public static <T> T toObject(String str, TypeReference<T> valueTypeRef)throws Exception{
    if(str==null){
        return null;
    }
    return mapper.readValue(str, valueTypeRef);
}

List<User> users = DataUtil.getUsers();
String str = JacksonUtil.toString(users, false);
List<User> users2 = JacksonUtil.toObject(str, new TypeReference<List<User>>() {});
for(User user:users2) {
    System.out.println(user.getClass()+"#"+user);
}
		
new TypeReference<List<User>>() {}
		



完整代码
https://gitee.com/dyyx/demos/blob/master/jackson/src/test/java/dyyx/JacksonUtilTest.java