Install Java 21

Install Docker Desktop

Start Mock server docker on port 8888

docker run -it --rm --name wm -p 8888:8080 -v "<project location>\spring-cloud-gateway-mvc-demo\tools\wiremock:/home/wiremock" rodolpheche/wiremock  --verbose

For example,
docker run -it --rm --name wm -p 8888:8080 -v "C:\Users\<user>\dev\Git_work\github\spring-cloud-gateway-mvc-demo\tools\wiremock:/home/wiremock" rodolpheche/wiremock  --verbose

Look at the file generated-requests.http under tools directory in order to execute api requests from the IDE(Intellij)

For running Spring gateway MVC, we need the following jars. Take a look at pom.xml

<dependencies>
  ...
  <!-- Spring gateway MVC -->
  <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-gateway-mvc</artifactId>
  </dependency>

  <!-- Apache rest client - used for dispatching requests to targets -->
  <dependency>
      <groupId>org.apache.httpcomponents.client5</groupId>
      <artifactId>httpclient5</artifactId>
  </dependency>
  ...
</dependencies>

server:
  port: 8090
  servlet:
    context-path: /api/v1

spring:
  cloud:
    gateway:
      mvc:
        http-client:
          type: autodetect
          connect-timeout: 30s
          read-timeout: 30s
  threads:
    virtual:
      enabled: true

#application parameters
app:
  gateway:
    remote-servers:
      target: http://localhost:8888

First route by defining RouteFunction Bean.

See file HelloWorldRoutingConfig.java

In order to check it, start Mock server at port 8888 and return a response for GET request of /basic/hello You should call GET http://localhost:8090/api/v1/basic/hello (See generated-requests.http).

We want to do the following steps:

• Add header to the request with a fixed value(addRequestHeader).
• Add header to the request with a dynamic value(addDynamicRequestHeader).
• Log the response status received from the target server(logResponseStatus).

See file CustomFunctionsRoutingConfig.java.

By calling the GET request http://localhost:8090/api/v1/custom/filter/java/hello, you could see two additional headers at the request received in the Wiremock server.

We want new filter which can add new header with Random UUID value.
Function addDynamicRequestHeaderFromSupplier is defined in class CustomBeforeFilterFunctions.java. See file spring.factories. We define there a FilterSupplier which is loaded to the available filters.

By calling the GET request http://localhost:8090/api/v1/custom/filter/configuration/hello, you should see the header 'X-my-header-from-configuration' at the request received in the Wiremock server.

We want new predicate which can get list of paths to match. MultiPath is the name of the predicate.
Function multiPath is defined in class CustomGatewayRequestPredicates.java. See file spring.factories. We define there a PredicateSupplier which is loaded to the available predicates.

By calling the GET requests: http://localhost:8090/api/v1/custom/filter/configuration/helloPredicate1 or http://localhost:8090/api/v1/custom/filter/configuration/helloPredicate2, you should get a response from Wiremock server.