Java Sprintboot

Abstract

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• Java Spring Boot is a framework for building Java-based web applications and microservices

Important

It simplifies development by providing

• pre-configured templates
• reducing boilerplate code
• enabling rapid application development.

It is built on the Spring framework, offering features like

• dependency injection
• embedded servers (e.g., Tomcat)
• seamless integration with databases

Java Springboot Dependency Injection

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@Value

@Value("${my.property:defaultValue}")
private String myProperty; // Uses defaultValue if my.property is not set

• Injects values from external configuration (like application.properties or application.yml) into Spring-managed beans

Java Springboot Web Request Mapping

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@RequestMapping

@RequestMapping(value = "/myPath", method = RequestMethod.GET)
public String myHandler() {
    return "myView";
}

• Can specify HTTP methods, request parameters, and path variables

@GetMapping

@GetMapping("/users")
public List<User> getUsers() {
    return userService.getAllUsers();
}

• Maps HTTP GET requests

@PostMapping

@PostMapping("/users")
public User createUser(@RequestBody User user) {
    return userService.createUser(user);
}

• Maps HTTP POST requests

@PutMapping

@PutMapping("/users/{id}")
public User updateUser(@PathVariable Long id, @RequestBody User user) {
    return userService.updateUser(id, user);
}

• Maps HTTP PUT requests

@DeleteMapping

@DeleteMapping("/users/{id}")
public void deleteUser(@PathVariable Long id) {
    userService.deleteUser(id);
}
 

• Maps HTTP DELETE requests