Android解析Json速度最快的库:json-smart

场景描写叙述：

本文仅验证了在安卓环境下使用Json的Key作为反序列化条件的解析速度。结论是解析速度最快的不是阿里的fastjson，也不是Google的Gson，而是json-smart。

Android 4.4.2

fastjson-1.1.34.android.jar

gson-2.2.4.jar

json-smart-2.0-RC3.jar

**注意场景的限定条件**

核心代码：

package com.h3c.mytestview;

import java.io.StringReader;

import net.minidev.json.JSONValue;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.google.gson.Gson;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.stream.JsonReader;

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        new Thread(new Runnable() {
            @Override
            public void run() {
                doSth();
            }
        }).start();
    }

    private void doSth() {
        Log.e("H6c","start...");
        String json = "{\"name\":\"reiz\"}";
        String k = "";
        try {
            long startTime1 = System.currentTimeMillis();
            for(int n = 0;n < 100000; n++) {
                org.json.JSONObject jo;
                    jo = new org.json.JSONObject(json);
                k = jo.getString("name");
            }
            long endTime1 = System.currentTimeMillis() - startTime1;
            Log.e("H6c","android:"+ endTime1);

            long startTime2 = System.currentTimeMillis();
            for(int n = 0;n < 100000; n++) {
                JSONObject jo = JSON.parseObject(json);
                k = jo.getString("name");
            }
            long endTime2 = System.currentTimeMillis() - startTime2;
            Log.e("H6c","fastjson:"+ endTime2);

            long startTime3 = System.currentTimeMillis();
            for(int n = 0;n < 100000; n++) {
                net.minidev.json.JSONObject jo = (net.minidev.json.JSONObject)JSONValue.parseStrict(json);
                k = (String)jo.get("name");
            }
            long endTime3 = System.currentTimeMillis() - startTime3;
            Log.e("H6c","json-smart:"+endTime3);

            long startTime4 = System.currentTimeMillis();
            for(int n = 0;n < 100000; n++) {
                JsonElement je = new JsonParser().parse(json);
                JsonObject jo = je.getAsJsonObject();
                k = jo.get("name").getAsString();
            }
            long endTime4 = System.currentTimeMillis() - startTime4;
            Log.e("H6c","gson:"+endTime4);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

測试结果:

Galaxy S3

===========Galaxy S3=============1
05-22 11:04:17.120: E/H6c(28681): start...
05-22 11:04:21.525: E/H6c(28681): android:4400
05-22 11:04:28.135: E/H6c(28681): fastjson:6608
05-22 11:04:31.600: E/H6c(28681): json-smart:3467
05-22 11:04:47.440: E/H6c(28681): gson:15839
===========Galaxy S3=============2
05-22 11:05:08.230: E/H6c(28681): start...
05-22 11:05:12.120: E/H6c(28681): android:3886
05-22 11:05:17.285: E/H6c(28681): fastjson:5167
05-22 11:05:21.020: E/H6c(28681): json-smart:3736
05-22 11:05:34.040: E/H6c(28681): gson:13018
===========Galaxy S3=============3
05-22 11:05:45.440: E/H6c(28681): start...
05-22 11:05:49.470: E/H6c(28681): android:4033
05-22 11:05:54.500: E/H6c(28681): fastjson:5031
05-22 11:05:58.240: E/H6c(28681): json-smart:3736
05-22 11:06:13.485: E/H6c(28681): gson:15245

Galaxy S4

===========Galaxy S4=============1
05-22 10:58:03.541: E/H6c(26600): start...
05-22 10:58:06.934: E/H6c(26600): android:3393
05-22 10:58:12.680: E/H6c(26600): fastjson:5752
05-22 10:58:15.232: E/H6c(26600): json-smart:2549
05-22 10:58:24.841: E/H6c(26600): gson:9610

===========Galaxy S4=============2
05-22 11:00:51.675: E/H6c(26600): start...
05-22 11:00:54.878: E/H6c(26600): android:3209
05-22 11:01:00.413: E/H6c(26600): fastjson:5526
05-22 11:01:02.986: E/H6c(26600): json-smart:2569
05-22 11:01:11.084: E/H6c(26600): gson:8099

===========Galaxy S4=============3
05-22 11:01:31.213: E/H6c(26600): start...
05-22 11:01:34.717: E/H6c(26600): android:3508
05-22 11:01:40.172: E/H6c(26600): fastjson:5443
05-22 11:01:42.734: E/H6c(26600): json-smart:2566
05-22 11:01:52.554: E/H6c(26600): gson:9823

Xiaomi3

===========Xiaomi 3=============1
05-22 11:02:05.461: E/H6c(30473): start...
05-22 11:02:08.021: E/H6c(30473): android:2561
05-22 11:02:11.781: E/H6c(30473): fastjson:3766
05-22 11:02:13.411: E/H6c(30473): json-smart:1629
05-22 11:02:16.811: E/H6c(30473): gson:3402

===========Xiaomi 3=============2
05-22 11:02:30.291: E/H6c(30473): start...
05-22 11:02:32.481: E/H6c(30473): android:2184
05-22 11:02:36.341: E/H6c(30473): fastjson:3856
05-22 11:02:37.781: E/H6c(30473): json-smart:1439
05-22 11:02:40.991: E/H6c(30473): gson:3210

===========Xiaomi 3=============3
05-22 11:02:47.731: E/H6c(30473): start...
05-22 11:02:50.271: E/H6c(30473): android:2548
05-22 11:02:53.831: E/H6c(30473): fastjson:3553
05-22 11:02:55.261: E/H6c(30473): json-smart:1431
05-22 11:02:58.571: E/H6c(30473): gson:3310

从測试结果来看：

在使用key解析json的场景下，速度最快的是json-smart，其解析速度有所提升。

本文研究的结论是Android原生Java解析已经具备基础json解析能力，并且在速度上有一定的优势，在简单的场景下无需引用噱头比較大的fastjson和gson。并且在对速度没有极端追求的场景下也无需引入json-smart, 由于其可能只只帮你节省了后台1s的时间，感官上事实上察觉不明显。