XML and Java: Serialization APIs

According to JavaSoft's Object Serialization documentation:

"Object Serialization supports the encoding of objects, and the objects reachable from them, into a stream of bytes; and it supports the complementary reconstruction of the object graph from the stream. Serialization is used for lightweight persistence and for communication via sockets or Remote Method Invocation (RMI)."

Serialization is often used to save the state of an application as a binary representation of all the objects with their current values. Unfortunately, serialized components are fragile, being sensitive to changes in the classes used to produce them. Therefore XML APIs that handle Java serialization provide a useful alternative: a human readable (and editable) persistent state format. This enables you to keep data in a form you can examine if software fails (as opposed to keeping data in objects that can only be accessed via methods).

Koala Object Markup Language (KOML)

URL: http://www.inria.fr/koala/XML/serialization/

Technical Notes: http://www.inria.fr/koala/XML/serialization/komltech.html

API Documentation: http://www.inria.fr/koala/XML/serialization/komlapi/index.html

Koala XML serialization provides an easy way to serialize and deserialize Java Objects in an XML document. (Koala is the French acronym for toolkit for advanced software environment.) This is a 100% pure Java solution with support for SAX. KOML defines a DTD and Namespace.

Koala XML Serialization uses the Java serialization in a two-step process:

1. Serialize all objects with the class java.io.ObjectOutputStream
2. Convert the object stream into a KOML document.

Deserialization of a KOML object involves the reverse steps:

1. Convert the KOML document into an object stream.
2. Deserialize all objects with the class java.io.ObjectInputStream

Coins (JXML)

URL: http://www.jxml.com/coins/

API Documentation: http://www.jxml.com/coins/api/com/jxml/xml/package-summary.html

JXML home page: http://www.jxml.com/

Mailing List Archive: http://www.jxml.com/archive/java-xml-interest/

Coins is essentially a mechanism for connecting XML elements with JavaBeans. Bill la Forge, president of JXML, once said that a Coin consists of two "faces": an XML element is the persistent form, and the JavaBean instance in the runtime form. Coins has undergone many changes of focus since Bill la Forge first presented it as an alternative to Java serialization; the name "Coins" relates to its original EDI focus when la Forge worked for The Open Group. On the Coins mailing list, java-xml-interest, JP Morgenthal of NC.Focus succinctly summarized Coins in December 1998 as follows:

"Coins is a programming paradigm for associating elements with executable [behavior through] the use of a bindings document. Today these binding documents use JavaBeans (or they soon will), but they could use any supported execution environment. The purpose of Coins is to process XML documents that have nothing to do with development (ie. a Web page). Coins works by associating the Element name <HR> with the JavaBean to draw a horizontal rule on screen. Think of Coins as following the model/view/controller paradigm, whereby the model is the XML document, the view is bindings document (also written in XML), and the controller is the Coins runtime."

According to the Coins documentation:

"Coins uses a SAX-conformant parser and the Docuverse DOM SDK to convert an XML document into a [DOM] tree of objects, each object corresponding to an element in the XML document. The classes of the objects used to construct this tree fall into four groups, all of which must implement the W3C DOM Element interface:

1. The SimpleElement class, which supports ID attributes.
2. Application-specific classes. This includes the Bindings, Coin, and Link classes in the com.jxml.coins package.
3. The Wrapper class, for holding an application-specific object. If the application class has an appropriate constructor, the application object is given a reference to the wrapper object that holds it.
4. Wrapper classes generated with the Mint Utility. These wrappers use the bean property methods of the object they hold to connect that object with the data from the XML document."

XML and Java: DOM Level 1: Java XML API Definitions (W3C)
XML and Java: The Perfect Pair: Part 2: Java APIs for XML
XML and Java: Other APIs