ResultSetDynaClass与RowSetDynaClass类的应用

1、ResultSetDynaClass 是基于Iterator的，一次只返回一条记录，在ResultSetDynaClass没有操作完以前，ResultSet对象不能关闭。

 

2、RowSetDynaClass是基于List的，一次返回所以的结果。

 

以下是实例代码：

package demo04;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.ResultSetDynaClass;
import org.apache.commons.beanutils.RowSetDynaClass;

/**
 * ResultSetDynaClass类可以包装java.sql.ResultSet类：一次返回一个结果
 * RowSetDnyaClass类包装java.sql.ResultSet：一次性返回所以结果
 */
public class ResultSetDynaClassTest {

	public static void main(String args[]) throws Exception {
		readDBResult();
	}

	public static void readDBResult() throws Exception {
		Connection conn = null;
		ResultSet rs = null;
		PreparedStatement pstmt = null;

		try {
			Class.forName("com.mysql.jdbc.Driver");
			String url = "jdbc:mysql://localhost:3306/study?useUnicode=true&characterEncoding=GBK";
			String username="root";
			String password = "root";
			conn = DriverManager.getConnection(url,username, password);
			pstmt = conn.prepareStatement("select id,username, password from user");
			rs = pstmt.executeQuery();
			
			//使用java.sql.ResultSet输出
			while(rs.next()) {
				System.out.println("username=" + rs.getString("username"));
			}
			
			//使用Common BeanUtils中的ResultSetDynaClass类包装
			System.out.println("-----------分割线---------------------");
			rs.beforeFirst();//这里必须使用beforeFirst
			ResultSetDynaClass rsdc = new ResultSetDynaClass(rs);
			Iterator<DynaBean> rows = rsdc.iterator();
			while(rows.hasNext()) {
				DynaBean row = rows.next();
				System.out.println("id=" + row.get("id") + ",username=" 
						+ row.get("username") + ",password="
						+ row.get("password"));
			}
			
			//使用RowSetDnyaClass类
			System.out.println("-----------分割线---------------------");
			rs.beforeFirst();//这里必须使用beforeFirst
			RowSetDynaClass rc = new RowSetDynaClass(rs);
			List<DynaBean> resultList = rc.getRows();
			for(DynaBean db : resultList) {
				System.out.print(db.get("id") + "\t");
				System.out.print(db.get("username") + "\t");
				System.out.println(db.get("password"));
			}
		} finally {
			if(pstmt!=null)
				pstmt.close();
			if(rs!=null)
				rs.close();
			if(conn!=null)
				conn.clearWarnings();
		}
	}
}