fastJson將對象序列化成json字符串

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.60</version>
        </dependency>

JSON_OBJ_STR = "{"studentName":"lily","studentAge":12}";
JSON_ARRAY_STR = "[{"studentName":"lily","studentAge":12},{"studentName":"lucy","studentAge":15}]";

COMPLEX_JSON_STR="{"teacherName":"crystall","teacherAge":27,"course":{"courseName":"english","code":1270},"students":[{"studentName":"lily","studentAge":12},{"studentName":"lucy","studentAge":15}]}";

字符串轉json對象：JSONObject jsonObject = JSON.parseObject(JSON_OBJ_STR);

字符串轉json數組：JSONArray jsonArray = JSON.parseArray(JSON_ARRAY_STR);

字符串轉復雜json對象（嵌套）：JSONObject jsonObject = JSON.parseObject(COMPLEX_JSON_STR);

獲取嵌套里面的對象：JSONObject innerObject = jsonObject.getJSONObject("xxx");

json字符串轉javaBean：Student student = JSON.parseObject(JSON_OBJ_STR, new TypeReference<Student>() {});

復雜對象同上一樣轉；

javaBean 轉json字符串：String bookjson = JSONObject.toJSONString(book, SerializerFeature.WriteNullStringAsEmpty, SerializerFeature.WriteNullBooleanAsFalse)；

上面的SerializerFeature有好多枚舉類型，上面的是null值寫成“”，還有空值不寫進字符串的

SerializerFeature.NotWriteDefaultValue,比如studentName為空的時候，序列化成json字符串就是{"studentAge":"21"},沒有sthdentName