Generate the Java code to create an OpenAPI document

generateCode.java

//usr/bin/env jbang "$0" "$@" ; exit $?

//DEPS org.openapitools.empoa:empoa-swagger-core:1.1.0
//DEPS org.openapitools.empoa:empoa-javapoet:1.1.0
//DEPS io.swagger.parser.v3:swagger-parser:2.0.20
//DEPS org.slf4j:slf4j-simple:1.7.30

import org.eclipse.microprofile.openapi.models.OpenAPI;
import org.openapitools.empoa.javapoet.JavaFileConverter;
import org.openapitools.empoa.swagger.core.internal.SwAdapter;

import com.squareup.javapoet.JavaFile;

import io.swagger.parser.OpenAPIParser;
import io.swagger.v3.parser.core.models.ParseOptions;
import io.swagger.v3.parser.core.models.SwaggerParseResult;

public class generateCode {

    public static void main(String... args) {
        if(args.length == 0) {
            System.err.println("Expecting arguments:");
            System.err.println("   - Path to the OpenAPI specification Json or Yaml file (mandatory)");
            System.err.println("   - Class name (if omitted \"SpecMain\" is used)");
            System.err.println("   - Package name (if omitted \"tmp\" is used)");
            System.exit(1);
        } else {
            String packageName = (args.length > 1) ? args[2] : "tmp";
            String className = (args.length > 0) ? args[1] : "Spec";
            String specLocation =  args[0];
            System.out.println("// Generated based on spec: " + specLocation);
            final OpenAPIParser openApiParser = new OpenAPIParser();
            final ParseOptions options = new ParseOptions();
            final SwaggerParseResult parserResult = openApiParser.readLocation(specLocation, null, options);

            OpenAPI openAPI = SwAdapter.toOpenAPI(parserResult.getOpenAPI());
            JavaFile javaFile = JavaFileConverter.createOpenAPI(openAPI, packageName, className);
            System.out.println(javaFile.toString());
        }
    }
}

See blog post: Generate the Java code to create an OpenAPI document