Engineering With Java: Digest #46

Handpicked and Curated: The Best Java and Spring Blogs.

Introduction 📝

This week’s collection of articles covers a wide range of topics, from building declarative APIs with Spring AOP and SpEL to comparing Spring Boot's circuit breaker and retry patterns. It also explores optimizing MySQL performance with Releem, constructing AI multi-agent systems in Java, and understanding garbage collection improvements in Java since JDK 8. For Spring Boot users, there’s insight into handling multiple data sources and integrating HelloSign for e-signature workflows, making these resources valuable for enhancing Java-based applications.

Top Picks ⭐

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1. Building a Declarative API with Spring AOP and SpEL

• This article demonstrates how to build a declarative API for cross-cutting concerns like auditing using Spring AOP and SpEL. It explains creating a custom annotation for auditing method invocations and how to use SpEL to extract and process client IDs from method arguments.

• It also introduces Spring AOP to apply the auditing logic non-invasively across methods, allowing flexibility and maintainability. The article includes examples of using SpEL expressions to access method parameters and bind them to evaluation contexts for seamless integration with auditing logic.

Read the article.

2. Spring Boot Circuit Breaker vs Retry

• The article compares the Retry and Circuit Breaker patterns in Spring Boot, highlighting their use cases and differences. Retry is useful for transient failures, repeatedly attempting an operation before failing, and can be implemented using @Retryable from Spring Retry.

• Circuit Breaker, implemented with Resilience4j’s @CircuitBreaker, prevents system overload by halting operations after detecting repeated failures, transitioning between Closed, Open, and Half-Open states.

• The key difference is that Retry keeps trying while Circuit Breaker stops attempts after a threshold. A combination of both enhances resilience, allowing cautious retries when failures subside.

Read the article.

3. GraalVM vs. JVM: Is Native Image the Future of Java Applications?

• This article compares GraalVM's Native Image feature with the traditional JVM. GraalVM compiles Java into native executables, offering faster startup times and lower memory usage, making it ideal for short-lived applications and microservices.

• In contrast, the JVM optimizes long-running applications with JIT compilation, providing a robust ecosystem but at the cost of slower startup and higher memory overhead.

• The comparison highlights the strengths of both technologies depending on use case, with GraalVM focusing on speed and memory efficiency, and the JVM on dynamic optimization for sustained performance.

Read the article.

Latest 🔥

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1. MySQL Performance Tuning with Releem

• This article introduces Releem, a tool designed to enhance MySQL performance through monitoring and optimization. Releem operates on a client-server model, where the agent collects MySQL and system metrics, transmitting them to an online dashboard for analysis.

• The dashboard provides a performance scorecard and visualizations of query response times, throughput, and slow queries.

• Additionally, Releem offers insights into slow-running queries and those contributing most to application latency, aiding in targeted performance improvements.

Read the article.

2. Hidden Gems: Powerful JPA Annotations You Probably Missed

• This delves into lesser-known but potent JPA annotations that can enhance your Java persistence layer. It covers annotations such as @Version for optimistic locking, @SecondaryTable for mapping an entity to multiple tables, @MapKey for using a map as a collection type, and @AssociationOverride for overriding association mappings in embeddable classes.

• These annotations offer advanced capabilities for managing complex data relationships and ensuring data integrity within JPA.

Read the article.

3. Designing AI Multi-Agent Systems in Java

• This article explores constructing AI agents that utilize artificial intelligence to achieve specific goals through a series of steps, potentially reasoning and making adjustments based on outcomes.

• The author presents a practical example: developing a reactive agent to assist users in selecting an ideal vacation destination within a specified country, considering preferences for food, sea, and activities.

• This agent operates by collecting information in parallel, ranking cities based on individual characteristics, and ultimately determining the most suitable city. The implementation leverages ChatGPT models for data gathering and utilizes Fibry, a lightweight Actor System, to manage the process flow and parallelism effectively.

Read the article.

4. How Java Servlets Work: The Backbone of Java Web Apps

• The article explains the role of Java Servlets in web application development, emphasizing their function as server-side components that handle HTTP requests and generate responses.

• Servlets work within a Servlet Container, which manages their lifecycle and processes requests. The article outlines the Servlet lifecycle, including initialization, handling requests with the service method, and sending responses back to the client.

• It details the flow from the browser to the web server and back, providing a visual representation for clarity.

Read the article.

5. How Spring Boot Handles Multiple DataSources Internally

• The article discusses how Spring Boot handles multiple data sources internally. It explains configuring different data sources through application properties, using @Primary to designate a default, and creating separate DataSource, EntityManagerFactory, and TransactionManager beans for each data source.

• Additionally, it touches on using @EnableTransactionManagement to manage transactions across multiple data sources and demonstrates how Spring Boot handles the complexities of switching between them, ensuring proper configuration for each data source.

Read the article.

6. E-signature With HelloSign and Spring boot

• The article explains how to integrate HelloSign for e-signature functionality in a Spring Boot application. It covers the steps of setting up a HelloSign account, obtaining API credentials, and implementing the necessary APIs in a Spring Boot project.

• The integration allows sending documents for signature and retrieving the signed documents programmatically. It also provides code examples to demonstrate the process and discusses handling the authentication and API calls for a seamless e-signature workflow in your application.

Read the article.

7. Garbage Collection in Java - The progress since JDK 8

• This article discusses the significant improvements in Java Garbage Collection (GC) since JDK 8. It highlights various GC algorithms, their differences, and how to choose the right one for your application.

• Upgrading to a recent JDK version can enhance GC performance, reducing overhead associated with automatic memory management. The article also emphasizes the importance of understanding GC basics to make informed decisions for better application performance.

Read the article.

Open Source 🛠️

1. bucket4j

bucket4j is a Java library for rate limiting based on the token-bucket algorithm. It supports distributed and in-memory rate limiting and integrates well with Java applications, including Spring Boot.

Key Features

• In-memory and distributed rate limiting

• Supports Redis, Hazelcast, Infinispan, Ignite, and PostgreSQL for distributed rate-limiting

• API-friendly with a fluent Java DSL

• Works with Spring Boot, providing integration with filters and interceptors

Use Cases

• API rate limiting to prevent abuse

• User-based quotas in web applications

• Distributed rate limiting in microservices

Career Devlopment 📚

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