jackson 转换 enum 类型

REST API 接口要求 requster json 的 lifeCycle 域只能填 YOUNG, OLD，对于其他的 lifeCycle，都要给 requester 返回 bad request 消息。

public class DataCategory {    LifeCycle lifeCycle;

    public void setLifeCycle(LifeCycle lifeCycle) {        this.lifeCycle = lifeCycle;    }

    public LifeCycle getLifeCycle() {        return lifeCycle;    }

    public String getName() {        return name;    }

    public void setName(String name) {        this.name = name;    }

    String name;

    public static void main(String args[]) {        DataCategory dc = new DataCategory();

        dc.setName("name");        dc.setLifeCycle(LifeCycle.END_OF_SERVICE);

        ObjectMapper objectMapper = new ObjectMapper();        System.out.println(dc.toString());

        String jsonStr1 = "{\"lifeCycle\":\"END_OF_SERVICE\",\"name\":\"false\"}";

        try {            DataCategory newDC = objectMapper.readValue(jsonStr1, DataCategory.class);            System.out.println(newDC.getLifeCycle());

            System.out.println(String.valueOf(newDC.getLifeCycle()));        } catch (IOException e) {            e.printStackTrace();        }

        try {            System.out.println(objectMapper.writeValueAsString(dc));        } catch (Exception e) {            e.printStackTrace();        }    }}

jackson可以正常的进行序列化和反序列化。

但是插入到 mongodb 中时就报错，说序列化 class 失败。而getLifeCycle().toString()又不work。

因此使用 String.valueOf(getLifeCycle()) 来从 枚举类型转化到 String