使用 Blob 存储 和读取 图片
做个简单 图片上传和浏览的工具
package com.enhance.jdbc.blob;import java.awt.BorderLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.io.File;import java.io.FileInputStream;import java.io.InputStream;import java.sql.Blob;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.Properties;import javax.swing.DefaultListModel;import javax.swing.ImageIcon;import javax.swing.JButton;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JList;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextField;import javax.swing.ListSelectionModel;/* 创建 blob 字段的 表create table img_table(img_id int auto_increment primary key,img_name varchar(255),img_data mediumblob); */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;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();JFileChooser chooser=new JFileChooser(".");ExtensionFileFilter filter=new ExtensionFileFilter();static{try {Properties prop=new Properties();prop.load(new FileInputStream("src/mysql.ini"));String driver=prop.getProperty("driver");String url=prop.getProperty("url");String user=prop.getProperty("user");String pass=prop.getProperty("pass");Class.forName(driver);conn=DriverManager.getConnection(url,user,pass);insert=conn.prepareStatement("insert into img_table(img_name,img_data) values (?,?)",Statement.RETURN_GENERATED_KEYS);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{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);chooser.setAcceptAllFileFilterUsed(false);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() {@Overridepublic void actionPerformed(ActionEvent e) {// TODO Auto-generated method stubint result=chooser.showDialog(jf, "浏览图片文件上传");if(result==JFileChooser.APPROVE_OPTION){filePath.setText(chooser.getSelectedFile().getPath());}}});jp.add(uploadBn);uploadBn.addActionListener(new ActionListener() {@Overridepublic void actionPerformed(ActionEvent e) {// TODO Auto-generated method stubif(filePath.getText().trim().length()>0){upload(filePath.getText());//请客文本框内容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(){@Overridepublic void mouseClicked(MouseEvent e) {// TODO Auto-generated method stubif(e.getClickCount()>=2){//取出选择的ListImageHolder cur=(ImageHolder)imageList.getSelectedValue();try {showImage(cur.getId());} catch (SQLException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}}}});jf.setSize(620,400);jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);jf.setVisible(true);}public void fillListModel() throws SQLException{ResultSet rs=null;try {imageModel.clear();rs=queryAll.executeQuery();while(rs.next()){imageModel.addElement(new ImageHolder(rs.getInt(1),rs.getString(2)));}}finally{if(rs!=null)rs.close();}}public void upload(String fileName){InputStream is=null;try {String imageName=fileName.substring(fileName.lastIndexOf("\")+1,fileName.lastIndexOf("."));insert.setString(1, imageName);File f=new File(fileName);is=new FileInputStream(f);insert.setBinaryStream(2, is,(int)f.length());int affect=insert.executeUpdate();System.out.println(affect);if(affect==1)fillListModel();} catch (Exception e) {e.printStackTrace();}finally{try {if(is!=null)is.close();} catch (Exception e2) {e2.printStackTrace();}}}public void showImage(int id) throws SQLException{ResultSet rs=null;try {query.setInt(1, id);rs=query.executeQuery();if(rs.next()){Blob imageBlob=rs.getBlob(1);imageBlob.getBinaryStream();ImageIcon icon=new ImageIcon(imageBlob.getBytes(1l, (int)imageBlob.length()));imageLabel.setIcon(icon);}}finally{if(rs!=null)rs.close();}}public static void main(String[] args) throws SQLException {new BlobTest().init();}}//-----------------------------package com.enhance.jdbc.blob;import java.io.File;import java.util.ArrayList;import java.util.Iterator;import javax.swing.filechooser.FileFilter;public class ExtensionFileFilter extends FileFilter {private String description="";private ArrayList<String> extensions=new ArrayList<String>();public void addExtension(String extension){if(!extension.startsWith(".")){extension="."+extension;extensions.add(extension.toLowerCase());}}@Overridepublic boolean accept(File f) {// TODO Auto-generated method stubif(f.isDirectory())return true;String name=f.getName().toLowerCase();for (String extension :extensions){if(name.endsWith(extension))return true;}return false;}public void setDescription(String aDescription){description=aDescription;}@Overridepublic String getDescription() {// TODO Auto-generated method stubreturn description;}}//----------------------------------package com.enhance.jdbc.blob;public class ImageHolder {private int id;private String name;public ImageHolder() {super();// TODO Auto-generated constructor stub}public ImageHolder(int id, String name) {super();this.id = id;this.name = name;}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {// TODO Auto-generated method stubreturn name;}}