Spring used in the project jackson sequence of key object Map

1. Inject ObjectMapper 
2. registered class HistoricTaskInstance serialization and deserialization class HistoricTaskInstanceKeySerializer, HistoricTaskInstanceKeyDeSerializer 
3. Modeule to the new registration in ObjectMapper.

class A { 
　　 //. 1. ObjectMapper injection, ObjectMapper is noted that overall spring. 
    @Autowired 
    Private ObjectMapper ObjectMapper; 
    
    public  void setKeyProcessor () {
 　　　

　　　　SM = new new SimpleModule SimpleModule (); 
　　　　// register serialization, deserialization class. 
　　　　sm.addKeySerializer (HistoricTaskInstance.class, new new HistoricTaskInstanceKeySerializer ()); 
　　　　sm.addKeyDeserializer (HistoricTaskInstance.class, new new HistoricTaskInstanceKeyDeSerializer ()); 
　　　　// registered to ObjectMapper in. 
　　　　objectMapper.registerModule (sm);

 } 
} 

static class HistoricTaskInstanceKeySerializer extends JsonSerializer<HistoricTaskInstance> {
    private final  ObjectMapper objectMapper = new ObjectMapper();
    @Override
    public void serialize(HistoricTaskInstance historicTaskInstance, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
        StringWriter writer = new StringWriter();
        objectMapper.writeValue(writer, historicTaskInstance);
        jsonGenerator.writeFieldName(writer.toString());
    }
}

static class SimpleObjectKeyDeSerializer extends KeyDeserializer {
    private final  ObjectMapper objectMapper = new ObjectMapper();
    @Override
    public HistoricTaskInstance deserializeKey(String key, DeserializationContext deserializationContext) throws IOException {
        return objectMapper.readValue(key, HistoricTaskInstance.class);
    }
}

class HistoricTaskInstance{
　　private String name;
   private String address;
}