Snippet

Type-safe Configuration with @ConfigurationProperties

@ConfigurationProperties provides a type-safe way to map external properties (e.g., from application.yml) into Java objects. This is superior to using @Value because it supports hierarchical structures, validation, and easier refactoring.

snippet.java

java

@ConfigurationProperties(prefix = "app.security")
@Component
public class SecurityConfig {
    private String apiKey;
    private List<String> allowedOrigins;
    
    // Getters and Setters are required
    public void setApiKey(String apiKey) { this.apiKey = apiKey; }
    public void setAllowedOrigins(List<String> origins) { this.allowedOrigins = origins; }
    public String getApiKey() { return apiKey; }
    public List<String> getAllowedOrigins() { return allowedOrigins; }
}

spring

Breakdown

prefix = "app.security"

Matches properties starting with this prefix in your configuration file.

List<String> allowedOrigins

Automatically handles comma-separated values or YAML lists into a Java List.

Getters and Setters

Required by Spring to bind properties to the fields of the class.

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Type-safe Configuration with @ConfigurationProperties

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