Build APIs using OpenAPI

<!-- Generate OpenAPI specifications at build-->
<plugin>
  <groupId>io.swagger.core.v3</groupId>
  <artifactId>swagger-maven-plugin</artifactId>
  <version>2.2.48</version>
  <configuration>
    <resourcePackages>
      <resourcePackage>org.datapith.cdk4j.examples.springCloud</resourcePackage>
    </resourcePackages>
    <outputPath>${basedir}/target/api-specs</outputPath>
    <outputFileName>swagger</outputFileName>
    <outputFormat>JSONANDYAML</outputFormat>
    <prettyPrint>true</prettyPrint>
  </configuration>
  <executions>
    <execution>
      <phase>compile</phase>
      <goals>
        <goal>resolve</goal>
      </goals>
    </execution>
  </executions>
</plugin>

<!-- Annotation for open-api specs generation -->
<dependency>
  <groupId>javax.ws.rs</groupId>
  <artifactId>javax.ws.rs-api</artifactId>
  <version>2.1.1</version>
</dependency>
<dependency>
  <groupId>io.swagger.core.v3</groupId>
  <artifactId>swagger-annotations</artifactId>
  <version>2.2.42</version>
  <scope>compile</scope>
</dependency>

  @Bean(name = UPPERCASE_FUNCTION_NAME)
  @POST
  @Path("/upper")
  @Operation(
      description = "TODO",
      extensions = {
          // The`x-amazon-apigateway-integration` is an OpenAPI extension used in AWS API Gateway to define how a REST or HTTP API method
          // connects to backend services like Lambda, HTTP endpoints, or other AWS services.
          @Extension(
              name = "x-amazon-apigateway-integration",
              properties = {
                  @ExtensionProperty(
                      name = "uri",
                      /*
                       * defines the custom integration of the method with a Lambda function. This field does not identify the specific
                       * Lambda function, but instead has a placeholder string (“uppercase”) that will be replaced with the correct
                       * function name during the launch.
                       * Make sure that this name matches the name/id of the lambda in the AWS cdk stack
                       */
                      value = UPPERCASE_FUNCTION_NAME
                  ),
                  @ExtensionProperty(
                      name = "passthroughBehavior",
                      value = "when_no_match"
                  ),
                  @ExtensionProperty(
                      name = "type",
                      value = "aws_proxy"
                  ),
                  @ExtensionProperty(
                      name = "httpMethod",
                      value = "POST"
                  )
              }
          )
      }
  )
  @ApiResponses(
      value = {
          @ApiResponse(responseCode = "204", description = "Successfully processed Incident Event"),
          @ApiResponse(
              responseCode = "400",
              description = "Bad request. For example when a mandatory argument is missing."),
          @ApiResponse(responseCode = "404", description = "Incident not found"),
          @ApiResponse(
              responseCode = "500",
              description =
                  "Internal server error: Status change not possible or error when sending a message")
      })
  public Function<String, String> uppercase() {
    return String::toUpperCase;
  }

// Define Lambda function routing to Spring cloud function uppercase
Function uppercase = Function.Builder.create(this, "uppercase")
    .functionName("uppercase")
    // GraalVM specific Runtime
    .runtime(Runtime.JAVA_25)
    .timeout(Duration.seconds(30))
    .memorySize(512)
    .handler("org.springframework.cloud.function.adapter.aws.FunctionInvoker::handleRequest")
    .code(Code.fromAsset("./target/cdk4j-examples-aws.jar"))
    .environment(
        Map.of(
            "MAIN_CLASS", Cdk4jSpringCloudApplication.class.getName(),
            "spring_cloud_function_definition", UppercaseFunction.UPPERCASE_FUNCTION_NAME
        )
    )
    .build();

// Load API specs as generated by maven build
final Asset apiDefinitionAsset = new Asset(this, "cdk4j-example-api", AssetProps.builder().path("target/api-specs/swagger.json").build());

// Create API integration between API specs and Lambda function
ApiIntegration uppercaseApiIntegration = ApiIntegration.builder()
    // Make sure this name matches the placeholder name in open api specs
    .id(UppercaseFunction.UPPERCASE_FUNCTION_NAME)
    // The Lambda function to associate with the API method in the OpenAPI file matched by id.
    .existingLambdaObj(uppercase)
    .build();

// Define REST API for function
new OpenApiGatewayToLambda(this, "cdk4j-example-api", OpenApiGatewayToLambdaProps.builder()
    .apiDefinitionAsset(apiDefinitionAsset)
    .apiIntegrations(Collections.singletonList(uppercaseApiIntegration))
    .build());