Hson is a fastest JSON parser/generator for Android.

Hson

Hson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Hson can only run on the Android platform, is by far the fastest json parsing framework for the Android platform.

Goals

The fastest analysis speed
Provide simple toJson() and fromJson() methods to convert Java objects to JSON and vice-versa
Extensive support of Java Generics
Allow custom representations for objects
Support arbitrarily complex objects (with deep inheritance hierarchies and extensive use of generic types)

Performance comparison

HsonExample test

library	fromJson(time/millisecond)	toJson(time/millisecond)
Gson	20	28
fastjson	49	23
Hson	11	7

usage

Modify the build.gradle file in the root directory of the project as follows

buildscript {

    repositories {
        google()
        jcenter()
        // This repository must be added
        maven { url "https://dl.bintray.com/onepiece/maven" }
    }
    
    dependencies {
        // This gradle plugin must be added
        classpath 'com.hhh.onepiece:hson-plugin:1.0.1'
    }
  
    // Solve dependency problems
    allprojects {
        def rootRepositories = rootProject.buildscript.repositories
        rootRepositories.each { repo ->
            repositories.add(repo)
            buildscript.repositories.add(repo)
        }
    }

}

Modify the build.gradle file in the app directory as follows

apply plugin: 'com.android.application'
apply plugin: 'com.hhh.hson'

Modify the build.gradle file in the relevant library project (including app) directory as follows

dependencies {
    
    implementation 'com.hhh.onepiece:hson:1.0.1'
    annotationProcessor 'com.hhh.onepiece:hson-processor:1.0.0'
}

package com.hhh.hson;

import android.os.Bundle;
import android.util.Log;
import android.view.View;

import androidx.appcompat.app.AppCompatActivity;

import com.alibaba.fastjson.JSON;
import com.google.gson.Gson;
import com.hhh.hson.test.HsonExample;
import com.hhh.hson.test.NoValueHsonExample;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class MainActivity extends AppCompatActivity {

  private static final String TAG = "hhh";
  private static final String CHARSET_NAME = "utf-8";

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    test();
  }

  private void test() {
    findViewById(R.id.Hson_fromJson).setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        String json = getHsonExampleJson();
        long startTime = System.currentTimeMillis();
        NoValueHsonExample hsonExample = new NoValueHsonExample();
        Hson.fromJson(json, hsonExample);
        Log.e(TAG, "Hson_fromJson:" + (System.currentTimeMillis() - startTime));
      }
    });

    findViewById(R.id.Hson_toJson).setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        HsonExample hsonExample = new HsonExample();
        long startTime = System.currentTimeMillis();
        String json = Hson.toJson(hsonExample);
        Log.e(TAG, "Hson_toJson:" + (System.currentTimeMillis() - startTime));
      }
    });
  }

  private String getHsonExampleJson() {
    StringBuilder sb = new StringBuilder();
    try {
      InputStream is = getAssets().open("hsonExample.json");
      BufferedReader br = new BufferedReader(new InputStreamReader(is, CHARSET_NAME));
      String str;
      while ((str = br.readLine()) != null) {
        sb.append(str);
      }
      br.close();
      return sb.toString();
    } catch (IOException e) {
      e.printStackTrace();
    }
    return "";
  }
}