How can properties from application.properties be injected into a bean in Spring?

In Spring, properties from the application.properties file can be injected into beans in several ways:

1. @Value annotation — allows injecting individual values by key:

@Component
public class MyBean {
    @Value("${my.property}")
    private String myProperty;

    // getters, methods
}

2. Using @ConfigurationProperties — allows binding a group of properties to a class, convenient for structured settings:

@Component
@ConfigurationProperties(prefix = "my")
public class MyProperties {
    private String property;
    // getters and setters
}

And in application.properties:

my.property=value

3. Via Environment — properties can be obtained programmatically:

@Autowired
private Environment env;

public void someMethod() {
    String value = env.getProperty("my.property");
}

Most often, @Value is used for simple cases, and @ConfigurationProperties for groups of related settings.