Best of Baeldung — January 2025

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   Baeldung·1y

   Implement Feature Flags in Java With Unleash

   Feature flags, or feature toggles, enable the activation and deactivation of application functionalities without altering the codebase. Unleash is an open-source tool for managing these flags across multiple environments. This guide walks through setting up Unleash locally, configuring a feature toggle, and integrating them into a Java application using Spring Boot. The setup ensures features can be toggled in real-time, improving development cycles and enabling controlled feature rollouts.

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   Baeldung·1y

   Kafka Producer and Consumer Message Acknowledgement Options

   The tutorial explains the acknowledgment options available for producers and consumers in Apache Kafka, detailing how the three producer acknowledgment modes (none, leader, and all) impact message reliability and system performance. It also covers essential consumer configuration properties, such as group ID, auto offset reset, enable auto commit, and auto commit interval, which affect consumer message processing and reliability. Understanding these options allows developers to balance performance and reliability for different use cases.

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   Baeldung·1y

   Float vs. Double in Java

   Selecting the right numeric data type in Java is crucial for performance and accuracy. The float type is a 32-bit single-precision floating-point, making it memory-efficient and suitable for embedded systems, while the double is a 64-bit double-precision type, offering higher precision and a broader range, ideal for scientific computations and financial analyses. Developers must consider their application's needs regarding precision, memory usage, and performance when choosing between float and double.

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   Baeldung·1y

   A Guide to One-Time Token Login in Spring Security

   One-time token login (OTT) in Spring Boot applications helps balance ease of use and security, ideal for infrequent logins. It simplifies authentication by sending a time-limited token via email or SMS for user login instead of traditional passwords. The tutorial covers implementing OTT with Spring Boot and Spring Security, including necessary configurations, token generation, and delivery methods, concluding with manual and automated testing guidelines.

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   Baeldung·1y

   Introduction to JLine 3

   JLine is a library for handling console input, similar to GNU Readline or ZSH. This guide walks through setting up dependencies for JLine, creating Terminals and LineReaders, and the different features like history management and command completion. The tutorial also covers using various completers for enhancing user input handling.

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   Baeldung·1y

   Introduction to New Relic for Java

   New Relic's Application Performance Monitoring (APM) tool helps monitor and analyze application performance by centralizing performance data. This tutorial covers setting up the New Relic Java agent, configuring custom instrumentation, tracing requests, and setting up alerts to improve observability and proactive management of application performance.

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   Baeldung·1y

   Introduction to h2o

   Explore the h2o platform to create, train, and tune machine learning models. This tutorial covers the installation of h2o, preparing datasets, training models with algorithms like Random Forest, using AutoML, and implementing the models in Java applications. It provides a step-by-step guide for efficiently building and deploying models without requiring extensive knowledge of Python or additional libraries.

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