Question

My service(written in Java) returns me an output in the format:

 "serviceMetricList": 
  [
    {"MetricDataList": 
      {"metricDataList": 
        [
          {"metricDate": "2011-04-05T14:50:00.000Z", 
           "metricValue": "427448.0"}, 
          {"metricDate": "2011-04-12T14:30:00.000Z", 
           "metricValue": "430089.0"}
        ]
      }, 
     "urlSerialNo": "1"}
     }
  ]

I need to retrieve the values metricDate and metricValue from my Ruby client. Am not sure about how this can be done. Any help in this regard will be great.

Answer 1

If you want to parse this data format, you first need to know what data format it is. It doesn’t appear to be any well-known data format and it’s not any format I know. It’s obviously not JSON, nor is it YAML and definitely not XML.

So, you’ll probably have to write your own parser. Or a preprocessor which converts the data into a more well-known format, for wich a parser already exists.

For example, if you were to convert the example to YAML, it would look something like this:

"serviceMetricList": 
  [
    {"MetricDataList": 
      {"metricDataList": 
        [
          {"metricDate": "2011-04-05T14:50:00.000Z", 
           "metricValue": "427448.0"}, 
          {"metricDate": "2011-04-12T14:30:00.000Z", 
           "metricValue": "430089.0"}
        ]
      }, 
     "urlSerialNo": "1"
    }
  ]

And you could parse it like this:

require 'yaml'
h = YAML.load(your_java_data)

Date.parse(h['serviceMetricList'][0]['MetricDataList']['metricDataList'][0]['metricDate'])
# => #<Date: 2011-04-05 (4911313/2,0,2299161)>

Float(h['serviceMetricList'][0]['MetricDataList']['metricDataList'][0]['metricValue'])
# => 427448.0

# or maybe, if you don't like to lose precision:
require 'bigdecimal'

BigDecimal(h['serviceMetricList'][0]['MetricDataList']['metricDataList'][0]['metricValue'])
# => #<BigDecimal:eb8240,'0.427448E6',8(12)>