BeanUtils.copyProperty的用法问题

我想写一个类，把Database的ResultSet封装一下。用了BeanUtils.copyProperty方法，总是报如下错误：

USING CONVERTER org.apache.commons.beanutils.converters.IntegerConverter@1befab0
java.lang.reflect.InvocationTargetException: Cannot set id
at org.apache.commons.beanutils.BeanUtilsBean.copyProperty(BeanUtilsBean.java:449)
at org.apache.commons.beanutils.BeanUtils.copyProperty(BeanUtils.java:129)


Caused by: java.lang.NoSuchMethodException: Property 'id' has no setter method
at org.apache.commons.beanutils.PropertyUtilsBean.setSimpleProperty(PropertyUtilsBean.java:1746)
at org.apache.commons.beanutils.BeanUtilsBean.copyProperty(BeanUtilsBean.java:447)


可是，UserInfo这个bean里面明明有set方法，而且是public，eclipse总是报错说找不到set方法。

有知道为什么的么？


下面为代码：

/**

 * 

 * @author wcharry

 * 

 */

public class MyDataSet {

	private static Log log = LogFactory.getLog(MyDataSet.class);

	private List list = new ArrayList();



	public MyDataSet(ResultSet rs) {

		try {

			dumpResultSet(rs);

		} catch (SQLException e) {

			e.printStackTrace();

		}

	}



	public MyDataSet(ResultSet rs, Class clazz) {

		try {

			dumpResultSet(rs, clazz);

		} catch (Exception e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}



	public int size() {

		return list.size();

	}



	public Object get(int i) {

		return list.get(i);

	}



	public Object get(int row, int col) {

		HashMap hm = (HashMap) list.get(row);



		Iterator iterator = hm.values().iterator();

		int iCol = 0;

		while (iterator.hasNext()) {

			if (iCol == col)

				return iterator.next();



			iCol++;

		}



		return null;

	}



	public Object get(int row, String key) {

		HashMap hm = (HashMap) list.get(row);



		return hm.get(key);

	}





	private void dumpResultSet(ResultSet rs, Class clazz) throws Exception {

		ResultSetMetaData metaData = (ResultSetMetaData) rs.getMetaData();

		int colCount = metaData.getColumnCount();



		Field[] fields = clazz.getDeclaredFields();



		while (rs.next()) {

			Object newInstance = clazz.newInstance();

			

			for (int i = 1; i <= colCount; i++) {

				try {

					Object value = rs.getObject(i);

					for (int j = 0; j < fields.length; j++) {

						Field f = fields[j];

						if (f.getName().equalsIgnoreCase(

								metaData.getColumnName(i).replaceAll("_", ""))) {



							log.info("f.getName:" + f.getName());



							// 这里总是报错

							BeanUtils.copyProperty(newInstance, f.getName(),

									value);



							log.info("value:" + value);

							break;

						}

					}

				} catch (Exception e) {

					e.printStackTrace();

				}



			}



			list.add(newInstance);

		}

	}



	/**

	 * @param args

	 */

	public static void main(String[] args) {

		String sql = "SELECT * FROM users";

		ResultSet rs = DatabaseFactory.getInstance("mysql").executeQuery(sql);



		MyDataSet ds2 = new MyDataSet(rs, UserInfo.class);



		for (int i = 0; i < ds2.size(); ++i) {

			UserInfo o = (UserInfo) ds2.get(i);

			System.out.println(o.getUser());

		}



		DatabaseFactory.getInstance("mysql").closeConnection();

	}

}







class UserInfo {

	private int id;

	private String user;

	private String password;



	public UserInfo() {

	}



	// public String toString() {

	// return "id:" + id + ", user:" + user;

	// }



	public String getUser() {

		return user;

	}



	public void setUser(String user) {

		this.user = user;

	}



	public String getPassword() {

		return password;

	}



	public void setPassword(String password) {

		this.password = password;

	}



	public int getId() {

		return id;

	}



	public void setId(int id) {

		this.id = id;

	}

}