using JSON-SerDe in Hive tables

A bit hard to tell what's going on without the logs (see Getting Started) in case of doubt. Just a quick thought - can you try if it works with WITH SERDEPROPERTIESas so:

CREATE EXTERNAL TABLE my_table (field1 string, field2 int, 
                                field3 string, field4 double)
ROW FORMAT SERDE 'org.apache.hadoop.hive.contrib.serde2.JsonSerde'
WITH SERDEPROPERTIES (
  "field1"="$.field1",
  "field2"="$.field2",
  "field3"="$.field3",
  "field4"="$.field4" 
);

There is also a fork you might want to give a try from ThinkBigAnalytics.

UPDATE: Turns out the input in Test.json is invalid JSON hence the records get collapsed.

See answer https://stackoverflow.com/a/11707993/396567 for further details.