bookstoreutil.java

dao模式结合mvc,dbcp连接池 log4j日志

package com.bookstore.util;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collection;

import org.apache.log4j.Logger;

import com.bookstore.data.Book;
import com.bookstore.data.BookImpl;

public class BookStoreUtil {
	
	public static Logger log =
		Logger.getLogger(BookStoreUtil.class);
	
	public static void closeConnection(Connection conn)
	{
		if(conn != null)
			try {
				conn.close();
			} catch (SQLException e) {
				log.error("Connection close is Fail.");
				e.printStackTrace();
			}
	}
	
	public static void closeStatement(PreparedStatement ps)
	{
		if(ps != null)
			try {
				ps.close();
			} catch (SQLException e) {
				log.error("PreparedStatement close is Fail.");
				e.printStackTrace();
			}
	}
	
	public static void closeResultSet(ResultSet rs)
	{
		if(rs != null)
			try {
				rs.close();
			} catch (SQLException e) {
				log.error("ResultSet close is Fail.");
				e.printStackTrace();
			}
	}
	
	public static Collection
	makeBookObjectsFromResultSet
	(ResultSet rs) throws SQLException
	{
		Collection result = new java.util.ArrayList();
		while (rs.next())
        {
			  int id = rs.getInt("id");
            String title = rs.getString("title");
            String type = rs.getString("type");
            double price = rs.getDouble("price");
            String notes = rs.getString("notes");
            Book book = new 
            BookImpl(id, title, type, price, notes);
         
            result.add(book);
        }
		return result;
	}
}