ProGuard Jackson problem

Aztek.java

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;

@Getter
@Setter
@AllArgsConstructor
@ToString
public class Aztek extends CarModel {

	private int year;

	@JsonCreator
	public Aztek(@JsonProperty("name") String name, @JsonProperty("year") int year) {
		this.year = year;
	}

	@Override
	@ToString.Include
	public String getName() {
		return "Ugly";
	}

}

build.gradle

buildscript {
	repositories {
		mavenCentral()
	}
	dependencies {
		classpath 'com.guardsquare:proguard-gradle:7.6.1'
	}
}

plugins {
	id 'java'
	id "io.freefair.lombok" version "8.12.1"
}

repositories {
	mavenCentral()
}

def appMainClass = 'rizzo.test.JacksonPolymorphicSerialization'

java {
	toolchain {
		languageVersion = JavaLanguageVersion.of(17)
	}
}

jar {
	duplicatesStrategy = 'exclude'
	
	manifest {
		attributes 'Main-Class': "${appMainClass}"
	}
	
	from {
		configurations.runtimeClasspath.collect { it.isDirectory() ? it : zipTree(it) }
	}
}

dependencies {
	implementation group: 'com.fasterxml.jackson.core', name: 'jackson-databind', version: '2.18.2'
	implementation group: 'com.fasterxml.jackson.core', name: 'jackson-annotations', version: '2.18.2'
}

task proguard(type: proguard.gradle.ProGuardTask) {
	dependsOn classes
	
	verbose
	printmapping "${buildDir}/proguard-mapping.txt"

	injars "${buildDir}/classes/java/main"
	outjars "${buildDir}/classes/obfuscated/"

	libraryjars "${System.getProperty('java.home')}/jmods/java.base.jmod", jarfilter: '!**.jar', filter: '!module-info.class'
	libraryjars "${System.getProperty('java.home')}/jmods/java.logging.jmod", jarfilter: '!**.jar', filter: '!module-info.class'
	libraryjars "${System.getProperty('java.home')}/jmods/java.desktop.jmod", jarfilter: '!**.jar', filter: '!module-info.class'
	libraryjars "${System.getProperty('java.home')}/jmods/java.xml.jmod", jarfilter: '!**.jar', filter: '!module-info.class'
	libraryjars "${System.getProperty('java.home')}/jmods/java.sql.jmod", jarfilter: '!**.jar', filter: '!module-info.class'

	// This will contain the app dependencies.
	libraryjars sourceSets.main.compileClasspath

	keepdirectories

	// Preserve getters and setters
	keepclassmembers 'class * { \
		** get*(); \
		void set*(***); \
	}'

	// Keep the main class entry point.
	keep "public class ${appMainClass} { \
			public static void main(java.lang.String[]); \
		 }"

	// This helps produce useful stack traces (see https://www.guardsquare.com/manual/configuration/examples#stacktrace)
	renamesourcefileattribute 'SourceFile'
	keepattributes '*Annotation*,EnclosingMethod,SourceFile,LineNumberTable'

	doLast {
		delete "${buildDir}/classes/java/main"
		copy {
			from "${buildDir}/classes/obfuscated/"
			into "${buildDir}/classes/java/main"
		}
		
	}
}

CarModel.java

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
import com.fasterxml.jackson.annotation.JsonTypeInfo.Id;

@JsonAutoDetect(fieldVisibility = Visibility.ANY)
@JsonTypeInfo(use = Id.NAME, include = As.PROPERTY, property = "type")
@JsonSubTypes({
		@JsonSubTypes.Type(value = Corvette.class),
		@JsonSubTypes.Type(value = Aztek.class)
})
public abstract class CarModel {

	public abstract String getName();
	public abstract int getYear();
}

Corvette.java

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.ToString;

@Getter
@AllArgsConstructor
@ToString
public class Corvette extends CarModel {

	private int year;

	@JsonCreator
	public Corvette(@JsonProperty("name") String name, @JsonProperty("year") int year) {
		this.year = year;
	}

	@Override
	@ToString.Include
	public String getName() {
		return "Corvette";
	}

}

Inventory.java

import java.util.List;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

import lombok.Getter;

@Getter
public class Inventory {

	private String owner;
	private List<CarModel> cars;

	@JsonCreator
	public Inventory(@JsonProperty("owner") String owner, @JsonProperty("cars") List<CarModel> cars) {
		this.owner = owner;
		this.cars = cars;
	}

	@Override
	public String toString() {
		StringBuilder builder = new StringBuilder("Inventory [");
		builder.append("owner=")
			.append(owner)
			.append(", cars=<");

		System.out.println("First cars element is of type " + cars.get(0).getClass());

		cars.forEach(car -> builder.append(car).append(", "));
		builder.append(">");

		builder.append("]");
		return builder.toString();
	}
}

JacksonPolymorphicSerialization.java

import static com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES;
import static com.fasterxml.jackson.databind.MapperFeature.DEFAULT_VIEW_INCLUSION;

import java.util.List;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JacksonException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectReader;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.fasterxml.jackson.databind.json.JsonMapper;

public class JacksonPolymorphicSerialization {

	private final static ObjectMapper JSONMapper =
			JsonMapper.builder()
			.configure(DEFAULT_VIEW_INCLUSION, false)
			.configure(FAIL_ON_UNKNOWN_PROPERTIES, false)
			.serializationInclusion(Include.NON_ABSENT)
			.build();
	private static final ObjectReader JSONReader = JSONMapper.readerFor(Inventory.class);
	private static final ObjectWriter JSONWriter = JSONMapper.writerFor(Inventory.class).withDefaultPrettyPrinter();


	public static void main(String[] args) throws JacksonException {
		Corvette corvette = new Corvette(1963);
		Aztek aztek = new Aztek(2003);
		Inventory inventory = new Inventory("Jay Leno", List.of(corvette, aztek));

		String json = JSONWriter.writeValueAsString(inventory);
		System.out.println("Serialized form:\n" + json);

		System.out.println();

		inventory = JSONReader.readValue(json);
		System.out.println("Deserialized object: " + inventory);
	}
}