diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index 17eae742c6b..48ee109c972 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -2226,7 +2226,12 @@ public class DefaultCodegen implements CodegenConfig {
                 if (StringUtils.isNotBlank(requestBody.get$ref())) {
                     requestBody = openAPI.getComponents().getRequestBodies().get(getSimpleRef(requestBody.get$ref()));
                 }
-                bodyParam = fromRequestBody(requestBody, schemas, imports);
+
+                String bodyParameterName = "";
+                if (op.vendorExtensions != null && op.vendorExtensions.containsKey("x-codegen-body-parameter-name")) {
+                    bodyParameterName = (String) op.vendorExtensions.get("x-codegen-body-parameter-name");
+                }
+                bodyParam = fromRequestBody(requestBody, schemas, imports, bodyParameterName);
                 bodyParam.description = requestBody.getDescription();
                 postProcessParameter(bodyParam);
 
@@ -4172,7 +4177,7 @@ public class DefaultCodegen implements CodegenConfig {
         return codegenParameter;
     }
 
-    public CodegenParameter fromRequestBody(RequestBody body, Map<String, Schema> schemas, Set<String> imports) {
+    public CodegenParameter fromRequestBody(RequestBody body, Map<String, Schema> schemas, Set<String> imports, String bodyParameterName) {
         if (body == null) {
             LOGGER.error("body in fromRequestBody cannot be null!");
         }
@@ -4197,9 +4202,14 @@ public class DefaultCodegen implements CodegenConfig {
                 schema.setName(name);
                 codegenModel = fromModel(name, schema, schemas);
             }
+
             if (codegenModel != null && !codegenModel.emptyVars) {
-                codegenParameter.baseName = codegenModel.classname;
-                codegenParameter.paramName = toParamName(codegenModel.classname);
+                if (StringUtils.isEmpty(bodyParameterName)) {
+                    codegenParameter.baseName = codegenModel.classname;
+                } else {
+                    codegenParameter.baseName = bodyParameterName;
+                }
+                codegenParameter.paramName = toParamName(codegenParameter.baseName);
                 codegenParameter.baseType = codegenModel.classname;
                 codegenParameter.dataType = getTypeDeclaration(codegenModel.classname);
                 codegenParameter.description = codegenModel.description;
@@ -4249,8 +4259,13 @@ public class DefaultCodegen implements CodegenConfig {
                 mostInnerItem = innerCp;
                 innerCp = innerCp.items;
             }
-            codegenParameter.baseName = mostInnerItem.complexType;
-            codegenParameter.paramName = toArrayModelParamName(mostInnerItem.complexType);
+
+            if (StringUtils.isEmpty(bodyParameterName)) {
+                codegenParameter.baseName = mostInnerItem.complexType;
+            } else {
+                codegenParameter.baseName = bodyParameterName;
+            }
+            codegenParameter.paramName = toArrayModelParamName(codegenParameter.baseName);
             codegenParameter.items = codegenProperty.items;
             codegenParameter.dataType = getTypeDeclaration(arraySchema);
             codegenParameter.baseType = getSchemaType(arraySchema);
@@ -4273,8 +4288,12 @@ public class DefaultCodegen implements CodegenConfig {
             // only support 1-dimension map only
             imports.add(codegenProperty.baseType);
 
-            codegenParameter.baseName = "request_body";
-            codegenParameter.paramName = toParamName("request_body");
+            if (StringUtils.isEmpty(bodyParameterName)) {
+                codegenParameter.baseName = "request_body";
+            } else {
+                codegenParameter.baseName = bodyParameterName;
+            }
+            codegenParameter.paramName = toParamName(codegenParameter.baseName);
             codegenParameter.items = codegenProperty.items;
             codegenParameter.dataType = getTypeDeclaration(inner);
             codegenParameter.baseType = getSchemaType(inner);
@@ -4286,10 +4305,10 @@ public class DefaultCodegen implements CodegenConfig {
             // HTTP request body is primitive type (e.g. integer, string, etc)
             CodegenProperty codegenProperty = fromProperty("PRIMITIVE_REQUEST_BODY", schema);
             if (codegenProperty != null) {
-                if (schema.getExtensions() != null && schema.getExtensions().containsKey("x-codegen-body-parameter-name")) {
-                    codegenParameter.baseName = (String) schema.getExtensions().get("x-codegen-body-parameter-name");
+                if (StringUtils.isEmpty(bodyParameterName)) {
+                    codegenParameter.baseName = "body";  // default to body
                 } else {
-                    codegenParameter.baseName = "body"; // default to body
+                    codegenParameter.baseName = bodyParameterName;
                 }
                 codegenParameter.isPrimitiveType = true;
                 codegenParameter.baseType = codegenProperty.baseType;
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
index a5267caf175..1d1814d0a20 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
@@ -145,7 +145,7 @@ public class JavaClientCodegenTest {
         RequestBody body1 = new RequestBody();
         body1.setDescription("A list of ids");
         body1.setContent(new Content().addMediaType("application/json", new MediaType().schema(new ArraySchema().items(new StringSchema()))));
-        CodegenParameter codegenParameter1 = codegen.fromRequestBody(body1 , new HashMap<String, Schema>(), new HashSet<String>());
+        CodegenParameter codegenParameter1 = codegen.fromRequestBody(body1 , new HashMap<String, Schema>(), new HashSet<String>(), null);
         Assert.assertEquals(codegenParameter1.description, "A list of ids");
         Assert.assertEquals(codegenParameter1.dataType, "List<String>");
         Assert.assertEquals(codegenParameter1.baseType, "List");
@@ -153,7 +153,7 @@ public class JavaClientCodegenTest {
         RequestBody body2 = new RequestBody();
         body2.setDescription("A list of list of values");
         body2.setContent(new Content().addMediaType("application/json", new MediaType().schema(new ArraySchema().items(new ArraySchema().items(new IntegerSchema())))));
-        CodegenParameter codegenParameter2 = codegen.fromRequestBody(body2 , new HashMap<String, Schema>(), new HashSet<String>());
+        CodegenParameter codegenParameter2 = codegen.fromRequestBody(body2 , new HashMap<String, Schema>(), new HashSet<String>(), null);
         Assert.assertEquals(codegenParameter2.description, "A list of list of values");
         Assert.assertEquals(codegenParameter2.dataType, "List<List<Integer>>");
         Assert.assertEquals(codegenParameter2.baseType, "List");
@@ -165,7 +165,7 @@ public class JavaClientCodegenTest {
         point.addProperties("message", new StringSchema());
         point.addProperties("x", new IntegerSchema().format(SchemaTypeUtil.INTEGER32_FORMAT));
         point.addProperties("y", new IntegerSchema().format(SchemaTypeUtil.INTEGER32_FORMAT));
-        CodegenParameter codegenParameter3 = codegen.fromRequestBody(body3 , Collections.<String, Schema>singletonMap("Point", point), new HashSet<String>());
+        CodegenParameter codegenParameter3 = codegen.fromRequestBody(body3 , Collections.<String, Schema>singletonMap("Point", point), new HashSet<String>(), null);
         Assert.assertEquals(codegenParameter3.description, "A list of points");
         Assert.assertEquals(codegenParameter3.dataType, "List<Point>");
         Assert.assertEquals(codegenParameter3.baseType, "List");