[Spring] fix nullable map properties (#16524)

* fix map in spring generators

* fix nullable map in spring generators

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java

@@ -55,7 +55,7 @@ public class AdditionalPropertiesClass {
 
   private Object anytype1;
 
-  private JsonNullable<Object> anytype2 = JsonNullable.undefined();
+  private JsonNullable<Object> anytype2 = JsonNullable.<Object>undefined();
 
   private Object anytype3;
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ContainerDefaultValue.java

@@ -28,16 +28,16 @@ import javax.annotation.Generated;
 public class ContainerDefaultValue {
 
   @Valid
-  private JsonNullable<List<String>> nullableArray = JsonNullable.undefined();
+  private JsonNullable<List<String>> nullableArray = JsonNullable.<List<String>>undefined();
 
   @Valid
-  private JsonNullable<List<String>> nullableRequiredArray = JsonNullable.undefined();
+  private JsonNullable<List<String>> nullableRequiredArray = JsonNullable.<List<String>>undefined();
 
   @Valid
   private List<String> requiredArray = new ArrayList<>();
 
   @Valid
-  private JsonNullable<List<String>> nullableArrayWithDefault = JsonNullable.undefined();
+  private JsonNullable<List<String>> nullableArrayWithDefault = JsonNullable.<List<String>>undefined();
 
   public ContainerDefaultValue() {
     super();

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NullableMapProperty.java

@@ -0,0 +1,109 @@
+package org.openapitools.model;
+
+import java.net.URI;
+import java.util.Objects;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import io.swagger.annotations.ApiModel;
+import io.swagger.annotations.ApiModelProperty;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import org.openapitools.jackson.nullable.JsonNullable;
+import java.util.NoSuchElementException;
+import org.openapitools.jackson.nullable.JsonNullable;
+import java.time.OffsetDateTime;
+import javax.validation.Valid;
+import javax.validation.constraints.*;
+
+
+import java.util.*;
+import javax.annotation.Generated;
+
+/**
+ * NullableMapProperty
+ */
+
+@Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
+public class NullableMapProperty {
+
+  @Valid
+  private JsonNullable<Map<String, String>> languageValues = JsonNullable.<Map<String, String>>undefined();
+
+  public NullableMapProperty languageValues(Map<String, String> languageValues) {
+    this.languageValues = JsonNullable.of(languageValues);
+    return this;
+  }
+
+  public NullableMapProperty putLanguageValuesItem(String key, String languageValuesItem) {
+    if (this.languageValues == null || !this.languageValues.isPresent()) {
+      this.languageValues = JsonNullable.of(new HashMap<>());
+    }
+    this.languageValues.get().put(key, languageValuesItem);
+    return this;
+  }
+
+  /**
+   * Get languageValues
+   * @return languageValues
+  */
+  
+  @ApiModelProperty(value = "")
+  @JsonProperty("languageValues")
+  public JsonNullable<Map<String, String>> getLanguageValues() {
+    return languageValues;
+  }
+
+  public void setLanguageValues(JsonNullable<Map<String, String>> languageValues) {
+    this.languageValues = languageValues;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    NullableMapProperty nullableMapProperty = (NullableMapProperty) o;
+    return equalsNullable(this.languageValues, nullableMapProperty.languageValues);
+  }
+
+  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
+    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(hashCodeNullable(languageValues));
+  }
+
+  private static <T> int hashCodeNullable(JsonNullable<T> a) {
+    if (a == null) {
+      return 1;
+    }
+    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class NullableMapProperty {\n");
+    sb.append("    languageValues: ").append(toIndentedString(languageValues)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+}
+

samples/server/petstore/springboot-useoptional/src/main/resources/openapi.yaml

@@ -2186,6 +2186,14 @@ components:
         property name with spaces:
           type: string
       type: object
+    NullableMapProperty:
+      properties:
+        languageValues:
+          additionalProperties:
+            type: string
+          nullable: true
+          type: object
+      type: object
     updatePetWithForm_request:
       properties:
         name: