JSON parse error: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token

Question

I'm using spring boot and and spring data in my project and i have two classes:

@Entity
public class Mission implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue( strategy = GenerationType.IDENTITY )
    private Long              id;
    private String            departure;
    private String            arrival;
    private Boolean           isFreeWayEnabled;
    @OneToMany( mappedBy = "mission" )
    private List<Station>     stations;
    // getters and setters
}

and the second class:

@Entity
public class Station implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue( strategy = GenerationType.IDENTITY )
    private Long              id;
    private String            station;

    @ManyToOne( fetch = FetchType.LAZY )
    @JsonBackReference
    private Mission           mission;
    //getters and setters
}

and the controller:

@RequestMapping( value = "mission/addMission", method = RequestMethod.POST, consumes = "application/json;charset=UTF-8" )
public Reponse addMission( @RequestBody Mission mission ) throws ServletException {
    if ( messages != null ) {
        return new Reponse( -1, messages );
    }
    boolean flag = false;
    try {
        application.addMision( mission );
        application.addStation( mission.getStations(), mission.getId() );
        flag = true;
    } catch ( Exception e ) {
        return new Reponse( 5, Static.getErreursForException( e ) );
    }
    return new Reponse( 0, flag );
}

The problem is when I'm trying to add a new mission with JSON:

{"departure":"fff","arrival":"ffff","isFreeWayEnabled":false,stations:{"id":1}

Answer 1

You are trying to deserialize an object into a list. You need Stations to be JSON array

{"departure":"fff","arrival":"ffff","isFreeWayEnabled":false,stations:[{"id":1}, {"id":2}]}