gson-flatten

Library to collapse inner objects when parsing json

1. To use library you should add it in your build.gradle:

    compile 'org.itishka.gson-flatten:gson-flatten:0.7'

2. Then register it in your gson builder:

   final Gson gson = new GsonBuilder()
   
     .registerTypeAdapterFactory(new FlattenTypeAdapterFactory())
   
     .create();
   

3. Define your class and use @Flatten annotation to get data from embedded objects. For example class

   class Weather {
   
   @Flatten("temperature::min")
   int min_temperture;
   @Flatten("temperature::max")
   int max_temperture; 
   }
   

   will be filled with data from json

   {
   
   "temperature": {
   
   "min": -273,
   
   "max": 1000
   
   }
    
   }
   

4. Then just parse or serialize json as your usually do:

     String json = gson.toJson(weather);
   
   Weather weather2 = gson.fromJson(json, Weather.class);
   

Additional features

• You can skip field name if it equlas in inner object and outer one. E.g.:

class Weather {

  @Flatten("temperature::")
  int min;
  @Flatten("temperature::")
  int max; 
}

• You can get array items as well (tnx @tominsam):

class SomeClass {

  @Flatten("some_array::0")
  int first_value; 
}

• If you are using Gson 2.7 with some FieldNamingStrategies with and gson-flatten 0.6 you do not need to do anything more!

With previous versions of gson and gson-flatten you should provide FieldNamingStrategy to FlattenTypeAdapterFactory:

final Gson gson = new GsonBuilder()

  .setFieldNamingPolicy(FieldNamingPolicy.UPPER_CAMEL_CASE)

  .registerTypeAdapterFactory(new FlattenTypeAdapterFactory(FieldNamingPolicy.UPPER_CAMEL_CASE))

  .create();

License

Based on https://github.com/noties/Flatten

Gson-flatten is released under LGPL 3.0 license