如何将DBUtils结果集转换为由更多域对象合成的JavaBean？

我正在Spring框架中创建MVC web应用程序，需要将ApacheDbutils结果集中的行转换为由嵌套对象组成的JavaBean

关于少数几个示例，我发现我创建了这个RowProcessor实现

public class MonthOrderCountHandler extends BasicRowProcessor {

    @Override
    public Object toBean(ResultSet rs, Class type) throws SQLException {

        // Year
        Year year = new Year();
        year.setYearNo(rs.getInt("yearNo"));
        year.setYear4(rs.getString("year4"));
        year.setYear2(rs.getString("year2"));

        // Quarter
        Quarter quarter = new Quarter();
        quarter.setQuarter(rs.getInt("quarter"));

        // Month
        Month m = new Month();
        m.setYear(year);
        m.setQuarter(quarter);
        m.setMonthAbbreviation(rs.getString("monthAbbreviation"));
        m.setMonthName(rs.getString("monthName"));
        m.setMonthNo(rs.getInt("monthNo"));

        // Final bean
        MonthOrderCount result = new MonthOrderCount();
        result.setMonth(m);
        result.setOrderCount(rs.getInt("orderCount"));

        return result;

    }
}

问题：我想知道如何在我的DAO对象中使用这个行处理器，以及这个实现是否正确

---

通常，我会通过以下方式将行转换为JavaBean：

ResultSetHandler<List<MonthOrderCount>> listUrlHandler = new BeanListHandler<>(MonthOrderCount.class);

月班：

public class Month {
    private Quarter quarter;
    private Year year;
    private int monthNo;
    private String monthName;
    private String monthAbbreviation;
}

四分之一班：

public class Quarter {
    private int quarter;
    private String abbreviation;
}

年级：

public class Year {
    private int yearNo;
    private String year2;
    private String year4;
}

编辑：我这样问是因为我的结果如下所示。orderCount变量已正确填充，但在所有实例中月份均为空。但是对我来说最奇怪的是，从来没有调用过toBean（）方法

2013-03-10 17:09:46信息图表数据服务：29- [MonthOrderCount{month=null，orderCount=1863}， MonthOrderCount{month=null，orderCount=2262}， MonthOrderCount{month=null，orderCount=2531}， MonthOrderCount{month=null，orderCount=2379}， MonthOrderCount{month=null，orderCount=2106}， MonthOrderCount{month=null，orderCount=1498}， MonthOrderCount{month=null，orderCount=1300}， MonthOrderCount{month=null，orderCount=1578}， MonthOrderCount{month=null，orderCount=2385}， MonthOrderCount{month=null，orderCount=2991}， MonthOrderCount{month=null，orderCount=2219}， MonthOrderCount{month=null，orderCount=1943}， MonthOrderCount{month=null，orderCount=264}]

---

如果要将resultset转换为JavaBeans列表，则需要重写toBeanList（）而不是toBean（）方法

最终被重写的处理器类如下所示：

public class MonthOrderCountHandler extends BasicRowProcessor {

    @Override
    public List toBeanList(ResultSet rs, Class clazz) {
        try {
            List newlist = new LinkedList();
            while (rs.next()) {
                newlist.add(toBean(rs, clazz));
            }
            return newlist;
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }
    }

    @Override
    public Object toBean(ResultSet rs, Class type) throws SQLException {

        // Year
        Year year = new Year();
        year.setYearNo(rs.getInt("yearNo"));
        year.setYear4(rs.getString("year4"));
        year.setYear2(rs.getString("year2"));

        // Quarter
        Quarter quarter = new Quarter();
        quarter.setQuarterNo(rs.getInt("quarterNo"));

        // Month
        Month m = new Month();
        m.setYear(year);
        m.setQuarter(quarter);
        m.setMonthAbbreviation(rs.getString("monthAbbreviation"));
        m.setMonthName(rs.getString("monthName"));
        m.setMonthNo(rs.getInt("monthNo"));

        // Final bean
        MonthOrderCount result = new MonthOrderCount();
        result.setMonth(m);
        result.setOrderCount(rs.getInt("orderCount"));

        return result;

    }
}

---

我希望它能帮助一些人。

如果要将resultset转换为JavaBeans列表，则需要重写toBeanList（）而不是toBean（）方法

最终被重写的处理器类如下所示：

public class MonthOrderCountHandler extends BasicRowProcessor {

    @Override
    public List toBeanList(ResultSet rs, Class clazz) {
        try {
            List newlist = new LinkedList();
            while (rs.next()) {
                newlist.add(toBean(rs, clazz));
            }
            return newlist;
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }
    }

    @Override
    public Object toBean(ResultSet rs, Class type) throws SQLException {

        // Year
        Year year = new Year();
        year.setYearNo(rs.getInt("yearNo"));
        year.setYear4(rs.getString("year4"));
        year.setYear2(rs.getString("year2"));

        // Quarter
        Quarter quarter = new Quarter();
        quarter.setQuarterNo(rs.getInt("quarterNo"));

        // Month
        Month m = new Month();
        m.setYear(year);
        m.setQuarter(quarter);
        m.setMonthAbbreviation(rs.getString("monthAbbreviation"));
        m.setMonthName(rs.getString("monthName"));
        m.setMonthNo(rs.getInt("monthNo"));

        // Final bean
        MonthOrderCount result = new MonthOrderCount();
        result.setMonth(m);
        result.setOrderCount(rs.getInt("orderCount"));

        return result;

    }
}

我希望它能帮助别人