added method subset(…) to Configuration interface, added implementation in JsonConfig

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

build.gradle.kts

@@ -11,7 +11,6 @@ spotless {
         target("**/src/**/java/**/*.java")
         removeUnusedImports()
         importOrder()
-        clangFormat("18.1.8").style("file:config/clang-format")
         licenseHeader("/* © SRSoftware 2024 */")
     }
 }

de.srsoftware.configuration.api/build.gradle.kts

@@ -9,7 +9,7 @@ object Meta {
     val COMPONENT_TYPE = "java" // "java" or "versionCatalog"
     val GROUP = "de.srsoftware"
     val ARTIFACT_ID = "configuration.api"
-    val VERSION = "1.0.0"
+    val VERSION = "1.0.1"
     val PUBLISHING_TYPE = "AUTOMATIC" // USER_MANAGED or AUTOMATIC
     val SHA_ALGORITHMS = listOf("SHA-256", "SHA-512") // sha256 and sha512 are supported but not mandatory. Only sha1 is mandatory but it is supported by default.
     val DESC = "SRSoftware Configuration API"

de.srsoftware.configuration.api/src/main/java/de/srsoftware/configuration/Configuration.java

@@ -44,4 +44,12 @@ public interface Configuration {
 	 * @throws IOException if altering the configuration fails
 	 */
 	<C extends Configuration> C set(String key, Object value) throws IOException;
+
+	/**
+	 * get a subset of this configuration
+	 *
+	 * @param key specifies, which subset is requested
+	 * @return the part of the Configuration which is located at the key
+	 */
+	Optional<? extends Configuration> subset(String key);
 }

de.srsoftware.configuration.json/build.gradle.kts

@@ -14,7 +14,7 @@ object Meta {
     val COMPONENT_TYPE = "java" // "java" or "versionCatalog"
     val GROUP = "de.srsoftware"
     val ARTIFACT_ID = "configuration.json"
-    val VERSION = "1.0.1"
+    val VERSION = "1.0.2"
     val PUBLISHING_TYPE = "AUTOMATIC" // USER_MANAGED or AUTOMATIC
     val SHA_ALGORITHMS = listOf("SHA-256", "SHA-512") // sha256 and sha512 are supported but not mandatory. Only sha1 is mandatory but it is supported by default.
     val DESC = "SRSoftware Configuration: Json-based Implementation"

de.srsoftware.configuration.json/src/main/java/de/srsoftware/configuration/JsonConfig.java

@@ -36,6 +36,15 @@ public class JsonConfig implements Configuration {
 		json = new JSONObject(Files.readString(file.toPath()));
 	}
 
+	/**
+	 * create a JsonConfig instance from a Json object
+	 * @param json the data to use
+	 */
+	public JsonConfig(JSONObject json){
+		file = null;
+		this.json = json;
+	}
+
 	/**
 	 * Create a new JsonConfig using the passed applicationName
 	 * @param applicationName this determines the name of the file, to which data are stored
@@ -148,6 +157,12 @@ public class JsonConfig implements Configuration {
 		}
 	}
 
+	@Override
+	public Optional<JsonConfig> subset(String key) {
+		Optional<JSONObject> json = get(key);
+		return json.map(JsonConfig::new);
+	}
+
 	private Stack<String> toPath(String key) {
 		var parts = key.split("\\.");
 		var path  = new Stack<String>();

de.srsoftware.configuration.json/src/test/java/de/srsoftware/configuration/JsonConfigTest.java

@@ -117,4 +117,19 @@ public class JsonConfigTest {
 		config.drop("hello");
 		assertEquals("{}", config.flat());
 	}
+
+	@Test
+	public void testSubset() throws IOException {
+		config.set("a.a.a", "aaa");
+		config.set("a.a.b", "aab");
+		config.set("a.b.a", "aba");
+		config.set("a.b.b", "abb");
+		assertEquals("{\"a\":{\"a\":{\"a\":\"aaa\",\"b\":\"aab\"},\"b\":{\"a\":\"aba\",\"b\":\"abb\"}}}",config.flat());
+		var subset = config.subset("a");
+		assertTrue(subset.isPresent());
+		assertEquals("{\"a\":{\"a\":\"aaa\",\"b\":\"aab\"},\"b\":{\"a\":\"aba\",\"b\":\"abb\"}}",subset.get().flat());
+		subset = config.subset("a.b");
+		assertTrue(subset.isPresent());
+		assertEquals("{\"a\":\"aba\",\"b\":\"abb\"}",subset.get().flat());
+	}
 }