java编程一

Dao类：
package cn.edu.tzc.dao;
import java.sql.*;
import java.util.ArrayList;
import cn.edu.tzc.bean.books;
public class BookDao {
  public ArrayList queryAllBooks ()throws Exception{
	  Connection conn=null;
	  ArrayList books=new ArrayList();
	try{
		Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		 conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433; DatabaseName=books","sa","123456");
		 Statement stat = conn.createStatement();
		 String sql="SELECT * FROM T_BOOK";
		 ResultSet rs=stat.executeQuery(sql);
		 while(rs.next()){
			 books book1=new books();
			 book1.setId(rs.getString("Id"));
			 book1.setName(rs.getString("Name"));
			 book1.setPrice(rs.getString("Price"));
			 books.add(book1);
		 }
		 rs.close();
		 stat.close();
		
	}
	catch(Exception e){
		e.printStackTrace();
	}finally{
		if(conn!=null)
		{
			conn.close();
			conn=null;
		}
	}
	return books;
}
}
Dao类：
package cn.edu.tzc.