Elsa Serialization

Elsa is serialization framework for Java. It offers more features and data serialized by Elsa are much smaller. Elsa was developed as part of MapDB (formerly JDBM) since 2010, and was recently refactored into separate project.

Elsa was developed as drop-in replacement for ObjectOutputStream serialization (Java Serialization). It offers following features:

• Compact size of serialized data
  • 10-50x smaller data size compared to Java Serialization
  • Class Catalog (class names, field names) can be stored externaly to reduce data usage
  • Serialization is slower than Java Serialization, deserialization is faster
• 99% compatible with Java Serialization
  • Classes should implement Serializable interface (option to disable this)
  • Handles Externalizable, objectReplace and other tricks
  • It falls-back into OOS if advanced features are detected

• Cyclic Graph handling

  • Optional deduplication using Object.equals
  • Options to tune reference tracking overhead to various graph sizes

• Plugable serializer model

  • Your own serializer can be integrated into Object Graph traversal
  • User defined singletons
  • Singleton resolvers etc...
• Long term storage on mind
  • Storage format is well specified
  • Option to rename classes or fields with backward compatibility