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() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
int 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() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(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(){
@Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
if(e.getClickCount()>=2){
//取出选择的List
ImageHolder cur=(ImageHolder)imageList.getSelectedValue();
try {
showImage(cur.getId());
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.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 extensions=new ArrayList();
public void addExtension(String extension){
if(!extension.startsWith(".")){
extension="."+extension;
extensions.add(extension.toLowerCase());
}
}
@Override
public boolean accept(File f) {
// TODO Auto-generated method stub
if(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;
}
@Override
public String getDescription() {
// TODO Auto-generated method stub
return 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;
}
@Override
public String toString() {
// TODO Auto-generated method stub
return name;
}
}
- 查看图片附件