ig-json-parser

General

Category
Free
Tag
JSON
License
N/A
Registered
Sep 12, 2014
Favorites
0
Link
https://github.com/Instagram/ig-json-parser
See also
jsonify
RapidJSON
gson-flatten
Jackson
Stag

Additional

Language
Java
Version
N/A
Created
Jun 11, 2014
Updated
Feb 5, 2018
Owner
Instagram
Contributors
ttung
Ravindra Kumar (ravidsrk)
TommyVisic
Jake Wharton (JakeWharton)
dreiss
kangzhang
jingibus
cjhopman
8
Activity
Badge
Generate
Download
Source code
APK file

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ig-json-parser

Fast JSON parser for java projects.

Getting started

The easiest way to get started is to look at maven-example. For more comprehensive examples, check out the unit tests or the demo.

Gradle

For Java projects, to use this library, add this to your build.gradle file:

allprojects {
  repositories {
    maven { url 'https://jitpack.io' }
  }
}

...

dependencies {
  compile 'com.github.instagram.ig-json-parser:runtime:master-SNAPSHOT' // the runtime
  compile 'com.github.instagram.ig-json-parser:processor:master-SNAPSHOT' // the annotation processor 
}

For Android projects using Android Studio 3.0+ or Gradle 4.0+, you can enable the annotation processor as following:

allprojects {
  repositories {
    maven { url 'https://jitpack.io' }
  }
}

...

dependencies {
  annotationProcessor 'com.github.instagram.ig-json-parser:processor:master-SNAPSHOT'
  implementation 'com.github.instagram.ig-json-parser:runtime:master-SNAPSHOT'
}

If you are using older gradle versions, you can use old apt plugin to integrate the annotation processor:

allprojects {
  repositories {
    maven { url 'https://jitpack.io' }
  }
}

...

apply plugin: 'com.neenbedankt.android-apt'

dependencies {
  apt 'com.github.instagram.ig-json-parser:processor:master-SNAPSHOT'
  compile 'com.github.instagram.ig-json-parser:runtime:master-SNAPSHOT'
}

If you are using other build sytems, please find instructions here

Requirements for model classes

There should be a package-visible no-argument constructor for each of your model classes. The fields also need to be package-visible.

Each class that needs a serializer/deserializer generated should be annotated with @JsonType. Each field that needs to be mapped to/from JSON should be annotated with @JsonField. The @JsonField annotation has one mandatory argument, which is the fieldname for the field in the JSON.

The following is an example of a very simple model class:

@JsonType
class Dessert {
  @JsonField(fieldName="type")
  String type;

  @JsonField(fieldName="rating")
  float rating;
}

Serializer/deserializer

Compiling your model classes with the annotations will automatically generate the serializer and deserializer. They will be in a generated class with the same name as your class, except with the suffix __JsonHelper. For example, to deserialize the Dessert class above, simply run the code:

Dessert parsed = Dessert__JsonHelper.parseFromJson(inputJsonString);

To serialize a class, run:

String serialized = Dessert__JsonHelper.serializeToJson(dessertObject);

Supported data types

The following scalar types are supported:

  • String
  • boolean/Boolean
  • int/Integer
  • long/Long
  • float/Float
  • double/Double

If a json field is another dictionary, it can be represented by another model class. That model class must also have the @JsonType annotation.

Lists of objects are supported either as Java Lists or Queues.

Proguard

Add the following lines to your proguard-rules file:

-dontwarn sun.misc.Unsafe
-dontwarn javax.annotation.**

Advanced features

Postprocessing

TODO: Document this. See the documentation in common/src/main/java/com/instagram/common/json/annotation/JsonType.java in the meanwhile.

Customized parsing code

TODO: Document this. See the documentation in common/src/main/java/com/instagram/common/json/annotation/JsonField.java in the meanwhile.

Optional serializer generation

To save generating serializer code if you only need deserialization, serializer generation can be disabled or enabled globally and per-class. The default is to generate serializers for all classes. To disable generation globally, pass

-AgenerateSerializer=false

to the command-line arguments of javac. To override the default generation option for a single class, see JsonType.generateSerializer().