NullPointerException thrown in SchemaUtils. Fixes #3022

Author: bnasslahsen

springdoc-openapi-starter-common/src/main/java/org/springdoc/core/utils/SchemaUtils.java

@@ -265,7 +265,7 @@ else if (OPENAPI_STRING_TYPE.equals(type)) {
 				schema.setPattern(((Pattern) anno).regexp());
 			}
 		});
-		if (annotatedNotNull(annotations)) {
+		if (schema!=null && annotatedNotNull(annotations)) {
 			String specVersion = schema.getSpecVersion().name();
 			if (!"V30".equals(specVersion)) {
 				schema.setNullable(false);

springdoc-openapi-starter-webmvc-api/src/test/java/test/org/springdoc/api/v31/app244/HelloController.java

@@ -26,14 +26,22 @@
 
 package test.org.springdoc.api.v31.app244;
 
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.enums.ParameterIn;
 import io.swagger.v3.oas.annotations.headers.Header;
+import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.ExampleObject;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import jakarta.validation.Valid;
+import jakarta.validation.constraints.NotNull;
 
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
@@ -64,4 +72,18 @@ public void uploadMultipartWithBody() {
 	void nope() {
 	}
 
+	@PutMapping(value = "/{id}")
+	@Parameter(
+			in = ParameterIn.PATH,
+			name = "id",
+			description = "ID of the user to update",
+			required = true,
+			content = @Content(schema = @Schema(type = "integer")))
+	@Operation(summary = "Update a user by passing the entire object")
+	public void update(
+			@PathVariable("id") @NotNull final String id,
+			@Valid @RequestBody @NotNull final String user,
+			@Parameter(hidden = true) String spec) {
+	}
+
 }

springdoc-openapi-starter-webmvc-api/src/test/resources/results/3.1.0/app244.json

@@ -11,6 +11,45 @@
     }
   ],
   "paths": {
+    "/test/{id}": {
+      "put": {
+        "tags": [
+          "hello-controller"
+        ],
+        "summary": "Update a user by passing the entire object",
+        "operationId": "update",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "description": "ID of the user to update",
+            "required": true,
+            "content": {
+              "*/*": {
+                "schema": {
+                  "type": "integer"
+                }
+              }
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "string"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "OK"
+          }
+        }
+      }
+    },
     "/test": {
       "get": {
         "tags": [