| API | SOURCE |
| --- | --- |
| Google GSON | [http://code.google.com/p/google-json/](http://code.google.com/p/google-json/) |
| SOJO | [http://sojo.sourceforge.net/](http://sojo.sourceforge.net/) |
| org.json (by Douglas Crockford) | [http://www.json.org/java](http://www.json.org/java) |
| json-lib | [http://sourceforge.net/projects/json-lib/](http://sourceforge.net/projects/json-lib/) |
| json-io | [http://code.google.com/p/json-io](http://code.google.com/p/json-io) |
| jsontools | [http://jsontools.berlios.de/](http://jsontools.berlios.de/) |
| jsonbeans | [http://code.google.com/p/jsonbeans/](http://code.google.com/p/jsonbeans/) |
| ActiveSupport JSON | [http://api.rubyonrails.org/classes/ActiveSupport/JSON.html](http://api.rubyonrails.org/classes/ActiveSupport/JSON.html) |
| Yajl | [https://github.com/brianmario/yajl-ruby](https://github.com/brianmario/yajl-ruby) |
| Oj | [https://github.com/ohler55/oj](https://github.com/ohler55/oj) |
Ruby on Rails提供了额外的功能，这使得转换Ruby对象为JSON更容易。下面的控制器使用ActionController的渲染方法输出地址对象到JSON:
~~~
class Person
attr_accessor :first_name, :last_name
def initialize(first_name=nil, last_name=nil)
@first_name = first_name
@last_name = last_name
end
end
class MyController < ApplicationController
def index
person = Person.new('John', 'Doe')
respond_to do |format|
format.html # index.html.erb
format.json { render :json => person}
end
end
end
~~~
Rails的应用控制器负责编写对象为JSON格式或者解析JSON文件为对象。所以没有必要在这里写to_json方法
