diff --git a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DBIDRangeRouter.java b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DBIDRangeRouter.java
index f899c72bb..bbbcca37d 100644
--- a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DBIDRangeRouter.java
+++ b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DBIDRangeRouter.java
@@ -18,7 +18,6 @@
  */
 package org.alfresco.solr.tracker;
 
-import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
@@ -111,15 +110,7 @@ public class DBIDRangeRouter implements DocRouter
     @Override
     public Map<String, String> getProperties(QName shardProperty)
     {
-        
-        return new HashMap<String, String>()
-        {
-            private static final long serialVersionUID = -2255464864410358899L;
-            {
-                put(DocRouterFactory.SHARD_RANGE_KEY, startRange + "-" + expandableRange);
-            }
-        };
-        
+        return Map.of(DocRouterFactory.SHARD_RANGE_KEY, startRange + "-" + expandableRange);
     }
     
 }
diff --git a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DateMonthRouter.java b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DateMonthRouter.java
index 32fc43e87..8870f02e6 100644
--- a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DateMonthRouter.java
+++ b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/DateMonthRouter.java
@@ -29,7 +29,6 @@ import java.util.Calendar;
 import java.util.Collections;
 import java.util.Date;
 import java.util.GregorianCalendar;
-import java.util.HashMap;
 import java.util.Map;
 
 /**
@@ -124,21 +123,12 @@ public class DateMonthRouter implements DocRouter
     @Override
     public Map<String, String> getProperties(QName shardProperty)
     {
-        if (shardProperty == null)
-        {
-            return Collections.emptyMap();
-        }
-        else 
-        {
-            return new HashMap<String, String>()
-            {
-                private static final long serialVersionUID = -3201232032535256299L;
-                {
-                    put(DocRouterFactory.SHARD_KEY_KEY, shardProperty.getPrefixString());
-                    put(DocRouterFactory.SHARD_DATE_GROUPING_KEY, String.valueOf(grouping));
-                }
-            };
-        }
+        
+        return (shardProperty == null ? 
+                Collections.emptyMap() : 
+                Map.of(DocRouterFactory.SHARD_KEY_KEY, shardProperty.getPrefixString(),
+                       DocRouterFactory.SHARD_DATE_GROUPING_KEY, String.valueOf(grouping)));
+        
     }
     
 }
diff --git a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/ExplicitShardIdWithDynamicPropertyRouter.java b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/ExplicitShardIdWithDynamicPropertyRouter.java
index ff75a1b3b..383414bcc 100644
--- a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/ExplicitShardIdWithDynamicPropertyRouter.java
+++ b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/ExplicitShardIdWithDynamicPropertyRouter.java
@@ -19,7 +19,6 @@
 package org.alfresco.solr.tracker;
 
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.Map;
 
 import org.alfresco.service.namespace.QName;
@@ -81,20 +80,9 @@ public class ExplicitShardIdWithDynamicPropertyRouter extends ComposableDocRoute
     @Override
     public Map<String, String> getProperties(QName shardProperty)
     {
-        if (shardProperty == null)
-        {
-            return Collections.emptyMap();
-        }
-        else 
-        {
-            return new HashMap<String, String>()
-            {
-                private static final long serialVersionUID = 2142617404056625285L;
-                {
-                    put(DocRouterFactory.SHARD_KEY_KEY, shardProperty.getPrefixString());
-                }
-            };
-        }
+        return (shardProperty == null ? 
+                Collections.emptyMap() : 
+                Map.of(DocRouterFactory.SHARD_KEY_KEY, shardProperty.getPrefixString()));
     }
 
 }
diff --git a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/PropertyRouter.java b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/PropertyRouter.java
index a75eb81c5..c64c59ab0 100644
--- a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/PropertyRouter.java
+++ b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/PropertyRouter.java
@@ -27,7 +27,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -129,21 +128,10 @@ public class PropertyRouter implements DocRouter
     @Override
     public Map<String, String> getProperties(QName shardProperty)
     {
-        if (shardProperty == null)
-        {
-            return Collections.emptyMap();
-        }
-        else 
-        {
-            return new HashMap<String, String>()
-            {
-                private static final long serialVersionUID = -8532652155838845149L;
-                {
-                    put(DocRouterFactory.SHARD_KEY_KEY, shardProperty.getPrefixString());
-                    put(DocRouterFactory.SHARD_REGEX_KEY, propertyRegEx);
-                }
-            };
-        }
+        return (shardProperty == null ? 
+                Collections.emptyMap() : 
+                Map.of(DocRouterFactory.SHARD_KEY_KEY, shardProperty.getPrefixString(),
+                       DocRouterFactory.SHARD_REGEX_KEY, propertyRegEx));
     }
     
 }