javaBean属性为对象时赋值问题

[lazy_yy]

public class Dishe {
	private String did;
	private String dname;
	private double price;
	private Category category;
}

public class Category {
	private String cid;
	private String cname;
}

public List<Dishe> findByCategoryList(String cid) {
		String sql = "SELECT * FROM dishes WHERE cid=?";
		try {
			List<Dishe> disheList = qr.query(sql, new BeanListHandler<Dishe>(
					Dishe.class), cid);
			for (Dishe dishe : disheList) {
				loadCategory(dishe);
				System.out.println(dishe);
			}
			return disheList;
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}

	private void loadCategory(Dishe dishe) {
		String sql = "SELECT * FROM dishes d,category c WHERE d.cid=c.cid AND did=?";
		try {
			Map<String, Object> map = qr.query(sql, new MapHandler(),
					dishe.getDid());
			toCategory(map);

		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}

	private void toCategory(Map<String, Object> map) {
		Dishe dishe = CommonUtils.toBean(map, Dishe.class);  //传个map转换为对象
		Category category = CommonUtils.toBean(map, Category.class);
		dishe.setCategory(category);
	}

我通过findByCategoryList() 这个方法查询返回一个List<Dishe>集合， 但是Dishe里面的Category对象为空 我测试的时候分开调用这三个方法，Category的有值的对象就可以set到Dishe里 没发现问题在哪，求解决。。。

[我自横刀香甜笑]

private void loadCategory(Dishe dishe) { String sql = "SELECT * FROM dishes d,category c WHERE d.cid=c.cid AND did=?"; try { Map<String, Object> map = qr.query(sql, new MapHandler(), dishe.getDid()); Category category = CommonUtils.toBean(map, Category.class); dishe.setCategory(category); } catch (SQLException e) { throw new RuntimeException(e); } } 试试这样吧。你已经中间把dishe对象换过了，，，，保存到别的对象里了。。。

[wcwtitxu]

public List<Dishe> findByCategoryList(String cid) {
	String sql = "SELECT * FROM dishes WHERE cid=?";
	try {
		List<Dishe> disheList = qr.query(sql, new BeanListHandler<Dishe>(
				Dishe.class), cid);
		for (Dishe dishe : disheList) {
			loadCategory(dishe);
			System.out.println(dishe);
		}
		return disheList;
	} catch (SQLException e) {
		throw new RuntimeException(e);
	}
}

private void loadCategory(Dishe dishe) {
	String sql = "SELECT * FROM dishes d,category c WHERE d.cid=c.cid AND did=?";
	try {
		Map<String, Object> map = qr.query(sql, new MapHandler(),
				dishe.getDid());
		dishe.setCategory( toCategory(map) );
	} catch (SQLException e) {
		throw new RuntimeException(e);
	}
}

private void toCategory(Map<String, Object> map) {
	return CommonUtils.toBean(map, Category.class);
}