JsonArray与Gson对null处理

/**
 * Json 示例
 */
public class JsonDemo {
    private static Map<String,Object> map = new HashMap<>();
    static {
        map.put("id","");
        map.put("name",null);
        map.put("six",0);
        map.put("address","xxx");
    }
    @Test
    public void gsonTest(){
        Gson gson = new Gson();
        System.out.println(gson.toJson(map));
    }
    @Test
    public void gsonBuilderTest(){
        Gson gson = new GsonBuilder().serializeNulls().create();
        System.out.println(gson.toJson(map));
    }
    @Test
    public void jsonArrayTest(){
        String s = JSONArray.toJSONString(map);
        System.out.println(s);
    }
    @Test
    public void jsonArrayTest2(){
        String s = JSONArray.toJSONString(map, SerializerFeature.WriteMapNullValue);
        System.out.println(s);
    }
}