tessl/maven-com-google-auto-value--auto-value

Generated immutable value classes for Java 8+ using annotation processing

—

Pending

Overview

Eval results

Files

Serialization

Name: tessl/maven-com-google-auto-value--auto-value
Author: tessl

The @SerializableAutoValue annotation generates serializable implementations for AutoValue classes that contain non-serializable fields like Optional, ImmutableList, or other modern Java types.

Basic Serializable AutoValue

@SerializableAutoValue
@AutoValue
public abstract class Person implements Serializable {
  public abstract String name();
  public abstract Optional<String> email();
  public abstract ImmutableList<String> hobbies();
  
  public static Person create(String name, Optional<String> email, ImmutableList<String> hobbies) {
    return new AutoValue_Person(name, email, hobbies);
  }
}

The generated code automatically handles serialization of:

Optional<T> fields
ImmutableList<T>, ImmutableSet<T>, ImmutableMap<K,V>
Other common non-serializable types

Usage Example

Person person = Person.create(
    "Alice",
    Optional.of("alice@example.com"),
    ImmutableList.of("reading", "coding", "hiking"));

// Serialize to bytes
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(person);
byte[] serialized = baos.toByteArray();

// Deserialize from bytes
ByteArrayInputStream bais = new ByteArrayInputStream(serialized);
ObjectInputStream ois = new ObjectInputStream(bais);
Person deserialized = (Person) ois.readObject();

System.out.println(person.equals(deserialized)); // true

Supported Types

The serialization extension automatically handles these non-serializable types:

@SerializableAutoValue
@AutoValue
public abstract class TypesExample implements Serializable {
  // Optional types
  public abstract Optional<String> optionalString();
  public abstract OptionalInt optionalInt();
  public abstract OptionalLong optionalLong();
  public abstract OptionalDouble optionalDouble();
  
  // Guava Immutable Collections
  public abstract ImmutableList<String> list();
  public abstract ImmutableSet<Integer> set();
  public abstract ImmutableMap<String, Object> map();
  public abstract ImmutableMultimap<String, String> multimap();
  public abstract ImmutableTable<String, String, Object> table();
  
  // Other Guava types
  public abstract ImmutableRangeSet<Integer> rangeSet();
  public abstract ImmutableRangeMap<Integer, String> rangeMap();
  
  public static TypesExample create(
      Optional<String> optionalString,
      OptionalInt optionalInt,
      OptionalLong optionalLong, 
      OptionalDouble optionalDouble,
      ImmutableList<String> list,
      ImmutableSet<Integer> set,
      ImmutableMap<String, Object> map,
      ImmutableMultimap<String, String> multimap,
      ImmutableTable<String, String, Object> table,
      ImmutableRangeSet<Integer> rangeSet,
      ImmutableRangeMap<Integer, String> rangeMap) {
    return new AutoValue_TypesExample(
        optionalString, optionalInt, optionalLong, optionalDouble,
        list, set, map, multimap, table, rangeSet, rangeMap);
  }
}

Nested Serializable AutoValue

SerializableAutoValue works with nested AutoValue objects:

@SerializableAutoValue
@AutoValue
public abstract class Address implements Serializable {
  public abstract String street();
  public abstract String city();
  public abstract Optional<String> zipCode();
  
  public static Address create(String street, String city, Optional<String> zipCode) {
    return new AutoValue_Address(street, city, zipCode);
  }
}

@SerializableAutoValue
@AutoValue  
public abstract class Company implements Serializable {
  public abstract String name();
  public abstract Address headquarters();
  public abstract ImmutableList<Address> offices();
  public abstract ImmutableMap<String, Optional<String>> contacts();
  
  public static Company create(
      String name,
      Address headquarters,
      ImmutableList<Address> offices,
      ImmutableMap<String, Optional<String>> contacts) {
    return new AutoValue_Company(name, headquarters, offices, contacts);
  }
}

Custom Serializer Extensions

Create custom serializers for types not supported by default:

// Custom type that needs serialization support
public class CustomType {
  private final String data;
  
  public CustomType(String data) {
    this.data = data;
  }
  
  public String getData() {
    return data;
  }
}

// Custom serializer extension
public class CustomTypeSerializerExtension implements SerializerExtension {
  @Override
  public Optional<Serializer> getSerializer(
      TypeMirror typeMirror, 
      SerializerFactory factory) {
    if (isCustomType(typeMirror)) {
      return Optional.of(new CustomTypeSerializer());
    }
    return Optional.empty();
  }
  
  private boolean isCustomType(TypeMirror type) {
    return type.toString().equals(CustomType.class.getName());
  }
  
  private static class CustomTypeSerializer implements Serializer {
    @Override
    public TypeMirror proxyFieldType() {
      return getTypeMirror(String.class);
    }
    
    @Override
    public CodeBlock toProxy(CodeBlock expression) {
      return CodeBlock.of("$L.getData()", expression);
    }
    
    @Override
    public CodeBlock fromProxy(CodeBlock expression) {
      return CodeBlock.of("new $T($L)", CustomType.class, expression);
    }
  }
}

Register the extension in META-INF/services/com.google.auto.value.extension.serializable.serializer.interfaces.SerializerExtension.

Serialization with Builders

SerializableAutoValue works seamlessly with builders:

@SerializableAutoValue
@AutoValue
public abstract class Configuration implements Serializable {
  public abstract String host();
  public abstract Optional<Integer> port();
  public abstract ImmutableSet<String> features();
  public abstract ImmutableMap<String, String> properties();
  
  public static Builder builder() {
    return new AutoValue_Configuration.Builder()
        .features(ImmutableSet.of())
        .properties(ImmutableMap.of());
  }
  
  @AutoValue.Builder
  public abstract static class Builder {
    public abstract Builder host(String host);
    public abstract Builder port(int port);
    public abstract Builder features(Iterable<String> features);
    public abstract Builder properties(Map<String, String> properties);
    
    public abstract Builder addFeature(String feature);
    public abstract Builder putProperty(String key, String value);
    
    public abstract Configuration build();
  }
}

Serialization works with builder-created objects:

Configuration config = Configuration.builder()
    .host("localhost")
    .port(8080)
    .addFeature("ssl")
    .addFeature("compression")
    .putProperty("timeout", "5000")
    .build();

// Serialize and deserialize
byte[] serialized = serialize(config);
Configuration deserialized = deserialize(serialized);
System.out.println(config.equals(deserialized)); // true

Generic SerializableAutoValue

Serialization supports generic types:

@SerializableAutoValue
@AutoValue
public abstract class Container<T> implements Serializable {
  public abstract T value();
  public abstract Optional<String> label();
  public abstract ImmutableList<T> alternatives();
  
  public static <T> Container<T> create(
      T value,
      Optional<String> label,
      ImmutableList<T> alternatives) {
    return new AutoValue_Container<>(value, label, alternatives);
  }
}

Usage with serialization:

Container<String> stringContainer = Container.create(
    "main value",
    Optional.of("primary"),
    ImmutableList.of("alt1", "alt2"));

// Serialization preserves generic type information
byte[] serialized = serialize(stringContainer);
Container<String> deserialized = deserialize(serialized);

Error Handling

SerializableAutoValue provides clear errors for unsupported types:

@SerializableAutoValue
@AutoValue
public abstract class UnsupportedExample implements Serializable {
  // This will cause a compilation error
  public abstract NonSerializableCustomType customField(); // ERROR: No serializer found
  
  public static UnsupportedExample create(NonSerializableCustomType customField) {
    return new AutoValue_UnsupportedExample(customField);
  }
}

The error message will indicate which type needs a custom serializer.

Serialization Performance

The generated serialization code is optimized:

Uses direct field access (no reflection at runtime)
Minimal object creation during serialization
Efficient proxy objects for complex types
Lazy initialization of serialization metadata

Version Compatibility

Handle serialization version compatibility:

@SerializableAutoValue
@AutoValue
public abstract class VersionedData implements Serializable {
  private static final long serialVersionUID = 1L;
  
  public abstract String name();
  public abstract Optional<String> description();
  public abstract ImmutableList<String> tags();
  
  // Method to handle version compatibility
  private Object readResolve() {
    // Custom logic for handling old versions
    return this;
  }
  
  public static VersionedData create(String name, Optional<String> description, ImmutableList<String> tags) {
    return new AutoValue_VersionedData(name, description, tags);
  }
}

Integration with Other Extensions

SerializableAutoValue can be combined with other extensions:

@SerializableAutoValue
@AutoValue
public abstract class CachedSerializableData implements Serializable {
  public abstract String data();
  public abstract Optional<ImmutableList<Integer>> values();
  
  @Memoized
  public String processedData() {
    return data().toUpperCase().trim();
  }
  
  @Memoized
  @Override
  public abstract String toString();
  
  public static CachedSerializableData create(String data, Optional<ImmutableList<Integer>> values) {
    return new AutoValue_CachedSerializableData(data, values);
  }
}

The memoized fields are properly handled during serialization/deserialization.

Restrictions

The AutoValue class must implement Serializable
All custom types in properties must either be serializable or have custom serializers
Generic type parameters must be serializable at runtime
Builder classes are not automatically serializable (only the built objects are)

Install with Tessl CLI

npx tessl i tessl/maven-com-google-auto-value--auto-value

docs

annotation-generation.md

standalone-builders.md

tagged-unions.md

value-classes.md

tile.json