场景描述：
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();
}
}
}
测试结果:
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
从测试结果来看：
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较大的fastjson和gson。而且在对速度没有极端追求的场景下也无需引入json-smart, 因为其可能仅仅只帮你节省了后台1s的时间，感官上其实察觉不明显。