🎯 Eric Anicet K.’s Post

The ultimate Java Backend Cheat Sheet. 📄🔥 Everything you need to master: 🔹 Core & Advanced Java 🔹 Spring Boot & REST APIs 🔹 SQL & Performance Tuning 🔹 Testing (JUnit/Mockito) 🔹 Git & GitHub Download/Save the document below! Found this helpful? 👉 Follow Surya Mahesh Kolisetty for more. 👉 Repost for your fellow devs. #SoftwareDevelopment #Backend #Java #LearningResources #TechTips #Developers #cfbr #connections

#java #springboot #tips 🚫 Stop using field injection in Spring Boot. Here’s why: Most developers write this: @Autowired private UserService userService; ✅ Use constructor injection instead: @Service @RequiredArgsConstructor public class OrderService { private final UserService userService; // immutable + testable } Why it matters: • Fields are final → truly immutable • Easier to unit test without Spring context • Fails fast at startup if bean is missing • Works perfectly with Lombok’s @RequiredArgsConstructor This is also the official Spring recommendation since Spring 4.x. #Java #SpringBoot #CleanCode #BackendDev

“Stuck in legacy Java” is usually misdiagnosed The real issue? That experience doesn’t translate into anything valuable outside your company Same codebase Different outcomes: One developer says: “Maintained a monolith” Another says: “Removed a major bottleneck and improved response times under load” That difference is what gets noticed If your experience isn’t opening doors, there’s a reason https://bit.ly/483A7IW

Spring Boot HandlerExceptionResolver — Advanced error handling 🔥 Most devs use @ControllerAdvice… but there’s a deeper layer 👇 👉 HandlerExceptionResolver It gives full control over: ✔ Exception handling ✔ HTTP response ✔ Error mapping 💡 Why use it? ✔ Fine-grained control ✔ Custom framework-level handling ⚠️ Use case: When @ExceptionHandler is not enough 👉 Example: Handle all exceptions globally with custom logic This is how frameworks are built internally 💯 #SpringBoot #Java #ExceptionHandling

Java and Kotlin run on the same JVM, share the same ecosystem, and can even call each other's code. So why does picking one still feel complicated? Because the right choice depends on what you're building, not which language is objectively better. This decision tree makes it straightforward (see photo below) The full guide by roadmap.sh goes deeper, covering key differences in syntax, null safety, concurrency, and long-term maintenance so you can make a decision now that actually holds up later. Check the link in the comments.

Spring Boot @Conditional — Hidden superpower ⚡ You can load beans conditionally! Examples: ✅ @ConditionalOnProperty ✅ @ConditionalOnMissingBean ✅ @ConditionalOnClass 💡 Use case: Load bean ONLY when needed Example: @Configuration @ConditionalOnProperty(name="feature.enabled", havingValue="true") 👉 Feature toggles made easy 🔥 ✔ Better flexibility ✔ Environment control ✔ Cleaner configs Most developers don’t use this — big mistake ❌ #SpringBoot #Java #BackendDeveloper

Spring Boot @Primary — Resolve multiple bean conflicts ⚡ Ever seen this error? “No qualifying bean of type found” ❌ Happens when: 👉 Multiple beans of same type exist Solution 👇 @Primary public class MyServiceImpl implements MyService {} 💡 What it does: Marks default bean when multiple exist Alternative: 👉 Use @Qualifier ⚠️ Mistake: Not handling multiple beans properly 👉 Leads to runtime errors Clean DI = stable application 🔥 #SpringBoot #Java #DependencyInjection

☕ Java 26 — JEP 516: Ahead-of-time object caching with any GC # Example JVM launch using a GC that now works with AOT object caching java -XX:+UseZGC -XX:+AOTStreamableObjects -jar app.jar • This is Project Leyden work aimed at improving startup and warmup. • The important change in JDK 26 is that ahead-of-time object caching is no longer tied to a specific garbage collector. • That means more applications, including ones using ZGC, can benefit from faster cold starts. #java #java26 #leyden #jep16 #aot Go further with Java certification: Java👇 https://bit.ly/javaOCP Spring👇 https://bit.ly/2v7222 SpringBook👇 https://bit.ly/springtify JavaBook👇 https://bit.ly/jroadmap

🚀 Java just got a massive upgrade… and most developers are not talking about it. 👉 Virtual Threads (Java 21) Traditionally: Handling multiple requests = heavy threads + high memory ❌ Now with Virtual Threads: ✔ Lightweight threads ✔ Handle thousands of requests ✔ Better performance with less resources --- 💡 What this means: • Faster backend systems • Better scalability • Improved microservices performance --- 📌 Example: Thread.startVirtualThread(() -> { System.out.println("Hello from Virtual Thread"); }); --- Java is evolving faster than most people think. --- 💬 Do you think Java can compete with Node.js in scalability now? #Java #BackendDevelopment #Programming #SoftwareEngineering #JavaDeveloper

🚀 JVM, JRE, JDK – Quick View 🔹 JDK → Develop Java apps 🔹 JRE → Run Java apps 🔹 JVM → Executes bytecode 💡 Flow: .java → .class → JVM 🎯 Relation: JDK → JRE → JVM #Java #JVM #JDK #Backend