javadoc fixes

Signed-off-by: Attila Mészáros <a_meszaros@apple.com>

Author: csviri

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/loader/ConfigLoader.java

@@ -150,7 +150,7 @@ public ConfigLoader(
 
   /**
    * Returns a {@link Consumer} that applies every operator-level property found in the {@link
-   * ConfigProvider} to the given {@link ConfigurationServiceOverrider}. Returns {@code null} when
+   * ConfigProvider} to the given {@link ConfigurationServiceOverrider}. Returns no-op consumer when
    * no binding has a matching value, preserving the previous behavior.
    */
   public Consumer<ConfigurationServiceOverrider> applyConfigs() {

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/loader/DefaultConfigProvider.java

@@ -19,6 +19,25 @@
 import java.util.Optional;
 import java.util.function.Function;
 
+/**
+ * A {@link ConfigProvider} that resolves configuration values from environment variables and Java
+ * system properties.
+ *
+ * <p>For a given key, lookup proceeds as follows:
+ *
+ * <ol>
+ *   <li>The key is converted to an environment variable name by replacing dots and hyphens with
+ *       underscores and converting to upper case (e.g. {@code josdk.cache-sync.timeout} → {@code
+ *       JOSDK_CACHE_SYNC_TIMEOUT}). If an environment variable with that name is set, its value is
+ *       used.
+ *   <li>If no matching environment variable is found, the key is looked up as a Java system
+ *       property (via {@link System#getProperty(String)}) using the original key name.
+ * </ol>
+ *
+ * <p>Environment variables take precedence over system properties when both are set. Supported
+ * value types are: {@link String}, {@link Boolean}, {@link Integer}, {@link Long}, {@link Double},
+ * and {@link java.time.Duration} (ISO-8601 format, e.g. {@code PT30S}).
+ */
 public class DefaultConfigProvider implements ConfigProvider {
 
   private final Function<String, String> envLookup;