blobtest.java

疯狂Java讲义_源码(含Java设计模式CHM

import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Properties;
import java.util.ArrayList;
import java.io.*;
import javax.swing.filechooser.FileFilter;

/**
 * Description:
 * <br/>Copyright (C), 2005-2008, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee [e-mail]
 * @version  1.0
 */
public class BlobTest
{
	JFrame jf = new JFrame("图片管理程序");
	private static Connection conn;
	private static PreparedStatement insert;
	private static PreparedStatement query;
	private static PreparedStatement queryAll;

	//定义一个DefaultListModel对象
	private DefaultListModel imageModel = new DefaultListModel();
	private JList imageList = new JList(imageModel);
	private JTextField filePath = new JTextField(26);
	private JButton browserBn = new JButton("...");
	private JButton uploadBn = new JButton("上传");
	private JLabel imageLabel = new JLabel();
	//以当前路径创建文件选择器
	JFileChooser chooser = new JFileChooser(".");
	//创建文件过滤器
	ExtensionFileFilter filter = new ExtensionFileFilter();
	static
	{
		try
		{
			Properties props = new Properties();
			props.load(new FileInputStream("mysql.ini"));
			String driver = props.getProperty("driver");
			String url = props.getProperty("url");
			String user = props.getProperty("user");
			String pass = props.getProperty("pass");
			Class.forName(driver);
			//获取数据库连接
			conn = DriverManager.getConnection(url , user , pass);
			//创建执行插入的PreparedStatement对象，该对象执行插入后可以返回自动生成的主键
			insert = conn.prepareStatement("insert into img_table values(null,?,?)"
				, Statement.RETURN_GENERATED_KEYS);
			//创建两个PreparedStatement对象，用于查询指定图片，查询所有图片
			query = conn.prepareStatement("select img_data from img_table where img_id=?");
			queryAll = conn.prepareStatement("select img_id,img_name from img_table");
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}

	public void init()throws SQLException
	{
		//-------初始化文件选择器--------
		filter.addExtension("jpg");
		filter.addExtension("jpeg");
		filter.addExtension("gif");
		filter.addExtension("png");
		filter.setDescription("图片文件(*.jpg,*.jpeg,*.gif,*.png)");
		chooser.addChoosableFileFilter(filter);
		//禁止“文件类型”下拉列表中显示“所有文件”选项。
		chooser.setAcceptAllFileFilterUsed(false); 
		//---------初始化程序界面---------
		fillListModel();
		filePath.setEditable(false);
		//只能单选
		imageList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
		JPanel jp = new JPanel();
		jp.add(filePath);
		jp.add(browserBn);
		browserBn.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				//显示文件对话框
				int result = chooser.showDialog(jf , "浏览图片文件上传");
				//如果用户选择了APPROVE（赞同）按钮，即打开，保存及其等效按钮
				if(result == JFileChooser.APPROVE_OPTION)
				{
					filePath.setText(chooser.getSelectedFile().getPath());
				}
			}
		});
		jp.add(uploadBn);
		uploadBn.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent avt)
			{
				//如果上传文件的文本框有内容
				if (filePath.getText().trim().length() > 0)
				{
					//将指定文件保存到数据库
					upload(filePath.getText());
					//清空文本框内容
					filePath.setText("");
				}
			}
		});
		JPanel left = new JPanel();
		left.setLayout(new BorderLayout());
		left.add(new JScrollPane(imageLabel) , BorderLayout.CENTER);
		left.add(jp , BorderLayout.SOUTH);
		jf.add(left);
		imageList.setFixedCellWidth(160); 
		jf.add(new JScrollPane(imageList) , BorderLayout.EAST);
		imageList.addMouseListener(new MouseAdapter()
		{
			public void mouseClicked(MouseEvent e)
			{
				//如果鼠标双击
				if (e.getClickCount() >= 2)
				{
					//取出选中的List项
					ImageHolder cur = (ImageHolder)imageList.getSelectedValue();
					try
					{
						//显示选中项对应的Image
						showImage(cur.getId());
					}
					catch (SQLException sqle)
					{
						sqle.printStackTrace();
					}
				}
			}
		});
		jf.setSize(620, 400);
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		jf.setVisible(true);	
	}
	//----------查找img_table填充ListModel----------
	public void fillListModel()throws SQLException
	{
		ResultSet rs = null;
		try
		{
			//先清除所有元素
			imageModel.clear();
			//执行查询
			rs = queryAll.executeQuery();
			//把查询的全部记录添加到ListModel中
			while (rs.next())
			{
				imageModel.addElement(new ImageHolder(rs.getInt(1),
					rs.getString(2)));
			}
		}
		finally
		{
			if (rs != null)
			{
				rs.close();
			}
		}
	}
	//---------将指定图片放入数据库---------
	public void upload(String fileName)
	{
		InputStream is = null;
		try
		{
			//截取文件名
			String imageName = fileName.substring(
				fileName.lastIndexOf('\\') + 1 , fileName.lastIndexOf('.'));
			//设置图片名参数
			insert.setString(1, imageName);
			File f = new File(fileName);
			is = new FileInputStream(f);
			//设置二进制流参数
			insert.setBinaryStream(2, is , (int)f.length());
			int affect = insert.executeUpdate();
			if (affect == 1)
			{
				//重新更新ListModel，将会让JList显示最新的图片列表
				fillListModel();
			}
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
		finally
		{
			try
			{
				if (is != null)
				{
					is.close();
				}	
			}
			catch (Exception e)
			{
			}
		}
	}
	//---------根据图片ID来显示图片----------
	public void showImage(int id)throws SQLException
	{
		ResultSet rs = null;
		try
		{
			//设置参数
			query.setInt(1, id);
			//执行查询
			rs = query.executeQuery();
			if (rs.next())
			{
				//取出Blob列
				Blob imgBlob = rs.getBlob(1);
				//取出Blob列里的数据
				ImageIcon icon = new ImageIcon(imgBlob.getBytes(1L , (int)imgBlob.length()));
				imageLabel.setIcon(icon);
			}
		}
		finally
		{
			if (rs != null)
			{
				rs.close();
			}
		}
	}

	public static void main(String[] args)throws SQLException
	{
		new BlobTest().init();
	}
}
//创建FileFilter的子类，用以实现文件过滤功能
class ExtensionFileFilter extends FileFilter
{

	private String description = "";
	private ArrayList<String> extensions = new ArrayList<String>();
	//自定义方法，用于添加文件扩展名
	public void addExtension(String extension)
	{
		if (!extension.startsWith("."))
		{
			extension = "." + extension;
			extensions.add(extension.toLowerCase());
		}
	}
	//用于设置该文件过滤器的描述文本
	public void setDescription(String aDescription)
	{
		description = aDescription;
	}
	//继承FileFilter类必须实现的抽象方法，返回该文件过滤器的描述文本
	public String getDescription()
	{
		return description; 
	}
	//继承FileFilter类必须实现的抽象方法，判断该文件过滤器是否接受该文件
	public boolean accept(File f)
	{
		//如果该文件是路径，接受该文件
		if (f.isDirectory()) return true;
		//将文件名转为小写（全部转为小写后比较，用于忽略文件名大小写）
		String name = f.getName().toLowerCase();
		//遍历所有可接受的扩展名，如果扩展名相同，该文件就可接受。
		for (String extension : extensions)
		{
			if (name.endsWith(extension)) 
			{
				return true;
			}
		}
		return false;
	}
}
//创建一个ImageHolder类，用于封装图片名、图片ID
class ImageHolder
{
	//封装图片的ID
	private int id;
	//封装图片的图片名字
	private String name;

	public ImageHolder()
	{
	}

	public ImageHolder(int id , String name)
	{
		this.id = id;
		this.name = name;
	}

	public void setId(int id)
	{
		this.id = id;
	}
	public int getId()
	{
		 return this.id;
	}

	public void setName(String name)
	{
		this.name = name;
	}
	public String getName()
	{
		 return this.name;
	}
	//重写toString方法，返回图片名
	public String toString()
	{
		return name;
	}
}