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