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How to Convert List to Map in Java 1. Overview Converting List to Map is a common task. In this tutorial, we’ll cover several ways to do this. We’ll assume that each element of the List has an identifier which will be used as a key in the resulting Map. 2.… Continue Reading java-list-to-map
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Download a File From an URL in Java 1. Introduction In this tutorial, we’ll see several methods that we can use to download a file. We’ll cover examples ranging from the basic usage of Java IO to the NIO package, and some common libraries like Async Http Client and Apache Commons… Continue Reading java-download-file
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Preserve the History of Reddit Post Submissions 1. Overview In this installment of the Reddit App case study, we’re going to start keeping track of the history of submission attempts for a post, and make the statuses more descriptive and easy to understand. 2. Improving The Post Entity First, let’s… Continue Reading reddit-app-maintain-full-history-of-post-operations
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Java Optional – orElse() vs orElseGet() 1. Introduction The API of Optional typically has two methods that can cause confusion: orElse() and orElseGet(). In this quick tutorial, we’ll look at the difference between those two and explore when to use each one. 2. Signatures Let’s first start with the basics by looking… Continue Reading java-optional-or-else-vs-or-else-get
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Java InputStream to String 1. Overview In this tutorial we’ll look at how to convert an InputStream to a String, using Guava, the Apache Commons IO library, and plain Java. This article is part of the “Java – Back to Basic” series here on Baeldung. 2. Converting with Guava Let’s… Continue Reading convert-input-stream-to-string
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Introduction to Hazelcast Jet 1. Introduction In this tutorial, we’ll learn about Hazelcast Jet. It’s a distributed data processing engine provided by Hazelcast, Inc. and is built on top of Hazelcast IMDG If you want to learn about Hazelcast IMDG, here is an article for getting started. 2. What is Hazelcast… Continue Reading hazelcast-jet
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Ant Colony Optimization 1. Introduction The aim of this series is to explain the idea of genetic algorithms and show the most known implementations. In this tutorial, we’ll describe the concept of the ant colony optimization (ACO), followed by the code example. 2. How ACO Works ACO is a genetic… Continue Reading java-ant-colony-optimization
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A Guide to Java HashMap 1. Overview In this article, we’ll see how to use HashMap in Java, and we’ll look at how it works internally. A class very similar to HashMap is Hashtable. Please refer to a couple of our other articles to learn more about the java.util.Hashtable class… Continue Reading java-hashmap
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Spring Security OAuth 2 Guides OAuth2 Basics + Spring REST API + OAuth2 + AngularJS + Using JWT with Spring Security OAuth + Testing an OAuth Secured API with Spring MVC Advanced Scenarios with OAuth2 + Spring Security and OpenID Connect + Simple Single Sign-On with Spring Security OAuth2 + OAuth2.0… Continue Reading spring-security-oauth
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A Simple Guide to Connection Pooling in Java 1. Overview Connection pooling is a well-known data access pattern, whose main purpose is to reduce the overhead involved in performing database connections and read/write database operations. In a nutshell, a connection pool is, at the most basic level, a database connection… Continue Reading java-connection-pooling
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