🐛 Fixing some issues with threading and NPE (#5107)

* 🐛 Fixing some issues with threading and NPE

After running Sonar on the master branch, some major analysis
opportunities were displayed.

This fixes the use of SimpleDateFormat stored as static fields.
SimpleDateFormat is not thread-safe, and may retain data across threads.
While there's no indicator that this has caused any issues (these are
mostly used for example code), we should follow these best practices.

This also fixes a handful of NPE and other minor issues such as
comparing Boolean.TRUE to strings and no wrapping some closeables in
try-with-resources.

* [cli] Unit test GenerateBatch custom deserialization helper

* Quiet batch mode in sonar.yml

* Suppress unnecessary warnings (ThreadLocals in static fields)

modules/openapi-generator-cli/src/test/resources/batch/common/jaxrs-datelib-j8.json

@@ -0,0 +1,7 @@
+{
+  "serializableModel": true,
+  "withXml": true,
+  "dateLibrary": "java8",
+  "java8": true,
+  "useBeanValidation": true
+}

modules/openapi-generator-cli/src/test/resources/batch/common/jaxrs-datelib-j8.yaml

@@ -0,0 +1,6 @@
+---
+serializableModel: true
+withXml: true
+dateLibrary: java8
+java8: true
+useBeanValidation: true

modules/openapi-generator-cli/src/test/resources/batch/jaxrs-datelib-j8-json-include.yaml

@@ -0,0 +1,8 @@
+---
+"!include": common/jaxrs-datelib-j8.json
+generatorName: jaxrs-jersey
+inputSpec: batch/specs/petstore.yaml
+outputDir: outputDir
+additionalProperties:
+  hideGenerationTimestamp: true
+  serverPort: '8082'

modules/openapi-generator-cli/src/test/resources/batch/jaxrs-datelib-j8-yaml-include.json

@@ -0,0 +1,10 @@
+{
+  "!include": "common/jaxrs-datelib-j8.yaml",
+  "generatorName": "jaxrs-jersey",
+  "inputSpec": "batch/specs/petstore.yaml",
+  "outputDir": "outputDir",
+  "additionalProperties": {
+    "hideGenerationTimestamp": true,
+    "serverPort": "8082"
+  }
+}

modules/openapi-generator-cli/src/test/resources/batch/jaxrs-datelib-j8.json

@@ -0,0 +1,10 @@
+{
+  "!include": "common/jaxrs-datelib-j8.json",
+  "generatorName": "jaxrs-jersey",
+  "inputSpec": "batch/specs/petstore.yaml",
+  "outputDir": "outputDir",
+  "additionalProperties": {
+    "hideGenerationTimestamp": true,
+    "serverPort": "8082"
+  }
+}

modules/openapi-generator-cli/src/test/resources/batch/jaxrs-datelib-j8.yaml

@@ -0,0 +1,8 @@
+---
+"!include": common/jaxrs-datelib-j8.yaml
+generatorName: jaxrs-jersey
+inputSpec: batch/specs/petstore.yaml
+outputDir: outputDir
+additionalProperties:
+  hideGenerationTimestamp: true
+  serverPort: '8082'

modules/openapi-generator-cli/src/test/resources/batch/specs/petstore.yaml

@@ -0,0 +1,111 @@
+openapi: "3.0.0"
+info:
+  version: 1.0.0
+  title: Swagger Petstore
+  license:
+    name: MIT
+servers:
+  - url: http://petstore.swagger.io/v1
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      operationId: listPets
+      tags:
+        - pets
+      parameters:
+        - name: limit
+          in: query
+          description: How many items to return at one time (max 100)
+          required: false
+          schema:
+            type: integer
+            format: int32
+      responses:
+        '200':
+          description: A paged array of pets
+          headers:
+            x-next:
+              description: A link to the next page of responses
+              schema:
+                type: string
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pets"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+    post:
+      summary: Create a pet
+      operationId: createPets
+      tags:
+        - pets
+      responses:
+        '201':
+          description: Null response
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+  /pets/{petId}:
+    get:
+      summary: Info for a specific pet
+      operationId: showPetById
+      tags:
+        - pets
+      parameters:
+        - name: petId
+          in: path
+          required: true
+          description: The id of the pet to retrieve
+          schema:
+            type: string
+      responses:
+        '200':
+          description: Expected response to a valid request
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pet"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+components:
+  schemas:
+    Pet:
+      type: object
+      required:
+        - id
+        - name
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string
+    Pets:
+      type: array
+      items:
+        $ref: "#/components/schemas/Pet"
+    Error:
+      type: object
+      required:
+        - code
+        - message
+      properties:
+        code:
+          type: integer
+          format: int32
+        message:
+          type: string