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YAML Config Files

juneau-config supports YAML config files as an alternative to INI/CFG files.

See the guide: Externalize config with INI/YAML and variables

When to use it​

Use YAML when the config is nested or shared with tools that already read YAML. INI remains the default format.

Example​

A .yml or .yaml config name auto-selects the YAML format.

import org.apache.juneau.config.*;
import org.apache.juneau.config.store.*;

public class YamlConfigExample {

    public static void main(String[] args) throws Exception {
        // Put a YAML file in an in-memory store so the example is self-contained.
        MemoryStore store = MemoryStore.create().build();
        store.update("MyConfig.yaml", "foo:\n  bar:\n    baz:\n      k1: v1\n");

        // A .yaml name auto-selects the YAML format.
        Config config = Config.create().name("MyConfig.yaml").store(store).build();

        System.out.println(config.getString("foo/bar/baz/k1"));
    }
}

Options​

SettingEffect
name("MyConfig.yaml")Picks YAML from the file extension
yaml()Forces YAML for any name, for example MyConfig.cfg
Config c = Config.create()
	.name("MyConfig.cfg")
	.yaml()
	.build();

Section path mapping​

INI section paths map directly to nested YAML maps:

[foo/bar/baz]
k1 = v1
foo:
  bar:
    baz:
      k1: v1

A config lookup like config.getString("foo/bar/baz/k1") works the same for either format.

Notes​

  • INI remains the default format.
  • FileStore now searches cfg,yml,yaml by default.
  • Existing value modifiers and SVL variable resolution continue to work unchanged.

See also​