Link.java

import org.simpleframework.xml.*;

@Root(name = "link")
@Default(DefaultType.FIELD)
public class Link {
    public static final String ID = "id";
    public static final String TYPE = "type";

    @Text(required = true)
    private String id;
    @Attribute(name = "type", required = true)
    private String type;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Link link = (Link) o;

        if (id != null ? !id.equals(link.id) : link.id != null) return false;
        if (type != null ? !type.equals(link.type) : link.type != null) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = id != null ? id.hashCode() : 0;
        result = 31 * result + (type != null ? type.hashCode() : 0);
        return result;
    }

    @Override
    public String toString() {
        return "Link{" +
                "id='" + id + '\'' +
                ", type='" + type + '\'' +
                '}';
    }
}