diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
index cdd4d96b2e3..ba5a7f99ef5 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
@@ -840,6 +840,10 @@ public class SpringCodegen extends AbstractJavaCodegen
         if (property.isByteArray) {
             model.imports.add("Arrays");
         }
+
+        if (model.getVendorExtensions().containsKey("x-jackson-optional-nullable-helpers")) {
+            model.imports.add("Arrays");
+        }
     }
 
     @Override
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache
index b01a88a6646..e43449ddc0d 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache
@@ -287,7 +287,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
   }{{#vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
@@ -304,9 +304,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
index 20957c36c1f..66eb1760eb7 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
@@ -290,7 +290,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
   }{{#vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
@@ -307,9 +307,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
diff --git a/modules/openapi-generator/src/main/resources/Java/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/pojo.mustache
index b9be16ad565..ce4207b3040 100644
--- a/modules/openapi-generator/src/main/resources/Java/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/pojo.mustache
@@ -263,7 +263,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
   }{{#vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
@@ -280,9 +280,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
index df0b98bfaf7..4226edb1170 100644
--- a/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
@@ -139,7 +139,7 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{^parent}}{{#ha
   }{{#vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
@@ -151,9 +151,7 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{^parent}}{{#ha
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }{{/vendorExtensions.x-jackson-optional-nullable-helpers}}
 
   @Override
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java
index a2bc31cdab7..3ae56d3979a 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -461,7 +461,7 @@ public class EnumTest {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -473,9 +473,7 @@ public class EnumTest {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 9ca1ed06b50..e9acad1a3f0 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -90,7 +90,7 @@ public class HealthCheckResult {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -102,9 +102,7 @@ public class HealthCheckResult {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
index a0cdc543f9c..37d9cc95440 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -585,7 +585,7 @@ public class NullableClass extends HashMap<String, Object> {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -597,9 +597,7 @@ public class NullableClass extends HashMap<String, Object> {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/client/petstore/java/webclient-nulable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java b/samples/client/petstore/java/webclient-nulable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
index 0f1960813ae..a15edcb77f4 100644
--- a/samples/client/petstore/java/webclient-nulable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
+++ b/samples/client/petstore/java/webclient-nulable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
@@ -226,7 +226,7 @@ public class ByteArrayObject {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -238,9 +238,7 @@ public class ByteArrayObject {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java
index a2bc31cdab7..3ae56d3979a 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -461,7 +461,7 @@ public class EnumTest {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -473,9 +473,7 @@ public class EnumTest {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 9ca1ed06b50..e9acad1a3f0 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -90,7 +90,7 @@ public class HealthCheckResult {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -102,9 +102,7 @@ public class HealthCheckResult {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java
index fee8d1fa00e..d11a03e3e31 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -585,7 +585,7 @@ public class NullableClass extends HashMap<String, Object> {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -597,9 +597,7 @@ public class NullableClass extends HashMap<String, Object> {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index bc5318f3f9e..f7badd84904 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -346,7 +346,7 @@ public class AdditionalPropertiesClass {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -358,9 +358,7 @@ public class AdditionalPropertiesClass {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
index eb2ce538d97..eedf71283c3 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
@@ -243,7 +243,7 @@ public class Drawing {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -255,9 +255,7 @@ public class Drawing {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
index 7304f015f29..aee1b8c5343 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -525,7 +525,7 @@ public class EnumTest {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -537,9 +537,7 @@ public class EnumTest {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 71a5e8e2c9f..479a14c09e7 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -95,7 +95,7 @@ public class HealthCheckResult {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -107,9 +107,7 @@ public class HealthCheckResult {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
index 2163e1535b8..de8f62c6667 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -620,7 +620,7 @@ public class NullableClass {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -632,9 +632,7 @@ public class NullableClass {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
index 3644c760842..fceb70ecf5f 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
@@ -451,7 +451,7 @@ public class User {
   }
 
   private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && a.get().getClass().isArray() ? Arrays.equals((T[])a.get(), (T[])b.get()) : Objects.equals(a.get(), b.get()));
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
   }
 
   @Override
@@ -463,9 +463,7 @@ public class User {
     if (a == null) {
       return 1;
     }
-    return a.isPresent()
-      ? (a.get().getClass().isArray() ? Arrays.hashCode((T[])a.get()) : Objects.hashCode(a.get()))
-      : 31;
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
   }
 
   @Override