FastJson和Gson和Json数据解析分析和用法

首先分析下目前号称最快的FastJson，这个是全部人都验证过的，解析速度确实比较快，不过也须要根据数据量来看，数据量小的时候，Gson性能要稍微优于FastJson，但在数据量大解析的状况下，FastJson的速度就要明显快于Gson。具体缘由，我没研究过，只是作过测试，确实是这样。

性能测试代码以下：

/** * 测试Bean类 */
public class TestBean { private String name; private int age; private String no; public TestBean() { } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int j) { this.age = j; } public String getNo() { return no; } public void setNo(String no) { this.no = no; } }

/** * 比较FastJson和Gson的效率 */
    public void comparedFastJsonAndGson() { List<TestBean> list = new ArrayList<>(); int j = 0; TestBean u = null; //数据生成 while (j < 1000000) { u = new TestBean(); u.setAge(j); u.setName("zhangsan " + j); u.setNo("" + j); list.add(u); j++; } //作测试时，两个方法不要同时使用，注释掉另外一个分别运行，而后再比较时间，否则结果不许 // FastJson性能测试 fastJsonTest(list); System.out.println("!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"); // Gson性能测试 gsonTest(list); } /** * FastJsonTest * * @param list */ private void fastJsonTest(List<TestBean> list) { long s = System.currentTimeMillis(); System.out.println("before alibaba:" + s); String aliJson = com.alibaba.fastjson.JSON.toJSONString(list); long e = System.currentTimeMillis(); System.out.println("after alibaba:" + e); System.out.println("beanToJson:" + (e - s)); list = null; long s3 = System.currentTimeMillis(); List<TestBean> sult = JSON.parseArray(aliJson, TestBean.class); // List<U> sult = (List<U>) JSONObject.parse(aliJson); long e3 = System.currentTimeMillis(); System.out.println("JsonTobean:" + (e3 - s3)); } /** * GsonTest * * @param list */ private void gsonTest(List<TestBean> list) { long s1 = System.currentTimeMillis(); System.out.println("before Gson:" + s1); Gson gson = new Gson(); String gsonStr = gson.toJson(list); long e1 = System.currentTimeMillis(); System.out.println("after Gson:" + e1); System.out.println("beanToJson:" + (e1 - s1)); list = null; long s4 = System.currentTimeMillis(); // type 获取List<U>类型的class Type type = new TypeToken<List<TestBean>>() { }.getType(); List<TestBean> sult2 = gson.fromJson(gsonStr, type); long e4 = System.currentTimeMillis(); System.out.println("JsonTobean:" + (e4 - s4)); }

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下面介绍下两种解析方式的具体使用方法（这里使用的是K780数据网的5~7每天气预报信息）

/** * @author Jerry 2016.4.15 * */ public class Weather { private String days; // 日期 private String week; // 星期 private String citynm; // 城市/地区 private String temperature;// 温度 private String weather; // 天气 private String wind;// 风向 private String winp;// 风力 public Weather() { } public String getDays() { return days; } public void setDays(String days) { this.days = days; } public String getWeek() { return week; } public void setWeek(String week) { this.week = week; } public String getCitynm() { return citynm; } public void setCitynm(String citynm) { this.citynm = citynm; } public String getTemperature() { return temperature; } public void setTemperature(String temperature) { this.temperature = temperature; } public String getWeather() { return weather; } public void setWeather(String weather) { this.weather = weather; } public String getWind() { return wind; } public void setWind(String wind) { this.wind = wind; } public String getWinp() { return winp; } public void setWinp(String winp) { this.winp = winp; } @Override public String toString() { return "Weather [days=" + days + ", week=" + week + ", citynm=" + citynm + ", temperature=" + temperature + ", weather=" + weather + ", wind=" + wind + ", winp=" + winp + "]"; } }

/** * @author Jerry */ public class WeatherGson { private String success; private List<Weather> result; // 此处List 名字，必须为Json数组中键的名字，必须相同 public WeatherGson() { } public WeatherGson(String success, List<Weather> result) { this.success = success; this.result = result; } public String getSuccess() { return success; } public void setSuccess(String success) { this.success = success; } public List<Weather> getList() { return result; } public void setList(List<Weather> list) { this.result = list; } @Override public String toString() { return "WeatherJson [success=" + success + ", list=" + result + "]"; } }

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如下因此方法都卸载JsonDemo类中

/** * 获取网络Json数据String * * @param weaid * @return */ public String getJsonData() { System.out.println("请等待..."); String url = "http://api.k780.com:88/?app=weather.future&weaid=1&&appkey=10003&sign=b59bc3ef6191eb9f747dd4e83c99f2a4&format=json"; //将获取到的数据转换成字符串，此处是我本身封装的工具类 String jsonData = HttpUitls.doPostToString(url, "utf-8"); return jsonData; }

首先是FastJson的解析：

/** * fastJson 解析 * * @param jsonData * @return */ public List<Weather> fastJsonParser(String jsonData) { // 获取jsonObject对象 JSONObject object = JSON.parseObject(jsonData); String success = object.getString("success"); if ("1".equals(success)) { // 从jsonObject对象中获取 result 对象的值（Json数组） String result = object.getString("result"); // 将Json数组转换成List集合 List<Weather> list = JSON.parseArray(result, Weather.class); return list; } else { throw new RuntimeException("获取信息失败:" + success); } }

接着是Gson的解析：

/** * Gson 解析 * * @param jsonData */ public List<Weather> gsonParser(String jsonData) { Gson gson = new Gson(); System.out.println(jsonData); // List<Weather> list2 = gson.fromJson(jsonData, new // TypeToken<List<Weather>>(){}.getType()); WeatherGson fromJson = gson.fromJson(jsonData, WeatherGson.class); if ("1".equals(fromJson.getSuccess())) { return fromJson.getList(); } else { throw new RuntimeException("获取信息失败:" + fromJson.getSuccess()); } }

最后是Json解析：

/** * Json解析 * * @param jsonData * @return */ public List<Weather> jsonParser(String jsonData) { list = new ArrayList<>(); try { org.json.JSONObject object = new org.json.JSONObject(jsonData); JSONArray result = object.getJSONArray("result"); for (int i = 0; i < result.length(); i++) { org.json.JSONObject object2 = result.getJSONObject(i); this.weather = new Weather(); String days = object2.getString("days"); String week = object2.getString("week"); String citynm = object2.getString("citynm"); String temperature = object2.getString("temperature"); String weather = object2.getString("weather"); String wind = object2.getString("wind"); String winp = object2.getString("winp"); this.weather.setDays(days); this.weather.setWeek(week); this.weather.setCitynm(citynm); this.weather.setTemperature(temperature); this.weather.setWeather(weather); this.weather.setWind(wind); this.weather.setWinp(winp); list.add(this.weather); } return list; } catch (JSONException e) { e.printStackTrace(); } return null; }

Main：

public class Main { public static void main(String[] args) { JsonDemo jsonDemo = new JsonDemo(); // 比较FastJson和Gson 的效率 jsonDemo.comparedFastJsonAndGson(); // 从网络获取Json数据 String jsonData = jsonDemo.getJsonData(); // 使用Json获取数据集合 List<Weather> list = jsonDemo.jsonParser(jsonData); for (Weather weather : list) { System.out.println(weather); } // 使用FastJson 获取数据集合 List<Weather> list2 = jsonDemo.fastJsonParser(jsonData); for (Weather weather : list2) { System.out.println(weather); } // 使用Gson 获取数据集合 List<Weather> list3 = jsonDemo.gsonParser(jsonData); for (Weather weather : list3) { System.out.println(weather); } } }from: http://www.voidcn.com/blog/ming2316780/article/p-5811077.html