Limitations of the JSON4J libraries

The JSON (JavaScriptTM Object Notation) string parsing follows the guidelines presented by multiple reference sources on the format of JSON text.  Primarily, according to all sources reviewed, attribute names are always quoted strings. 

See the following JSON structure:
{
   "attributeName": "foo"
}

However, for browsers that support attribute names without quotation marks; attribute names still evaluate correctly.  This library follows the definition of the JSON format and is more rigid than most browsers.  The library will not evaluate unquoted attribute names as valid JSON. Instead, JSON4J will generate a java.io.IOException exception.  Therefore, always use correctly quoted attribute names in JSON text that you pass into the parse functions of this library.