Quick tip: Referencing other Properties in Spring

In Spring property (or yaml) files we can reference other properties using the ${..} syntax.

For example:

external.host=https://api.external.com
external.productService=${external.host}/product-service
external.orderService=${external.host}/order-service

If we now access the external.productService property (e.g. by using the @Value annotation) we will get the value https://api.external.com/product-service.

For example:

@Value("${external.productService}")
private String productServiceUrl; // https://api.external.com/product-service

This way we can avoid duplication of commonly used values in property and yaml files.