Gson：比较两个JSON字符串是否完全相等
一，no POJO，即不另外创建一个简单Java类
[java]
String str1 = "{\"properties\":{\"packet\":{\"recorded_at\":\"2015-09-02 04:45:45
+0000\",\"userId\":\"100000000000001\",\"meta\":
{\"account\":\"xxx\",\"event\":\"track\"},\"fields\":
{\"gyroData\":{\"rotation_y\":-1,\"rotation_z\":-1,\"rotation_x\":-1},\"accelerometerData\":
{\"acceleration_x\":-1,\"acceleration_z\":-1,\"acceleration_y\":-1},\"location\":
{\"speed\":4.68,\"speed_course\":0.7,\"horizontal_accuracy\":10,\"longtitude\":-122.02359082,
\"vertical_accuracy\":-1,\"latitude\":37.33385024},\"pedometerData\":{\"step_count\":0}},
\"recorded_sample_rate\":5}},\"geometry\":{\"type\":\"Point\",\"coordinates\":[37.33385024,-122.02359082]},
\"type\":\"Feature\"}";
String str2 = "{\"properties\":
{\"packet\":
{\"recorded_at\":\"2015-09-02 04:45:45 +0000\",\"userId\":\"100000000000001\",
\"meta\":{\"account\":\"xxx\",\"event\":\"track\"},\"fields\":{\"gyroData\":{\"rotation_y\":-1,
\"rotation_z\":-1,\"rotation_x\":-1},\"accelerometerData\":{\"acceleration_x\":-1,
\"acceleration_z\":-1,\"acceleration_y\":-1},\"location\":{\"speed\":4.68,\"speed_course\":0.7,
\"horizontal_accuracy\":10,\"longtitude\":-122.02359082,\"vertical_accuracy\":-1,\"latitude\":37.33385024},
\"pedometerData\":{\"step_count\":0}},\"recorded_sample_rate\":5}},\"geometry\":{\"type\":\"Point\",
\"coordinates\":[37.33385024,-122.02359082]},\"type\":\"Feature\"}";// method 1
[java] import com.google.gson.JsonObject; import com.google.gson.JsonParser; JsonParser parser = new JsonParser(); JsonObject obj = (JsonObject) parser.parse(str1); JsonParser parser1 = new JsonParser(); JsonObject obj1 = (JsonObject) parser1.parse(str2); System.out.println(obj.equals(obj1));
//method 2
[java] import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.JsonElement; Gson gson1 = new GsonBuilder().create();//or new Gson() JsonElement e1 = gson1.toJsonTree(str1);//or new Gson() Gson gson2 = new GsonBuilder().create(); JsonElement e2 = gson2.toJsonTree(str2); System.out.println(e1.equals(e2));
//method 3
[java] import com.google.gson.JsonElement; import com.google.gson.JsonPrimitive; JsonElement e3 = new JsonPrimitive(str1); JsonElement e4 = new JsonPrimitive(str2); System.out.println(e3.equals(e4));
reference：
Gson: Directly convert String to JsonObject (no POJO)
二，使用简单POJO类，和mentor Yang讨论过这个问题，哪怕这个JSON字符串有多么复杂，一般情况下五层就达到上限了（上面那个Json String看起来那么”复杂“，才三层）。
这里只是举个简单的栗子。因为这种方法看起来比第一种方式麻烦多了。
步骤就是先建一个（或者多个）POJO类，类中的属性名和JSON字符串中的key名一一对应。
然后：
[java]
<span style="white-space:pre"> </span>Gson gson = new Gson();//new一个Gson对象
//json字符串
String json = "{\"name\":\"guolicheng\",\"id\":123456,\"date\":\"2013-4-13 12:36:54\"}";
//new 一个Product对象
Product product = new Product();
//将一个json字符串转换为java对象
<strong><span style="color:#ff0000;">product = gson.fromJson(json, Product.class);</span></strong>
//输出
System.out.println("Name:" + product.getName());
System.out.println("Id:" + product.getId());
System.out.println("Date:" + product.getDate());reference：