@JsonRootName不起作用

时间:2016-03-19 21:45:04

标签: json java-ee jackson

我有这个简单的Java实体,我需要将它作为JSon输出,我可以通过e web服务获得。

@Entity
@JsonRootName(value = "flights")
public class Flight implements Serializable {

@Transient
private static final long serialVersionUID = 1L;

public Flight() {
    super();
}

public Flight(FlightDestination destinationFrom, FlightDestination destinationTo, Integer flightPrice, Date date,
        Airplane airplaneDetail) {
    super();
    this.destinationFrom = destinationFrom;
    this.destinationTo = destinationTo;
    this.flightPrice = flightPrice;
    this.date = date;
    this.airplaneDetail = airplaneDetail;
}

public Flight(FlightDestination destinationFrom, FlightDestination destinationTo, Integer flightPrice, Date date) {
    super();
    this.destinationFrom = destinationFrom;
    this.destinationTo = destinationTo;
    this.flightPrice = flightPrice;
    this.date = date;
}

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;

@Enumerated(EnumType.STRING)
private FlightDestination destinationFrom;

@Enumerated(EnumType.STRING)
private FlightDestination destinationTo;

private Integer flightPrice;

@Temporal(TemporalType.DATE)
private Date date;

@OneToOne(cascade = { CascadeType.PERSIST, CascadeType.REMOVE })
@JoinColumn(name = "airplane_fk")
private Airplane airplaneDetail;}

我添加了@JsonRootName,但我仍然以这种方式得到了我的json输出:

    [  
      {   

      },

      { 

      }
   ]

我还需要添加到我的实体中,最后才能获得这种输出:

    {
     "flights":

     [  

      {   

      },

      { 

      }
    ]
   }

1 个答案:

答案 0 :(得分:3)

如果您想使用@JsonRootName(value = "flights"),则必须在ObjectMapper上设置适当的功能

ObjectMapper mapper = new ObjectMapper();
mapper.enable(DeserializationFeature.UNWRAP_ROOT_VALUE); 
mapper.enable(SerializationFeature.WRAP_ROOT_VALUE);

但是,对于List<Flight>,这将产生

[  
  {"flights": {}},
  {"flights": {}},
  {"flights": {}},
]

所以你可能需要创建包装器对象:

public class FlightList {
    @JsonProperty(value = "flights")
    private ArrayList<Flight> flights;
}

FlightList{"flights":[{ }, { }]}输出json