使用ObjectMapper读取嵌套的json文件

Question

我正在尝试在ObjectMapper的帮助下读取json文件（schools.json）。json的文件结构如下：

[
  {
    "schoolid": "X",
    "schoolname": "ABC",
    "schoolbranch": "DEF",
  },
 {
    "schoolid": "Y",
    "schoolname": "GDF",
    "schoolbranch": "HJG",
  },
]

而且这个json文件是从java读取的，如下所示：

static final String fileName = "schools.json";

     InputStream iStream = getClass().getClassLoader().getResourceAsStream(fileName);
          schools = objectMapper.readValue(iStream,
                  objectMapper.getTypeFactory().constructCollectionType(List.class, School.class));

现在我像这样更新json：

 [
      {
        "schoolid": "X",
        "schoolname": [{"original": "dfs"},{"translated":  "sfds"}],
        "schoolbranch":  [{"sub": "fdsf5"},{"major": "908fds"}],
      },
     {
        "schoolid": "Y",
        "schoolname": [{"original": "wera"},{"translated":  "sfds"}],
        "schoolbranch":  [{"sub": "mohk"},{"major": "908fds"}],
      },
 ]

因此School.java也已更改。在以前的版本中，每个字段都是一个String字段。现在schoolname和schoolbranch是其他具有原始字段，翻译字段等的模型/对象。

public class School {
private int schoolid;
private SchoolName schoolname;
private SchoolBranch schoolbranch;
... 
// getters and setters here
}

例如，SchoolName.java：

public class SchoolName {
private String original;
private String translated;
// etc.
}

现在，以上的Java代码块不起作用。 schools对象返回null。

我无法完成这项工作。我发现了一些示例，其中json字段包含数组，但是无法为我的案例应用类似的逻辑。感谢帮助。

Answer 1

正如Smutje和Smile所说，您的json对象是列表，而不是单个对象。将您的java School对象更改为：

public class School {
private int schoolid;
private List<SchoolName> schoolname;
private List<SchoolBranch> schoolbranch;
... 
// getters and setters here
}