In which cases is it preferable to use XML configuration instead of Java language configuration or their combination?

XML configuration in Java applications is traditionally used for setting up components, especially in frameworks like Spring. XML is preferred in the following cases:

• When you need to separate configuration from code so that it can be changed without recompilation.
• For centralized management of settings, especially in large projects.
• If support for tools that work with XML (e.g., visual editors) is required.

Java-based configuration is convenient when:

• You want to leverage type safety and auto-completion in IDEs.
• The configuration depends on logic that is easier to express programmatically.
• It is desirable to reduce the number of external files and simplify maintenance.

A combination of XML and Java configuration is used when some settings are more conveniently kept in XML (e.g., external parameters), and others in code (e.g., beans with logic). This allows flexible management of configuration, utilizing the strengths of both approaches.