like "abc," "def," or do you want to create an int array that contains int values like 10, 20, etc. In Java, you can create an array of any type, including primitives like byte, int, long, and objects like String, Integer, and other user-defined objects. Let's some code to make a new array in Java. Java Interview questions and tutorials Read: http://www.java67.com/2019/10/how-to-make-new-array-in-java.html

How to find 2nd, 3rd or kth element from end in linked list in Java? Example [Solved] Hello guys, today, I am going to discuss one of the important linked list based coding problems from interviews -how to find the Kth element from the end? This question is also asked as to how do you find the 3rd element from the last of a singly linked list in one passor write a Java program to find the 5th element from the tail of a given linked list in one iteration. In this article, you will learn the programming technique so that you can solve any variant of this problem, I mean the Kth node from the tail problems and some linked list-based challenges. The difficulty in this question is that you need to solve the problem in one iteration or one pass. This means you cannot traverse the linked list again. I mean you cannot go till the end then traverse back to the Kth element. Java Interview questions and tutorials Read: http://www.java67.com/2020/04/how-to-find-kth-node-from-end-in-linked-list-java.html

Difference between array and Hashtable or HashMap in Java A couple of days back someone asked me about the difference between an array and a hashtable, though this is a generic data structure and programming question, I'll answer it from both a general programming perspective as well on Java perspective where Hashtable is not just a data structure but also a class from Java Collection API. Even though both array and hashtable data structure are intended for fast search i.e. constant time search operation also known as O(1) search, the fundamental difference between them is that array require an index while hash table requires a key which could be another object. Java Interview questions and tutorials Read: http://www.java67.com/2021/08/difference-between-array-and-hashtable.html

Top 25 Linked List Interview Questions for Java Programmers Hello guys, if you are preparing for Software Development interview or want to become a Software Engineer in 2023 then you must pay full attention to two important topics: first is Data Structure and Algorithms, and second is System Design. These two topics are very essential and you will always find questions from these in any coding interview. They are also the most difficult to crack as they are very vast, no matter how much you will prepare there will be certain questions which you don't know but if you have solid knowledge of fundamental data structure like array, linked list, binary tree, hash table, heap, and graphs as well sorting and searching algorithms like quicksort, merge sort, selection sort, insertion sort, binary tree as well advanced String and graph algorithms then you can still do well. Java Interview questions and tutorials Read: http://www.java67.com/2022/11/15-linked-list-interview-questions-for.html

Top Java Blogs Weekly: Best of 5/2023 Best of Top Java Blogs, year 2023, week 5 Read: https://www.topjavablogs.com/news/best-of-5-2023