Version 1.8 was released April 20th, 2011, about 4 months after JacksonRelease17; see JacksonDownload page.

As with all "minor versions", it is backwards compatible with earlier version, regarding public API; and with only minor changes with internal (or semi-public) interfaces. Set of such mostly-internal changes is included in release notes.

Goal for this version was to address "most wanted" features, both by users and development team. In addition, modular extensibility was a priority, so multiple improvements to JacksonFeatureModules were included.

• Customized low-level output encoding:
• http://jira.codehaus.org/browse/JACKSON-102: Allow forced escaping of non-ASCII characters, using JsonGenerator.Feature.ESCAPE_NON_ASCII (or JsonGenerator.setHighestNonEscapedChar
• http://jira.codehaus.org/browse/JACKSON-106: Added org.codehaus.jackson.io.CharacterEscapes which can be registered with JsonFactory, JsonGenerator, to add fully customized character escaping functionality.
• http://jira.codehaus.org/browse/JACKSON-178: Add support for JacksonFeaturePropertyNamingStrategy.
• http://jira.codehaus.org/browse/JACKSON-494: Add pluggable format auto-detection support
• Support added for basic JSON (JsonFactory), Smile (SmileFactory), as well as "jackson-xml-databinding" module (XmlFactory).
• Full support for configurable key serializers, deserializers:
• http://jira.codehaus.org/browse/JACKSON-513: Add methods for registering key serializers, deserializers, via Module API
• http://jira.codehaus.org/browse/JACKSON-519: Add support for contextual serializers, deserializers.

• http://jira.codehaus.org/browse/JACKSON-43: Add ObjectMapper.readValues(), ObjectReader.readValues() to allow convenient binding of sequences (arrays, root-level sequences) of values.
• http://jira.codehaus.org/browse/JACKSON-204 Add feature to allow deserializing empty Strings as nulls (for POJOs).
• http://jira.codehaus.org/browse/JACKSON-427 JsonNode: add "upsert" accessor for JsonNode (although only usable for ObjectNode); JsonNode.with(String property) -- gets or creates ObjectNode-valued property of an ObjectNode.
• http://jira.codehaus.org/browse/JACKSON-464: Add SimpleAbstractTypeResolver to allow defining mapping from abstract types to concrete types (like, say, from java.util.Collection to java.util.HashSet)
• http://jira.codehaus.org/browse/JACKSON-520: Add "FormatSchema" abstraction (mostly a tag interface); add to JsonGenerator, JsonParser, as well as to ObjectMapper, ObjectReader and ObjectWriter. For latter group of objects it will just passed to generators and parsers as opaque value.
• http://jira.codehaus.org/browse/JACKSON-521 Add a mechanism to indicate that certain non-Collection/Map types be considered Collections, Maps, by framework (needed by Scala plug-in)
• http://jira.codehaus.org/browse/JACKSON-526: Add JacksonFeaturesDeserialization.ACCEPT_SINGLE_VALUE_AS_ARRAY, which allows implicit conversions in case where JSON format is omitting JSON array surroinding a single value (sort of invalid structure produced by some XML-to-JSON converters)
• http://jira.codehaus.org/browse/JACKSON-527: Add HandlerInstantiator abstraction (to implement, register with ObjectMapper) to allow customizing details of how JsonDeserializer, JsonSerializer, TypeIdResolver instances (and any other handler types added in future) are constructed: useful for integrating with Dependency Injection frameworks, work around class loader issues.

• http://jira.codehaus.org/browse/JACKSON-142: Add JacksonFeaturesParser.ALLOW_NON_NUMERIC_NUMBERS (JacksonFeaturesNonStandard) feature that allows parsing "NaN", "+INF"/"+Infinite", "-INF"/"-Infinite" as double values
• http://jira.codehaus.org/browse/JACKSON-358: JsonParser: optional support for accepting leading zeroes for numbers
• http://jira.codehaus.org/browse/JACKSON-459: Add mapper-level configuration to allow default ordering of serialized properties
• http://jira.codehaus.org/browse/JACKSON-487: Change DeserializationConfig.Feature.USE_ANNOTATIONS to fully block introspection of any annotations
• http://jira.codehaus.org/browse/JACKSON-502: Change JacksonFeatureMaterializedBeans functionality be basic JacksonFeatureModules (to simplify registration)
• http://jira.codehaus.org/browse/JACKSON-512: Allow decorating InputStream/OutputStream (and other sources/destinations) when creating JsonParser, JsonGenerator
• http://jira.codehaus.org/browse/JACKSON-555: Add JsonParser.getInputSource(), JsonGenerator.getOutputTarget() to give access to raw stream/reader/writer objects.

• http://jira.codehaus.org/browse/JACKSON-132 (note: '''high vote count'''): Allow inlining/unwrapping of child objects
• http://jira.codehaus.org/browse/JACKSON-275: Support multi-argument setters (to allow co-constraints)
• http://jira.codehaus.org/browse/JACKSON-279: Retain timezone information during serialization, deserialization
• http://jira.codehaus.org/browse/JACKSON-350: Resolve classloading issues (for eg. OSGi) without changing API
• http://jira.codehaus.org/browse/JACKSON-406: Allow injection of values during deserialization
• Also: http://jira.codehaus.org/browse/JACKSON-471: similarly, allow injection during serialization
• http://jira.codehaus.org/browse/JACKSON-453: Support for 'external type id'; and possibly related issues:
• http://jira.codehaus.org/browse/JACKSON-437: Support to set logical property with value of type id that was used for deserialization
• http://jira.codehaus.org/browse/JACKSON-490 Allow subclasses to "inherit" @JsonCreator annotation from superclass constructor

CategoryJackson