将映射到dyanmodb的映射序列化为json

Question

要在下面的类中将Map的属性归类，我想使用DynamoDBMapper从Dyanmodb中进行保存和读取。

    Map<String, Map<String, Transition>> twf;

public class Transition {

    public String fst;
    public Permission pm;
    public List<Action> ac;
}

public class Action {
    private String mdl;
    private String dsc;
    private String nm;
    // email address or any other data
    private Map<String, String> data;
}

我尝试将DynamoDBTypeConverted转换为String，这导致json字符串已“转义为\”，并且在dyanmodb中不可读。我想存储为json

我实现了Dyanmodb支持Map的理解，但是仍然出现错误： 异常处理消息：不支持；需要@DynamoDBTyped或@DynamoDBTypeConverted

    public class TimeSheetWorkFlowConverter implements
            DynamoDBTypeConverter<Map<String, Object>, Map<String, Map<String, Transition>>> {

    @Override
        public Map convert(Map<String, Map<String, Transition>> object) {
            // Map obj = mapper.readValue(object, Map.class);
            String newJson = null;
            Map objectJson = null;
            try {
                newJson = mapper.writeValueAsString(object);
                objectJson = mapper.readValue(newJson, Map.class);
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return objectJson;
        }

        @SuppressWarnings("unchecked")
        @Override
        public Map<String, Map<String, Transition>> unconvert(Map<String, Object> object) {
            Map<String, Map<String, Transition>> wf = new HashMap<>();

            if (object != null && !object.isEmpty())
                for (Entry<String, Object> entry : object.entrySet()) {

                    String key = entry.getKey();
                    Map<String, Transition> value = mapTransition(entry.getValue());
                    wf.put(key, value);
                }

            return wf;
        }