XStream is a simple library to serialize objects to XML and back again.
Features
- Ease of use. A high level facade is supplied that simplifies common use cases.
- No mappings required. Most objects can be serialized without need for specifying mappings.
- Performance. Speed and low memory footprint are a crucial part of the design, making it suitable for
large object graphs or systems with high message throughput.
- Clean XML. No information is duplicated that can be obtained via reflection. This results
in XML that is easier to read for humans and more compact than native Java serialization.
- Requires no modifications to objects. Serializes internal fields, including private and
final. Supports non-public and inner classes. Classes are not required to have default constructor.
- Full object graph support. Duplicate references encountered in the object-model will
be maintained. Supports circular references.
- Integrates with other XML APIs. By implementing an interface, XStream can serialize
directly to/from any tree structure (not just XML).
- Customizable conversion strategies. Strategies can be registered allowing customization of how
particular types are represented as XML.
- Error messages. When an exception occurs due to malformed XML, detailed diagnostics are provided
to help isolate and fix the problem.
- Alternative output format. The modular design allows other output formats. XStream ships currently
with JSON support and morphing.
Typical Uses
- Transport
- Persistence
- Configuration
- Unit Tests
Known Limitations
If using the enhanced mode, XStream can re-instantiate classes that do not have a default constructor.
However, if using a different JVM like an old JRockit version, a JDK 1.4 or you have restrictions because of a
SecurityManager, a default constructor is required.
The enhanced mode is also necessary to restore final fields for any JDK < 1.5. This implies deserialization of
instances of an inner class.
Auto-detection of annotations may cause race conditions. Preprocessing annotations is safe though.
Getting Started
Latest News
Nov 3, 2011 XStream 1.4.2 released
Maintenance release 1.4.2 of XStream with bug fixes and small improvements. Main changes:
- XStream libraries can be used now directly in Android, therefore support of Java 1.4.2 has been stopped with the delivery.
Anyone who needs a version for Java 1.4.2 can build it easily from source, this build is still supported and part of CI.
- New extended HierarchicalStreamReader interface with peekNextChild method. All XStream readers implement the new
interface (by Nikita Levyankov).
- Special support for Collections.EMPTY_LIST, Collections.EMPTY_SET and Collections.EMPTY_MAP and collections created
with Collections.singletonList(), Collections.singletonSet() and Collections.singletonMap().
- Support additional parameters for XStreamConverter annotation (e.g. to declare a ToAttributedValueConverter).
View the complete change log and download.
Thanks to this impressive list of contributors.