Jackson - 带有多个条目的 Json 到 POJO [英] Jackson - Json to POJO With Multiple Entries

问题描述

我知道文件 User.json 是否有

I know If the file User.json has

{
  "name" : { "first" : "Joe", "last" : "Sixpack" },
  "gender" : "MALE",
  "verified" : false,
  "userImage" : "Rm9vYmFyIQ=="
}

我可以像这样构造一个 User 对象:

I can construct a single User object like this :

User user = mapper.readValue(new File("user.json"), User.class);

但是如果文件 User.json 有，我如何构造一个对象列表:

But how do I construct a list of objects if the file User.json has :

{
  "name" : { "first" : "Joe", "last" : "Sixpack" },
  "gender" : "MALE",
  "verified" : false,
  "userImage" : "Rm9vYmFyIQ=="
},
{
  "name" : { "first" : "Jane", "last" : "Austen" },
  "gender" : "FEMALE",
  "verified" : false,
  "userImage" : "DFREWEWE=="
}

?

推荐答案

多种方式:如果你有这些的 JSON 数组，你可以这样做:

Multiple ways: if you have a JSON array of these, you can do:

User[] users = mapper.readValue(json, User[].class);

或者，如果它只是一系列根级别值，您可以这样做:

or, if it is just a sequence of root level values you can do:

Iterator<User> it = mapper.readValues(json, User.class);

并迭代值(添加到列表等)

and iterate over values (add to a List or such)

这篇关于Jackson - 带有多个条目的 Json 到 POJO的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！