fixes #86 add tutorial for json object as query parameter

content/en/tutorial/rest/openapi/_index.md

@@ -9,3 +9,14 @@ aliases: []
 toc: false
 draft: false
 ---
+
+This section contains tutorials based on the OpenAPI 3.0 specifications. As most of our users have switched to the OpenAPI 3.0, we are going to add more tutorials here instead of [Swagger 2.0][] section. 
+
+* [OpenAPI 3.0](/tutorial/rest/openapi/)
+   + [OpenAPI 3.0 Petstore](/tutorial/rest/openapi/petstore/)
+   + [JSON Query Parameter](/tutorial/rest/openapi/parameter-serialization/json-query-param/)
+   + [Microservices Aggregate Pattern](/tutorial/rest/openapi/ms-aggregate/)
+   + [Microservices Branch Pattern](/tutorial/rest/openapi/ms-branch/)
+
+
+[Swagger 2.0]: /tutorial/rest/swagger/

content/en/tutorial/rest/openapi/parameter-serialization/_index.md

@@ -0,0 +1,29 @@
+---
+title: "Parameter Serialization"
+date: 2019-05-13T15:16:43-04:00
+description: ""
+categories: []
+keywords: []
+slug: ""
+aliases: []
+toc: false
+draft: false
+reviewed: true
+---
+
+For most users, their use cases are straightforward in term of parameters; however, we do have some users have advanced use cases with [parameter serialization][]. 
+
+OpenAPI 3.0 supports arrays and objects in operation parameters (path, query, header, and cookie) and lets you specify how these parameters should be serialized. The serialization method is defined by the `style` and `explode` keywords:
+
+* `style` defines how multiple values are delimited. Possible styles depend on the parameter location – path, query, header or cookie.
+
+* `explode` (true/false) specifies whether arrays and objects should generate separate parameters for each array item or object property.
+
+OpenAPI serialization rules are based on a subset of URI template patterns defined by RFC 6570. Tool implementers can use existing URI template libraries to handle the serialization, as explained below.
+
+In this tutorial, we are going to include some examples so that users can learn from them. 
+
+* [JSON query parameter](/tutorial/rest/openapi/parameter-serialization/json-query-param/)
+
+[parameter serialization]: https://swagger.io/docs/specification/serialization/
+

content/en/tutorial/rest/openapi/parameter-serialization/json-query-param.md

@@ -0,0 +1,89 @@
+---
+title: "JSON Query Parameter"
+date: 2019-05-13T15:51:43-04:00
+description: ""
+categories: []
+keywords: []
+slug: ""
+aliases: []
+toc: false
+draft: false
+reviewed: true
+---
+
+`style` and `explode` cover the most common serialization methods, but not all. For more complex scenarios (for example, a JSON-formatted object in the query string), you can use the content keyword and specify the media type that defines the serialization format. Or you can use schema to define the JSON object. For more information, please visit [schema vs content][].
+
+In this tutorial, we are going to create a service with one endpoint that accepts a JSON object as a query parameter. The use case is provided by one of our contributors @Dasanko in this [issue](https://github.com/networknt/light-rest-4j/issues/67)
+
+To generate the example project, we need to create a specification file named openapi.yaml and a config.json for the light-codegen. 
+
+You can find these two files and a README.md in the [model-config][] repository. The following is the specification. 
+
+```
+openapi: 3.0.0
+
+info:
+  title: TestProject
+  version: 1.0.0
+
+servers:
+  - url: 'https://localhost:8443/api'
+
+paths:
+  /testEndPoint:
+    get:
+      parameters:
+        - in: query
+          name: TestObject
+          schema:
+            $ref: '#/components/schemas/TestObject'
+      responses:
+        '200':
+          description: History something something
+          content:
+            application/json:
+              schema:
+                type: string
+
+components:
+  schemas:
+    TestObject:
+      type: object
+      properties:
+        testProperty:
+          type: string
+```
+
+To generate the project with light-codegen. 
+
+```
+cd ~/networknt
+rm -rf light-example-4j/rest/openapi/json-query-param
+java -jar light-codegen/codegen-cli/target/codegen-cli.jar -f openapi -o light-example-4j/rest/openapi/json-query-param -m model-config/rest/openapi/json-query-param/openapi.yaml -c model-config/rest/openapi/json-query-param/config.json
+```
+
+If you don't want to generate the project yourself, you can check the generated project in the [light-example-4j][]
+
+Now you can start the server in the light-example-4j folder.
+
+```
+cd ~/networknt/light-example-4j/rest/openapi/json-query-param
+mvn clean install exec:exec
+```
+
+Once the server is up and running, you can issue the following commands from another terminal.
+
+```
+curl -k -X GET https://localhost:8443/api/testEndPoint?TestObject={testProperty=testing}
+curl -k -X GET https://localhost:8443/api/testEndPoint?TestObject=testProperty,testing
+curl -k -X GET https://localhost:8443/api/testEndPoint?testProperty=testing
+curl -k -X GET https://localhost:8443/api/testEndPoint?TestObject[testProperty]=testing
+```
+
+All the above commands should pass the light-rest-4j OpenAPI validator without any error. As there is no business logic implemented in the example application, the response body is empty with a response code of 200. 
+
+If you are interested, you can add the business logic to get the input parameter and return something meaningful. 
+
+[schema vs content]: https://swagger.io/docs/specification/describing-parameters/#schema-vs-content
+[model-config]: https://github.com/networknt/model-config/tree/master/rest/openapi/json-query-param
+[light-example-4j]: https://github.com/networknt/light-example-4j/tree/master/rest/openapi/json-query-param

content/en/tutorial/rest/swagger/_index.md

@@ -8,4 +8,14 @@ slug: ""
 aliases: []
 toc: false
 draft: false
+reviewed: true
 ---
+
+This section contains tutorials based on the Swagger 2.0 specifications. As most of our users have switched to the [OpenAPI 3.0][], we are still in a process to migrate everything from Swagger 2.0 to [OpenAPI 3.0][]. It is likely these tutorials will be changed in the future. 
+
+* [Swagger 2.0](/tutorial/rest/swagger/)
+   + [Swagger 2.0 Petstore](/tutorial/rest/swagger/petstore/)
+   + [Restful Database Access](/tutorial/rest/swagger/database/)
+   + [Microservices Chain Pattern](/tutorial/rest/swagger/ms-chain/)
+
+[OpenAPI 3.0]: /tutorial/rest/openapi/