imagesbrowse.java

图像浏览器,但有些功能尚未实现.用Java编写的打开常见格式的图片程序

import java.io.*; 
import java.util.*; 
import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 
import javax.swing.filechooser.*;//用来打开对话框里指定文件后缀名 
import java.awt.image.*; 
import javax.imageio.*; 
import javax.imageio.ImageIO; 
public class ImagesBrowse extends JFrame implements ActionListener{ 
private JMenuItem jmiOpen = new JMenuItem("打开(O)"); 
private JMenuItem jmiSave = new JMenuItem("保存(S)"); 
private JMenuItem jmiSaveAs = new JMenuItem("另存为(S)"); 
private JMenuItem jmiExit = new JMenuItem("退出(E)"); 

private JMenuItem jmiPrevious = new JMenuItem("上一张(P)"); 
private JMenuItem jmiNext = new JMenuItem("下一张(N)"); 
private JMenuItem jmiZoomOut = new JMenuItem("放大(O)"); 
private JMenuItem jmiZoomIn = new JMenuItem("缩小(I)"); 

private JMenuItem jmiInfo = new JMenuItem("说明(I)"); 
private JMenuItem jmiAbout = new JMenuItem("关于(A)"); 

private JButton jbtPrevious = new JButton("上一张"); 
private JButton jbtNext = new JButton("下一张"); 
private JButton jbtZoomOut = new JButton("放大"); 
private JButton jbtZoomIn = new JButton("缩小"); 
private JButton jbtReset = new JButton("还原"); 
private JFileChooser jfc = new JFileChooser(new File(".")); 
private JLabel jl = new JLabel(); 
private JLabel status = new JLabel("信息提示"); 
public ImagesBrowse(){ 
  JMenu jm1 = new JMenu("文件(F)"); 
  jm1.add(jmiOpen); 
  jm1.add(jmiSave); 
  jm1.add(jmiSaveAs); 
  jm1.addSeparator(); 
  jm1.add(jmiExit); 
  JMenu jm2 = new JMenu("编辑(E)"); 
  jm2.add(jmiPrevious); 
  jm2.add(jmiNext); 
  jm2.add(jmiZoomOut); 
  jm2.add(jmiZoomIn); 
  JMenu jm3 = new JMenu("帮助(H)"); 
  jm3.add(jmiInfo); 
  jm3.add(jmiAbout); 
  JMenuBar jmBar = new JMenuBar(); 
  jmBar.add(jm1); 
  jmBar.add(jm2); 
  jmBar.add(jm3); 
  setJMenuBar(jmBar); 
   
  JPanel jp1 = new JPanel(); 
  jp1.add(jbtPrevious); 
  jp1.add(jbtZoomOut); 
  jp1.add(jbtReset); 
  jp1.add(jbtZoomIn); 
  jp1.add(jbtNext); 
   
  JPanel jp2 = new JPanel(new BorderLayout());   //JPanel的默认布局是FlowLayout 
  jp2.add(new JScrollPane(jl),BorderLayout.CENTER);  //最好不要设置为NORTH,否则jp1的按钮会隐藏 
//     jl.setOpaque(true);     //JLabel默认是透明的,所以直接setBackground()不能设置其背景颜色,但setForceground不用 
//     jl.setBackground(Color.white); 
     jl.setHorizontalAlignment(0); //将jl设置放在中央,不加这句,图片/文字将显示水平靠左,垂直为中间的位置, 
                                         //我也百思不得其解.括号里的数是从0-1的int,alignment的定义 
  jp2.add(jp1,BorderLayout.SOUTH);//将jp1的按钮添加进jp2里 
       
  getContentPane().add(jp2,BorderLayout.CENTER);   
        getContentPane().add(status,BorderLayout.SOUTH); 
   
  jmiOpen.addActionListener(this);//按钮事件 
  jmiSave.addActionListener(this); 
  jmiSaveAs.addActionListener(this); 
  jmiExit.addActionListener(this); 
  jmiInfo.addActionListener(this); 
  jmiAbout.addActionListener(this); 
  jbtPrevious.addActionListener(this); 
  jbtNext.addActionListener(this); 
  jbtZoomOut.addActionListener(this); 
  jbtReset.addActionListener(this); 
  jbtZoomIn.addActionListener(this);   
   
} 
public void actionPerformed(ActionEvent e){ 
   if(e.getSource() == jmiOpen) 
    open(); 
   else if(e.getSource() == jmiSave) 
    save(); 
   else if(e.getSource() == jmiSaveAs) 
    saveAs(); 
   else if(e.getSource() == jmiExit) 
    System.exit(0); 
   else if(e.getSource() == jbtPrevious) 
    previous(); 
      else if(e.getSource() == jbtNext) 
       next(); 
      else if(e.getSource() == jbtZoomOut) 
       zoomOut(); 
      else if(e.getSource() == jbtReset) 
       reset(); 
      else if(e.getSource() == jbtZoomIn) 
       zoomIn(); 
   else if(e.getSource() == jmiInfo){ 
    JOptionPane.showMessageDialog(null,"此程序只能打开下列格式的图像:\n.jpg.bmp.png.gif", 
     "说明",JOptionPane.INFORMATION_MESSAGE); 
   } 
   else if(e.getSource() == jmiAbout){ 
    JOptionPane.showMessageDialog(null,"此程序由牛牛编写.\n2008年11月", 
    "关于",JOptionPane.INFORMATION_MESSAGE); 
   }     
  } 
     
public void open(){ 
  jfc.resetChoosableFileFilters();//将可选择文件过滤器列表重置为其开始状态,不设置的结果会很烦 
  FileNameExtensionFilter filter1 = new FileNameExtensionFilter("PNG Images","png");//设置打开指定后缀名的文件 
  FileNameExtensionFilter filter2 = new FileNameExtensionFilter("GIF Images","gif"); 
  FileNameExtensionFilter filter3 = new FileNameExtensionFilter("BMP Images","bmp"); 
  FileNameExtensionFilter filter4 = new FileNameExtensionFilter("JPG Images","jpg"); 
           jfc.setFileFilter(filter1); 
           jfc.setFileFilter(filter2); 
           jfc.setFileFilter(filter3); 
           jfc.setFileFilter(filter4); 
           
  if(jfc.showOpenDialog(this) == JFileChooser.APPROVE_OPTION){ 
             try{ 
                BufferedImage bi = ImageIO.read(jfc.getSelectedFile()); //Java默认支持的图片类型为jpg,bmp,gif,png 
                ImageIcon icon = new ImageIcon(bi); 
                           
                jl.setIcon(icon);                 // void setIcon(Icon icon) 定义此组件将要显示的图标,API里的JLabel   
       
                long length = jfc.getSelectedFile().length();    //图像文件的大小,在file里定义了此方法 
                int width = bi.getWidth();     //图像的高度 
                int height = bi.getHeight();  //图像的宽度,在JDK API里的BufferedImage有定义,或用ImageIcon里的方法: 
                                              // icon.getIconWidth()和icon.getIconHeight().   
                status.setText("  " + jfc.getSelectedFile().getPath() + " 文件已打开;" + 
                               "      大小: " + length + " bytes;" + 
                               "      分辨率: " + width + " × " + height); 
             } 
            catch(IOException ex){ 
              JOptionPane.showMessageDialog(null,"The image is not supported!", 
                                            "Error",JOptionPane.INFORMATION_MESSAGE); 
              } 
       } 
  } 
public void save(){ 
  try{         
         Icon icon = jl.getIcon(); //从jl中得到图片 
         int width = icon.getIconWidth(); 
           int height = icon.getIconHeight(); 
           BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);//把TYPE_INT_RGB改成TYPE_INT_ARGB图像会变得模糊 
           Graphics g = image.getGraphics(); 
           icon.paintIcon(null, g, 0, 0); 
           
           File output = new File(jfc.getSelectedFile().getPath());//保存替换原图像 
           int info = JOptionPane.showConfirmDialog(null,"是否真的要替换原图像?","提示:",JOptionPane.OK_CANCEL_OPTION,2); 
              if(info == JOptionPane.OK_OPTION)           
                  ImageIO.write(image,"jpg",output);//把image写入output中 
              else 
                  return; 
           
           status.setText("  " + jfc.getSelectedFile().getPath() + " 文件已保存"); 
         } 
         catch(IOException ex){ 
         } 
} 

public void saveAs(){ 
  jfc.resetChoosableFileFilters();//将可选择文件过滤器列表重置为其开始状态 
  FileNameExtensionFilter filter1 = new FileNameExtensionFilter("PNG Images","png"); 
  FileNameExtensionFilter filter2 = new FileNameExtensionFilter("GIF Images","gif"); 
  FileNameExtensionFilter filter3 = new FileNameExtensionFilter("BMP Images","bmp"); 
  FileNameExtensionFilter filter4 = new FileNameExtensionFilter("JPG Images","jpg"); 
           jfc.setFileFilter(filter1); 
           jfc.setFileFilter(filter2); 
           jfc.setFileFilter(filter3); 
           jfc.setFileFilter(filter4); 
  if(jfc.showSaveDialog(this) == JFileChooser.APPROVE_OPTION){ 
               try{     
                Icon icon = jl.getIcon(); //从jl中得到图片 
                int width = icon.getIconWidth(); 
                  int height = icon.getIconHeight(); 
                  BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);//存储后变小了,jdk6里的帮助文件的说明是: 
                  //TYPE_INT_RGB:表示一个图像，它具有合成整数像素的 8 位 RGB 颜色分量。该图像具有不带 alpha 的 DirectColorModel。 
                 //当具有透明 alpha 的数据存储在此类型的图像中时，必须将颜色数据调整为非预乘形式并丢弃 alpha，如 AlphaComposite 文档中的描述。 
                  Graphics g = image.getGraphics(); 
                  icon.paintIcon(null, g, 0, 0); 
                  String str = null;                 
                  if(jfc.getFileFilter() == filter1) //保存时选择格式 
                     str = "png"; 
                  else if(jfc.getFileFilter() == filter2) 
                    str = "gif"; 
                  else if(jfc.getFileFilter() == filter3) 
                    str = "bmp"; 
                  else if(jfc.getFileFilter() == filter4) 
                    str = "jpg"; 
               
               String name = "." + str; 
               File output = null; 
               output = new File(jfc.getSelectedFile().getPath().concat(name));                   
                    status.setText("  " + jfc.getSelectedFile().getPath() + name + " 文件已保存"); 
            //   } 
               //其他1.    String name = jfc.getName(jfc.getSelectedFile());  //获取jfc对话框中的文本框输入的文件名,jfc.getSelectedFile()属于File类型 
              //          File output = new File(name + "." + str);          //指定后缀和输入任意文件名存储在原文件路径中 
             //           ImageIO.write(image,str,output); 
             //其他2.    File output = new File(jfc.getSelectedFile().getPath());     //指定路径,但存储时手动加上后缀名 
             //          ImageIO.write(image,str,output); 
                  if(output.exists()){ 
                           int info = JOptionPane.showConfirmDialog(null,"文件已经存在,是否要覆盖原文件?","提示:",JOptionPane.OK_CANCEL_OPTION,2); 
                           if(info == JOptionPane.OK_OPTION) 
                                ImageIO.write(image,str,output);                //以str格式编码把image写入output中,没有这句的话是无法输出图像文件的 
                           else 
                             return; 
                         } 
                         else 
                            ImageIO.write(image,str,output); 
                } 
               catch(IOException ex){ 
                } 
       } 
}

 public void zoomOut(){ 
     /**      Icon icon = jl.getIcon(); //从jl中得到图片 
         int width = icon.getIconWidth(); 
           int height = icon.getIconHeight(); 
           Image image = this.getToolkit().getImage(jfc.getSelectedFile().getPath()); 
           Image zoomImage=image.getScaledInstance(width*2,height*2,Image.SCALE_DEFAULT); 
           jl.setIcon((Icon)zoomImage); 
                   
               long length = jfc.getSelectedFile().length(); 
                 status.setText("  " + jfc.getSelectedFile().getPath() + " 文件已放大;" + 
                                "      大小: " + length + " bytes" + 
                                "      分辨率: " + width + " × " + height);           
     */
} 

public void zoomIn(){ 

      } 
    public void reset(){ 
    } 
public void previous(){ 
   
} 
public void next(){ 

  }  
   
public static void main(String[] args){ 
ImagesBrowse images = new ImagesBrowse(); 
images.setTitle("图像浏览器"); 
images.setVisible(true); 
images.setSize(1000,800); 
images.setLocation(110,110); 
images.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
} 
}