compilation error in POM, due to use of openApi usage for code generation

Question

So I am using a openApi code generator. (All this goes for Swagger codegen too, same error)

I have created a maven project in eclipse, and I have a POM which looks like this...

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.test.api.openapi</groupId>
  <artifactId>test-openapi-codegen</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>test-openapi-codegen</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
  </properties>
  
  <build>
   <plugins>
    <plugin>
     <groupId>org.openapitools</groupId>
     <artifactId>openapi-generator-maven-plugin</artifactId>
     <version>4.3.1</version>
     <executions>
        <execution>
            <goals>
                <goal>generate</goal>
            </goals>
            <configuration>
                <inputSpec>${project.basedir}/src/main/resources/openAPI.yaml</inputSpec>
                <generatorName>java</generatorName>
                <apiPackage>com.test.openapi.codegen.demo.api</apiPackage>
                <modelPackage>com.test.openapi.codegen.demo.model</modelPackage>
                <invokerPackage>com.test.openapi.codegen.demo</invokerPackage>
                <configOptions>
                <sourceFolder>src/java/</sourceFolder>
                </configOptions>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.openapitools</groupId>
      <artifactId>openapi-generator-maven-plugin</artifactId>
      <version>4.3.1</version>
      <scope>provided</scope>
    </dependency> 
  </dependencies>
</project>

So this POM is taking a YAML file to generate the JAVA code, YAML file act as a architecture/structure file for the code that is to be generated.

Here is a link : [https://openapi-generator.tech/docs/plugins/][1] --> The Plugin that I used is mentioned in the link.

So when I am doing a mvn clean compile, the code is being generated in the output folder mentioned in tag -> src/java/generated-code -> like this. also a POM is being generated for that generated code, but with the above command "mvn clean compile" I am getting below error, saying that A LOT" of packages are missing. READ NEXT TWO LINES.

HERE IS A CATCH, I CHECKED THE POM THAT WAS GENERATED AND DEPENDENCIES WERE RIGHLTY PRESENT IN THE POM AND I TESTED IT AS WELL USING "MVN COMPILE" AND BUILD WAS SUCCESSFUL FOR THAT POM

 Changes detected - recompiling the module!
    [INFO] Compiling 43 source files to T:\Perforce\testStream\openapi-codegen\target\classes
    [INFO] -------------------------------------------------------------
    [ERROR] COMPILATION ERROR :
    [INFO] -------------------------------------------------------------
    [ERROR] T:/Perforce/testStream/openapi-codegen/target/generated-sources/openapi/src/java/com/test/openapi/codegen/demo/model/ProvisioningBatch.java:[18,23] package com.google.gson does not exist

What am I doing wrong? I have described in the best possible way.

Answer 1

I fixed the problem by adding the missing dependencies, but I do not thinks its the best approach, better use a cli jar for the need.

Download jar from maven central, openapi-codegen-cli.jar and its a runnable jar and use the arguments as per req.

It will generate a code from the YAML, and then you can use the generated POM to mvn clean install or anything you want