diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache
index 86fb8dd899c..ede8e5b9566 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/api.mustache
@@ -346,12 +346,17 @@ public class {{classname}} {
     localVarRequestBuilder.header("Accept", "{{#hasProduces}}{{#produces}}{{mediaType}}{{^-last}}, {{/-last}}{{/produces}}{{/hasProduces}}{{#hasProduces}}{{^produces}}application/json{{/produces}}{{/hasProduces}}{{^hasProduces}}application/json{{/hasProduces}}");
 
     {{#bodyParam}}
+    {{#isString}}
+    localVarRequestBuilder.method("{{httpMethod}}", HttpRequest.BodyPublishers.ofString({{paramName}}));
+    {{/isString}}
+    {{^isString}}
     try {
       byte[] localVarPostBody = memberVarObjectMapper.writeValueAsBytes({{paramName}});
       localVarRequestBuilder.method("{{httpMethod}}", HttpRequest.BodyPublishers.ofByteArray(localVarPostBody));
     } catch (IOException e) {
       throw new ApiException(e);
     }
+    {{/isString}}
     {{/bodyParam}}
     {{^bodyParam}}
     localVarRequestBuilder.method("{{httpMethod}}", HttpRequest.BodyPublishers.noBody());
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/FakeApi.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/FakeApi.java
index b600572f511..8f6c3721de8 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/FakeApi.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/FakeApi.java
@@ -519,12 +519,7 @@ public class FakeApi {
     localVarRequestBuilder.header("Content-Type", "application/json");
     localVarRequestBuilder.header("Accept", "*/*");
 
-    try {
-      byte[] localVarPostBody = memberVarObjectMapper.writeValueAsBytes(body);
-      localVarRequestBuilder.method("POST", HttpRequest.BodyPublishers.ofByteArray(localVarPostBody));
-    } catch (IOException e) {
-      throw new ApiException(e);
-    }
+    localVarRequestBuilder.method("POST", HttpRequest.BodyPublishers.ofString(body));
     if (memberVarReadTimeout != null) {
       localVarRequestBuilder.timeout(memberVarReadTimeout);
     }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java
index 665df72be2f..20ce3349193 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java
@@ -445,12 +445,7 @@ public class FakeApi {
     localVarRequestBuilder.header("Content-Type", "application/json");
     localVarRequestBuilder.header("Accept", "*/*");
 
-    try {
-      byte[] localVarPostBody = memberVarObjectMapper.writeValueAsBytes(body);
-      localVarRequestBuilder.method("POST", HttpRequest.BodyPublishers.ofByteArray(localVarPostBody));
-    } catch (IOException e) {
-      throw new ApiException(e);
-    }
+    localVarRequestBuilder.method("POST", HttpRequest.BodyPublishers.ofString(body));
     if (memberVarReadTimeout != null) {
       localVarRequestBuilder.timeout(memberVarReadTimeout);
     }