Jackson正反序列化

• 范例1：List<T>
• 范例1：List<Map<String, T>>
• 范例2：Map<String, List<T>>

//先构造Map<String,Person>得到innerType,第一个参数为外层对象HashMap，第二个参数为String,第三个参数为Person
JavaType innerType = mapper.getTypeFactory().constructParametricType(HashMap.class, String.class, Person.class);
//再构造List<innerType> 
JavaType resultType = mapper.getTypeFactory().constructParametricType(ArrayList.class, innerType);
//反序列化
List<Map<String, Person>> result2 = mapper.readValue(s, resultType);