@RequestParam, @PathVariable, and @RequestBody in Spring Boot explained

#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

Want to learn how to build a GraphQL API in #Java in less than 20 minutes? I got you covered in this talk I gave at SpringOne this year. https://lnkd.in/ewUhQimi

💡 Spring Boot Annotations Cheat Sheet Spring Boot’s magic lies in its annotations — small but powerful tools that make development fast and clean ⚡ Here are some must-know annotations every Java developer should master 👇 🔹 @SpringBootApplication → Combines @Configuration, @EnableAutoConfiguration & @ComponentScan 🔹 @RestController → @Controller + @ResponseBody (handles REST APIs) 🔹 @Autowired → Handles Dependency Injection 🔹 @Component / @Service / @Repository → Marks Spring-managed beans 🔹 @RequestMapping / @GetMapping / @PostMapping → Maps HTTP endpoints 🔹 @Value / @ConfigurationProperties → Injects values from properties files 🔹 @Transactional → Handles database transactions Master these, and Spring Boot feels like second nature. 🌱 💬 Which annotation do you use most often in your projects? #SpringBoot #Java #DesignPatterns #CleanCode #BackendDevelopment #SoftwareEngineering

💡 Java Tip of the Day: Immutability = Simplicity + Safety Immutable classes are thread-safe and easy to reason about. ✅ Example: public final class User { private final String name; public User(String name) { this.name = name; } public String getName() { return name; } } No setters, all fields final, and the class itself final. Frameworks like String, Integer, and even DTOs often rely on immutability to ensure consistency. 💬 Do you use immutability often in your codebase? #Java #CleanCode #ThreadSafety #CodeTips

🎯 Using @Qualifier in Spring When multiple beans of the same type exist, @Qualifier helps specify which bean should be injected. It works hand-in-hand with @Autowired to resolve dependency conflicts. This ensures clear control over which implementation is wired into the application. 🎛️ #SpringFramework #SpringBoot #Java #Qualifier #DependencyInjection #SoftwareDevelopment

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

🔒 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

The Subtle Trap of Optional in Java 💭 Optional was meant to prevent NullPointerException but misuse can make code worse! ❌ Returning Optional from setters ❌ Using Optional fields in entities ❌ Serializing Optional with Jackson (it’ll break your JSON mapping) ✅ Correct use: Method return types to signal absence of value. Example: Optional<User> user = userRepository.findByEmail(email); user.ifPresent(System.out::println); 💭 Have you seen Optional abused in your codebase? #Java #CleanCode #BestPractices

🚀 Accessing and Modifying Fields Dynamically (Java) Reflection allows you to access and modify the values of fields (including private fields) of an object at runtime. You can obtain a `Field` object representing the field you want to access or modify. For private fields, you need to call `setAccessible(true)` to bypass access restrictions. Then, you can use `get()` to retrieve the field's value and `set()` to modify it. This capability can be useful for debugging, testing, and serialization. #Java #JavaDev #OOP #Backend #professional #career #development

🔒 Encapsulation in Java — The Hidden Power Behind Clean Code Encapsulation simply means wrapping data and methods into a single unit (class). It helps in data security and prevents users from entering invalid data using private variables and getter–setter methods. Think of it like a capsule 💊 — all the important ingredients packed safely inside! #Java #OOPs #Encapsulation