Dan Vega’s Post

💡 What’s the difference between @RequestParam, @PathVariable, and @RequestBody in Spring Boot? Here's a quick summary with use cases 👇 1️⃣ Use @RequestParam for query params 2️⃣ @PathVariable for resource IDs 3️⃣ @RequestBody for JSON input Clean APIs = happy clients. #springboot #restapi #java

Master JSON Serialization in Quarkus — The Right Way This hands-on guide walks through real solutions using Jackson and Quarkus REST. Read the full tutorial here 👇 https://lnkd.in/dWfWBx-T #Java #Quarkus #Jackson #JSON #SoftwareDevelopment #API #BackendEngineering

🔒 Understanding the final keyword in Java The final keyword adds safety and stability to your code by preventing unwanted changes. It can be used in three main ways: 🧩 With Variables – once assigned, the value can’t be changed. 🧩 With Methods – prevents overriding in subclasses. 🧩 With Classes – stops inheritance altogether. Simple yet powerful — final protects what’s meant to stay constant. #Java #OOPs #finalKeyword #JavaConcepts #CodingBasics #LearnJava

Day 51/100 – #100DaysOfCode 🚀 | #Java #LinkedList #Heap ✅ Problem Solved: Merge k Sorted Lists (LeetCode) 🧩 Problem Summary: You’re given k sorted linked lists. The task is to merge them into one sorted linked list. 💡 Approach Used: Use a Min-Heap (PriorityQueue) to always pick the node with the smallest value among all current heads of the lists. Steps: Push the head of each non-null list into the Min-Heap. Extract the smallest, attach to result, and push its next node (if exists). Continue until heap becomes empty. This ensures efficient merging. ⚙️ Time Complexity: O(N log k) 📦 Space Complexity: O(k) ✨ Takeaway: When multiple sorted streams exist, heaps provide clean and optimal merging. #Java #LeetCode #Heap #LinkedList #ProblemSolving #CodingChallenge #100DaysOfCode

#DevDiaries 🧑💻 💭 Ever wondered how Spring Boot automatically converts your Java objects to JSON (and vice versa)? The answer is — Jackson Spring Boot uses Jackson by default for JSON serialization and deserialization, seamlessly turning your Java objects ↔ JSON in REST APIs. You can customize this behavior with simple annotations: @JsonProperty → Rename JSON fields @JsonIgnore → Skip certain fields @JsonInclude(Include.NON_NULL) → Exclude null values @JsonFormat(pattern = "yyyy-MM-dd") → Format dates Jackson is the silent hero behind Spring Boot APIs — making JSON handling effortless and clean. #SpringBoot #Jackson #Java #JSON #BackendDevelopment #JavaDeveloper #LearnWithMe #DevDiaries

Where does your technical debt really hide? Cyclomatic complexity, churn, coupling — Richard Gross demonstrates how to measure and visualize deep problems in large codebases objectively. Read now on JAVAPRO: https://lnkd.in/eENXrUwD #Java #DomainDrivenDesign #LegacyCode

BeanPostProcessor & BeanFactoryPostProcessor BeanPostProcessor allows custom logic after bean initialization. It helps modify bean instances right before use. BeanFactoryPostProcessor modifies bean definitions before creation. Useful for adjusting configuration metadata dynamically. Both provide powerful customization for advanced scenarios. #SpringFramework #Java #SoftwareEngineering #BackendDevelopment

🚀 Building a Thread-Safe Map from a List in Java Ever needed to convert a List into a ConcurrentHashMap for fast lookups and safe concurrent access? Here’s an approach using Java Streams and Collectors.toMap(). 🔹 Key Idea: Transform your list into a map where keys = unique IDs and values = actual objects (Function.identity() style). 🔹 Why it matters: ⚡ Thread-safe lookups for concurrent environments 💡 Declarative one-liner using Java Streams 🧩 Merge function prevents duplicate-key exceptions 🔒 Backed by ConcurrentHashMap for safe updates #Java #SpringBoot #BackendDevelopment #ConcurrentProgramming #CleanCode #JavaStreams #ThreadSafe #CodingBestPractices #SoftwareEngineering #Developers

Before the release of Spring Boot 4, it was necessary to explicitly include the following dependency for JSON serialization and deserialization: <dependency> <groupId>com.fasterxml.jackson.dataformat</groupId> <artifactId>jackson-dataformat-xml</artifactId> </dependency> However, starting with Spring Boot 4.0.x, this functionality is included with the spring-boot-starter-webmvc artifact or dependency as a tool with dependency as a spring-boot-starter-jackson, and the import changes accordingly, exhibiting a transitive nature. For more details about Jackson 3 support in Spring Boot 4, please read through https://lnkd.in/gvGN58M7 Spring I/O #springboot4 #springframework #java