Polish contribution

See gh-31248

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/lookup/AbstractRoutingDataSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -61,7 +61,7 @@ public abstract class AbstractRoutingDataSource extends AbstractDataSource imple
 
 	/**
 	 * Specify the map of target DataSources, with the lookup key as key.
-	 * The mapped value can either be a corresponding {@link javax.sql.DataSource}
+	 * <p>The mapped value can either be a corresponding {@link javax.sql.DataSource}
 	 * instance or a data source name String (to be resolved via a
 	 * {@link #setDataSourceLookup DataSourceLookup}).
 	 * <p>The key can be of arbitrary type; this class implements the
@@ -114,15 +114,23 @@ public abstract class AbstractRoutingDataSource extends AbstractDataSource imple
 	}
 
 
+	/**
+	 * Delegates to {@link #initialize()}.
+	 */
 	@Override
 	public void afterPropertiesSet() {
 		initialize();
 	}
 
 	/**
-	 * Synchronizes targetDataSources to resolvedDataSources
-	 * and defaultTargetDataSource to resolvedDefaultDataSource.
-	 * @throws IllegalArgumentException in case of targetDataSources is null
+	 * Initialize the internal state of this {@code AbstractRoutingDataSource}
+	 * by resolving the configured target DataSources.
+	 * @throws IllegalArgumentException if the target DataSources have not been configured
+	 * @since 6.1
+	 * @see #setTargetDataSources(Map)
+	 * @see #setDefaultTargetDataSource(Object)
+	 * @see #getResolvedDataSources()
+	 * @see #getResolvedDefaultDataSource()
 	 */
 	public void initialize() {
 		if (this.targetDataSources == null) {