Fixes NPE in springdoc-openapi-javadoc for nested parameters with a depth > 1

springdoc-openapi-common/src/main/java/org/springdoc/core/AbstractRequestService.java

@@ -729,7 +729,7 @@ private String getParamJavadoc(JavadocProvider javadocProvider, MethodParameter
 		if (delegatingMethodParameter.isParameterObject()) {
 			String fieldName;
 			if (StringUtils.isNotEmpty(pName) && pName.contains(DOT))
-				fieldName = StringUtils.substringAfter(pName, DOT);
+				fieldName = StringUtils.substringAfterLast(pName, DOT);
 			else
 				fieldName = pName;
 			Field field = FieldUtils.getDeclaredField(((DelegatingMethodParameter) methodParameter).getExecutable().getDeclaringClass(), fieldName, true);

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/ConcreteSubclassFromGeneric.java

@@ -0,0 +1,13 @@
+package test.org.springdoc.api.app166;
+
+public class ConcreteSubclassFromGeneric extends SimpleGeneric<MyData> {
+
+    /**
+     * Return the top name
+     */
+    private String topName;
+
+    public String getTopName() {
+        return topName;
+    }
+}

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/HelloController.java

@@ -0,0 +1,48 @@
+/*
+ *
+ *  *
+ *  *  *
+ *  *  *  * Copyright 2019-2022 the original author or authors.
+ *  *  *  *
+ *  *  *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  *  *  * you may not use this file except in compliance with the License.
+ *  *  *  * You may obtain a copy of the License at
+ *  *  *  *
+ *  *  *  *      https://www.apache.org/licenses/LICENSE-2.0
+ *  *  *  *
+ *  *  *  * Unless required by applicable law or agreed to in writing, software
+ *  *  *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  *  *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  *  *  * See the License for the specific language governing permissions and
+ *  *  *  * limitations under the License.
+ *  *  *
+ *  *
+ *
+ */
+
+package test.org.springdoc.api.app166;
+
+
+import org.springdoc.api.annotations.ParameterObject;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HelloController {
+	@GetMapping("/nested")
+	public ResponseEntity<String> nested(@ParameterObject final SimpleOuterClass filter) {
+		return new ResponseEntity<>("{\"Say\": \"Hello\"}", HttpStatus.OK);
+	}
+
+	@GetMapping( "/nestedTypeErasureGeneric")
+	public ResponseEntity<String> nestedTypeErasureGeneric( @ParameterObject final SimpleGeneric<MyData> filter) {
+		return new ResponseEntity<>("{\"Say\": \"Hello\"}", HttpStatus.OK);
+	}
+
+	@GetMapping( "/nestedReifiableGeneric")
+	public ResponseEntity<String> nestedReifiableGeneric( @ParameterObject final ConcreteSubclassFromGeneric filter) {
+		return new ResponseEntity<>("{\"Say\": \"Hello\"}", HttpStatus.OK);
+	}
+}

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/MyData.java

@@ -0,0 +1,22 @@
+package test.org.springdoc.api.app166;
+
+public class MyData {
+
+    /**
+     * Returns the first name
+     */
+    private String firstName;
+
+    /**
+     * Returns the max number
+     */
+    private Integer maxNumber;
+
+    public Integer getMaxNumber() {
+        return maxNumber;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+}

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/SimpleGeneric.java

@@ -0,0 +1,22 @@
+package test.org.springdoc.api.app166;
+
+public class SimpleGeneric<T> {
+
+    /**
+     * Returns name
+     */
+    private String name;
+
+    /**
+     * Returns the generic child
+     */
+    private T child;
+
+    public T getChild() {
+        return child;
+    }
+
+    public String getName() {
+        return name;
+    }
+}

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/SimpleInnerClass.java

@@ -0,0 +1,31 @@
+package test.org.springdoc.api.app166;
+
+public class SimpleInnerClass {
+
+    /**
+     * Returns the inner inner class
+     */
+    private SimpleInnerInnerClass innerInnerClass;
+
+    /**
+     * Returns the boolean name
+     */
+    private Boolean name;
+
+    /**
+     * Returns the max number
+     */
+    private Integer maxNumber;
+
+    public Integer getMaxNumber() {
+        return maxNumber;
+    }
+
+    public Boolean getName() {
+        return name;
+    }
+
+    public SimpleInnerInnerClass getInnerInnerClass() {
+        return innerInnerClass;
+    }
+}

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/SimpleInnerInnerClass.java

@@ -0,0 +1,21 @@
+package test.org.springdoc.api.app166;
+
+public class SimpleInnerInnerClass {
+    /**
+     * Returns the name of the inner inner class
+     */
+    Boolean name;
+
+    /**
+     * Returns the maxNumber of the inner inner class
+     */
+    private Integer maxNumber;
+
+    public Integer getMaxNumber() {
+        return maxNumber;
+    }
+
+    public Boolean getName() {
+        return name;
+    }
+}

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/SimpleOuterClass.java

@@ -0,0 +1,22 @@
+package test.org.springdoc.api.app166;
+
+public class SimpleOuterClass {
+
+    /**
+     * Returns the name of the outer class
+     */
+    private String name;
+
+    /**
+     * Returns the inner class
+     */
+    private SimpleInnerClass innerClass;
+
+    public String getName() {
+        return name;
+    }
+
+    public SimpleInnerClass getInnerClass() {
+        return innerClass;
+    }
+}

springdoc-openapi-javadoc/src/test/java/test/org/springdoc/api/app166/SpringDocApp166Test.java

@@ -0,0 +1,35 @@
+/*
+ *
+ *  * Copyright 2019-2020 the original author or authors.
+ *  *
+ *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  * you may not use this file except in compliance with the License.
+ *  * You may obtain a copy of the License at
+ *  *
+ *  *      https://www.apache.org/licenses/LICENSE-2.0
+ *  *
+ *  * Unless required by applicable law or agreed to in writing, software
+ *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  * See the License for the specific language governing permissions and
+ *  * limitations under the License.
+ *
+ */
+
+package test.org.springdoc.api.app166;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import test.org.springdoc.api.AbstractSpringDocTest;
+
+/**
+ * The type Spring doc app 165 test.
+ */
+public class SpringDocApp166Test extends AbstractSpringDocTest {
+
+    /**
+     * The type Spring doc test app.
+     */
+    @SpringBootApplication
+    static class SpringDocTestApp {
+    }
+}

springdoc-openapi-javadoc/src/test/resources/results/app166.json

@@ -0,0 +1,122 @@
+{
+  "openapi": "3.0.1",
+  "info": { "title": "OpenAPI definition", "version": "v0" },
+  "servers": [
+    { "url": "http://localhost", "description": "Generated server url" }
+  ],
+  "paths": {
+    "/nested": {
+      "get": {
+        "tags": ["hello-controller"],
+        "operationId": "nested",
+        "parameters": [
+          {
+            "name": "name",
+            "in": "query",
+            "description": "Returns the name of the outer class",
+            "required": false,
+            "schema": { "type": "string" }
+          },
+          {
+            "name": "innerClass.innerInnerClass.name",
+            "in": "query",
+            "description": "Returns the name of the inner inner class",
+            "required": false,
+            "schema": { "type": "boolean" }
+          },
+          {
+            "name": "innerClass.innerInnerClass.maxNumber",
+            "in": "query",
+            "description": "Returns the maxNumber of the inner inner class",
+            "required": false,
+            "schema": { "type": "integer", "format": "int32" }
+          },
+          {
+            "name": "innerClass.name",
+            "in": "query",
+            "description": "Returns the boolean name",
+            "required": false,
+            "schema": { "type": "boolean" }
+          },
+          {
+            "name": "innerClass.maxNumber",
+            "in": "query",
+            "description": "Returns the max number",
+            "required": false,
+            "schema": { "type": "integer", "format": "int32" }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": { "*/*": { "schema": { "type": "string" } } }
+          }
+        }
+      }
+    },
+    "/nestedTypeErasureGeneric": {
+      "get": {
+        "tags": ["hello-controller"],
+        "operationId": "nestedTypeErasureGeneric",
+        "parameters": [
+          {
+            "name": "name",
+            "in": "query",
+            "description": "Returns name",
+            "required": false,
+            "schema": { "type": "string" }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": { "*/*": { "schema": { "type": "string" } } }
+          }
+        }
+      }
+    },
+    "/nestedReifiableGeneric": {
+      "get": {
+        "tags": ["hello-controller"],
+        "operationId": "nestedReifiableGeneric",
+        "parameters": [
+          {
+            "name": "topName",
+            "in": "query",
+            "description": "Return the top name",
+            "required": false,
+            "schema": { "type": "string" }
+          },
+          {
+            "name": "name",
+            "in": "query",
+            "description": "Returns name",
+            "required": false,
+            "schema": { "type": "string" }
+          },
+          {
+            "name": "child.firstName",
+            "in": "query",
+            "description": "Returns the first name",
+            "required": false,
+            "schema": { "type": "string" }
+          },
+          {
+            "name": "child.maxNumber",
+            "in": "query",
+            "description": "Returns the max number",
+            "required": false,
+            "schema": { "type": "integer", "format": "int32" }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": { "*/*": { "schema": { "type": "string" } } }
+          }
+        }
+      }
+    }
+  },
+  "components": {}
+}