MCR-3650 Refactor MCRConfigurableInstanceHelper into multiple classes

mycore-base/src/main/java/org/mycore/common/config/MCRConfiguration2.java

@@ -32,6 +32,8 @@
 import java.util.stream.Stream;
 
 import org.mycore.common.MCRClassTools;
+import org.mycore.common.config.MCRInstanceConfiguration.Option;
+import org.mycore.common.config.MCRInstanceConfiguration.Options;
 import org.mycore.common.function.MCRTriConsumer;
 
 /**
@@ -131,11 +133,11 @@ public static Map<String, String> getSubPropertiesMap(String propertyPrefix) {
      * @throws MCRConfigurationException if the class can not be loaded or instantiated
      */
     public static <S> Optional<S> getInstanceOf(Class<S> superClass, String name) throws MCRConfigurationException {
-        return getInstanceOf(superClass, name, MCRConfigurableInstanceHelper.NO_OPTIONS);
+        return getInstanceOf(superClass, name, Options.NONE);
     }
 
     private static <S> Optional<S> getInstanceOf(Class<S> superClass, String name,
-        Set<MCRConfigurableInstanceHelper.Option> options) {
+        Set<Option> options) {
         if (MCRConfigurableInstanceHelper.isSingleton(superClass)) {
             return getSingleInstanceOf(superClass, name, options);
         } else {
@@ -153,7 +155,7 @@ private static <S> Optional<S> getInstanceOf(Class<S> superClass, String name,
      * or the configuration property is not set
      */
     public static <S> S getInstanceOfOrThrow(Class<S> superClass, String name) throws MCRConfigurationException {
-        return getInstanceOf(superClass, name, MCRConfigurableInstanceHelper.ADD_IMPLICIT_CLASS_PROPERTIES)
+        return getInstanceOf(superClass, name, Options.IMPLICIT)
             .orElseThrow(() -> createConfigurationException(name));
     }
 
@@ -167,11 +169,11 @@ public static <S> S getInstanceOfOrThrow(Class<S> superClass, String name) throw
      * @throws MCRConfigurationException if the class can not be loaded or instantiated
      */
     public static <S> Optional<S> getSingleInstanceOf(Class<S> superClass, String name) {
-        return getSingleInstanceOf(superClass, name, MCRConfigurableInstanceHelper.NO_OPTIONS);
+        return getSingleInstanceOf(superClass, name, Options.NONE);
     }
 
     private static <S> Optional<S> getSingleInstanceOf(Class<S> superClass, String name,
-        Set<MCRConfigurableInstanceHelper.Option> options) {
+        Set<Option> options) {
         return getString(name)
             .map(className -> new ConfigSingletonKey(name, className))
             .map(key -> (S) instanceHolder.computeIfAbsent(key,
@@ -189,7 +191,7 @@ private static <S> Optional<S> getSingleInstanceOf(Class<S> superClass, String n
      * or the configuration property is not set
      */
     public static <S> S getSingleInstanceOfOrThrow(Class<S> superClass, String name) {
-        return getSingleInstanceOf(superClass, name, MCRConfigurableInstanceHelper.ADD_IMPLICIT_CLASS_PROPERTIES)
+        return getSingleInstanceOf(superClass, name, Options.IMPLICIT)
             .orElseThrow(() -> createConfigurationException(name));
     }
 

mycore-base/src/main/java/org/mycore/common/config/MCRConfigurationException.java

@@ -18,10 +18,10 @@
 
 package org.mycore.common.config;
 
-import org.mycore.common.MCRException;
-
 import java.io.Serial;
 
+import org.mycore.common.MCRException;
+
 /**
  * Instances of this class represent an exception thrown because of an error in the MyCoRe configuration. Normally this
  * will be the case when a configuration property that is required is not set or has an illegal value.

mycore-base/src/main/java/org/mycore/common/config/MCRInstanceConfiguration.java

@@ -22,6 +22,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * Represents an extract of properties (typically {@link MCRConfiguration2#getPropertiesMap()}) used to
@@ -389,6 +390,9 @@ public Map<String, MCRInstanceConfiguration> nestedConfigurationMap() {
      * @return the nested configuration map
      */
     public Map<String, MCRInstanceConfiguration> nestedConfigurationMap(String commonPrefix) {
+        if (commonPrefix.isEmpty()) {
+            return nestedConfigurationMap();
+        }
         String commonSuffixWithDelimiter = commonPrefix + ".";
         Map<String, MCRInstanceConfiguration> nestedConfigurationMap = new HashMap<>();
         for (Map.Entry<String, String> entry : properties().entrySet()) {
@@ -444,4 +448,28 @@ public String toString() {
             "#fullProperties=" + fullProperties.size() + "}";
     }
 
+    public enum Option {
+
+        /**
+         * If a class name is required to be in the configuration properties (for example, because of usage of
+         * {@link MCRConfiguration2#getInstanceOfOrThrow(Class, String)} or because of an annotation with
+         * <code>required=true</code>) and the expected super class is a final class (meaning, if the property
+         * containing the class name is required to exist and can only have the class name of that final class),
+         * assume that that property exists (if it doesn't).
+         */
+        IMPLICIT
+
+    }
+
+    public static final class Options {
+
+        public static final Set<Option> NONE = Set.of();
+
+        public static final Set<Option> IMPLICIT = Set.of(Option.IMPLICIT);
+
+        private Options() {
+        }
+
+    }
+
 }

mycore-base/src/main/java/org/mycore/common/config/annotation/MCRProperty.java

@@ -67,7 +67,7 @@
      * @return The {@link MCRSentinel} for the configured property.
      */
     MCRSentinel sentinel() default @MCRSentinel(enabled = false);
-    
+
     /**
      * @return The order in which the annotated fields or methods are processed. The higher the value, the later the
      * field or method is processed. All fields are processed first, then all methods are processed.

mycore-base/src/main/java/org/mycore/common/config/annotation/MCRPropertyList.java

@@ -61,7 +61,7 @@
      * The default property must be absolute, e.g. <code>MCR.Foo.Bar</code>.
      */
     String defaultName() default "";
-    
+
     /**
      * @return The {@link MCRSentinel} for the configured properties.
      */

mycore-base/src/main/java/org/mycore/common/config/annotation/MCRRawProperties.java

@@ -18,14 +18,14 @@
 
 package org.mycore.common.config.annotation;
 
-import org.mycore.common.config.MCRConfigurationException;
-
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Inherited;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import org.mycore.common.config.MCRConfigurationException;
+
 /**
  * This annotation is used to mark fields or methods that should be set to or called with
  * a map of string values from the configuration properties.