Overview

This project contains core low-level incremental ("streaming") parser and generator abstractions used by Jackson Data Processor. It also includes the default implementation of handler types (parser, generator) that handle JSON format. The core abstractions are not JSON specific, although naming does contain 'JSON' in many places, due to historical reasons. Only packages that specifically contain word 'json' are JSON-specific.

This package is the base on which Jackson data-binding package builds on. It is licensed under Apache License 2.0. For additional/alternative licensing questions, please contact info@fasterxml.com: affordable commercial licenses available for use cases like Android app development.

Alternate data format implementations (like Smile (binary JSON), XML, CSV) and CBOR also build on this base package, implementing the core interfaces, making it possible to use standard data-binding package regardless of underlying data format.

Project contains versions 2.0 and above: source code for earlier (1.x) versions can be found from Jackson-1 github repo.

Get it!

Maven

Functionality of this package is contained in Java package com.fasterxml.jackson.core.

To use the package, you need to use following Maven dependency:

<dependency>
  <groupId>com.fasterxml.jackson.core</groupId>
  <artifactId>jackson-core</artifactId>
  <version>${jackson.version.core}</version>
</dependency>

or download jars from Maven repository or links on Wiki. Core jar is a functional OSGi bundle, with proper import/export declarations.

Package has no external dependencies, except for testing (which uses JUnit).

Non-Maven

For non-Maven use cases, you download jars from Central Maven repository.

Core jar is also a functional OSGi bundle, with proper import/export declarations, so it can be use on OSGi container as is.

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Use it!

General

Usage typically starts with creation of a reusable (and thread-safe, once configured) JsonFactory instance:

JsonFactory factory = new JsonFactory();
// configure, if necessary:
factory.enable(JsonParser.Feature.ALLOW_COMMENTS);

Alternatively, you have a ObjectMapper (from Jackson Databind package) handy; if so, you can do:

JsonFactory factory = objectMapper.getFactory();

More information can be found from Streaming API.

Usage, simple reading

All reading is by using JsonParser (or its sub-classes, in case of data formats other than JSON), instance of which is constructed by JsonFactory.

An example can be found from Reading and Writing Event Streams

Usage, simple writing

All writing is by using JsonGenerator (or its sub-classes, in case of data formats other than JSON), instance of which is constructed by JsonFactory:

An example can be found from Reading and Writing Event Streams

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Further reading

Differences from Jackson 1.x

Project contains versions 2.0 and above: source code for earlier (1.x) versions is available from Codehaus SVN repository

Note that the main differences compared to 1.0 core jar are:

• Maven build instead of Ant
• Annotations carved out to a separate package (that this package depends on)
• Java package is now com.fasterxml.jackson.core (instead of org.codehaus.jackson)

Links

• Project Wiki has JavaDocs and links to downloadable artifacts
• Jackson Github Hub has links to all official Jackson components
• Jackson Github Doc is the hub for official Jackson documentation
• FasterXML Jackson Project Wiki has additional documentation (especially for older Jackson versions)