bugfix: undertow has missing request body (#90)

Author: pboos

examples/http/requests.http

@@ -0,0 +1,16 @@
+### POST request
+POST http://localhost:8080/
+Content-Type: application/json
+
+{
+  "name": 1
+}
+
+### GET request
+GET http://localhost:8080/?fromDate=2020-01-01
+
+### GET request (with body)
+GET http://localhost:8080/?fromDate=2020-01-01
+Content-Type: application/json
+
+{}

examples/openapi.yaml

@@ -35,7 +35,7 @@ paths:
       description: Update index
       operationId: postIndex
       requestBody:
-        required: false
+        required: true
         content:
           application/json:
             schema:

spring-boot-starter/spring-boot-starter-web/src/main/java/com/getyourguide/openapi/validation/filter/MultiReadContentCachingRequestWrapper.java

@@ -21,12 +21,12 @@ public MultiReadContentCachingRequestWrapper(HttpServletRequest request, int con
 
     @Override
     public ServletInputStream getInputStream() throws IOException {
-        var inputStream = super.getInputStream();
-        if (inputStream.isFinished()) {
-            return new CachedServletInputStream(getContentAsByteArray());
+        var cachedContent = getContentAsByteArray();
+        if (cachedContent.length > 0) {
+            return new CachedServletInputStream(cachedContent);
         }
 
-        return inputStream;
+        return super.getInputStream();
     }
 
     @Override