[BUG] [Java] Deprecation and serial warnings in JSON.java and ApiException.java when generating using native

[ripdajacker]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Using the native Java generator with a new-enough jackson fails our build because of deprecation warnings in JSON.java:

[WARNING] COMPILATION WARNING : 
[INFO] -------------------------------------------------------------
[WARNING] /redacted/rest/client/ApiException.java:[19,7] [serial] serializable class ApiException has no definition of serialVersionUID
[WARNING] /redacted/rest/client/JSON.java:[21,10] [deprecation] configure(MapperFeature,boolean) in ObjectMapper has been deprecated

The JSON.java problem seems to have been fixed in jersey2 and jersey3 so it's an easy fix.

The serial warnings can be fixed with a one-liner in apException.mustache:

private static final long serialVersionUID = 1L;

The serial warning impacts most of the Java generators except microprofile, which declares a serialVersionUID.

openapi-generator version

7.2.0 but the issue is also on the newest master.

OpenAPI declaration file content or url

{
  "openapi": "3.0.3",
  "info": {
    "version": "1.0.0",
    "description": "Spec to show serial and deprecation warnings",
    "title": "Minimal example"
  },
  "paths": {
    "/whatever": {
      "get": {
        "operationId": "operation",
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "properties": {
                    "field": {
                      "type": "string"
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "model1": {
        "type": "object",
        "properties": {
          "field": {
            "type": "string"
          }
        }
      }
    }
  }
}

Generation Details

Generated using mvn compile.

Steps to reproduce

I have this pom.xml that reproduces it:

<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://maven.apache.org/POM/4.0.0"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.example</groupId>
  <artifactId>openapi-deprecation-serial</artifactId>
  <packaging>jar</packaging>
  <version>1.0.0</version>

  <dependencies>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.16.1</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.datatype</groupId>
      <artifactId>jackson-datatype-jsr310</artifactId>
      <version>2.16.1</version>
    </dependency>
    <dependency>
      <groupId>jakarta.annotation</groupId>
      <artifactId>jakarta.annotation-api</artifactId>
      <version>2.1.1</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.12.1</version>
        <configuration>
          <showWarnings>true</showWarnings>
          <compilerArgs>
            <arg>-Xlint:all</arg>
            <arg>-Xlint:-processing</arg>
            <arg>-Xlint:-options</arg>
            <arg>-Werror</arg>
          </compilerArgs>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.openapitools</groupId>
        <artifactId>openapi-generator-maven-plugin</artifactId>
        <version>7.2.0</version>
        <executions>
          <execution>
            <goals>
              <goal>generate</goal>
            </goals>
            <configuration>
              <apiNameSuffix>Client</apiNameSuffix>
              <inputSpec>${project.basedir}/openapi.json</inputSpec>
              <generatorName>java</generatorName>

              <apiPackage>com.example.rest.client.api</apiPackage>
              <generateApiTests>false</generateApiTests>
              <generateApiDocumentation>false</generateApiDocumentation>

              <modelPackage>com.example.rest</modelPackage>
              <generateModelTests>false</generateModelTests>
              <generateModelDocumentation>false</generateModelDocumentation>

              <configOptions>
                <annotationLibrary>none</annotationLibrary>
                <library>native</library>
                <serializationLibrary>jackson</serializationLibrary>
                <useJakartaEe>true</useJakartaEe>
                <openApiNullable>false</openApiNullable>
                <supportUrlQuery>false</supportUrlQuery>
              </configOptions>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

Related issues/PRs

#17716

Suggest a fix

Fixed in the linked PR.