如何在jrxml中显示表列表

Question

我必须在jasper报告中显示几个表。列表的大小仅在运行时已知。如何实现？

示例：

标题1

Column1 Column2 Column3

Value1 Value2 Value3

标题2

Column1 Column2 Column3

Value1 Value2 Value2

要显示的数据如下： 表格的每一行都由以下类别的对象表示：

public class ReservationDTO {

    private static final long serialVersionUID = 1L;

    /**
     * Constant representing the name of the automatic primary key field.
     */
    public static final String PROP_ID = "_id";
    private Long _id;


    private java.util.Date startHour;

    private java.util.Date endHour;

    private String company;

    public java.util.Date getStartHour() {
        return startHour;
    }

    public void setStartHour(java.util.Date startHour) {
        this.startHour = startHour;
    }

    public Date getEndHour() {
        return endHour;
    }

    public void setEndHour(Date endHour) {
        this.endHour = endHour;
    }

    public String getCompany() {
        return company;
    }

    public void setCompany(String company) {
        this.company = company;
    }
}

表的标题是从类中检索的：

import java.util.Set;

public class RoomReservationDTO  {
    private static final long serialVersionUID = 1L;

    /**
     * Constant representing the name of the automatic primary key field.
     */

    Set<ReservationDTO> reservations;
    String roomName;
    public Set<ReservationDTO> getReservations() {
        return reservations;
    }
    public void setReservations(Set<ReservationDTO> reservations) {
        this.reservations = reservations;
    }
    public String getRoomName() {
        return roomName;
    }
    public void setRoomName(String roomName) {
        this.roomName = roomName;
    }

}

该报告是通过以下方法创建的，其中ReservationList是一个列表

private static JasperPrint createReport( Collection<?> reservationList, String templatePath )
{
    JasperPrint jasperPrint = null;
    File report = new File( templatePath );

    Map<String, Object> params = new HashMap<>( );

    try
    {
        jasperPrint = JasperFillManager.fillReport( report.getAbsolutePath( ), params, new JRBeanCollectionDataSource( reservationList ) );
    }
    catch( JRException e )
    {

    }
    return jasperPrint;

}