package viewer;import java.awt.BorderLayout;import java.awt.Dimension;import java.awt.FlowLayout;import java.awt.Image;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.File;import java.util.ArrayList;import javax.swing.AbstractAction;import javax.swing.ImageIcon;import javax.swing.JButton;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JMenu;import javax.swing.JMenuBar;import javax.swing.JMenuItem;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JToolBar;import javax.swing.filechooser.FileFilter;interface Action{void execute(V iewerService service,V iewerFrame frame);}public class V iewer {public static void main(String[] args) {// TODO code application logic hereV iewerFrame f = new V iewerFrame();f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);}}class ViewerFrame extends JFrame//主界面类{private int width = 800;private int height = 600;private JLabel label = new JLabel();V iewerService service = new V iewerService();public V iewerFrame(){super();init();}ActionListener menuListener = new ActionListener(){public void actionPerformed(ActionEvent e){service.menuDo(V iewerFrame.this ,e.getActionCommand());}};public void createMenuBar()//创建文件、工具、帮助菜单{JMenuBar menuBar = new JMenuBar();String[] menuArr = { "文件（F）","工具（T）","帮助（H）"};String[][] menuItemArr ={{"打开（O）","-","退出（X）"},{"放大（M）","缩小（O）","-","上一个（X）","下一个（P）"},{"帮助主题","关于"}};for(int i = 0; i < menuArr.length;i++){JMenu menu = new JMenu(menuArr[i]);for(int j = 0;j < menuItemArr[i].length;j++){if(menuItemArr[i][j].equals("-"))menu.addSeparator();else{JMenuItem menuItem = new JMenuItem(menuItemArr[i][j]);menuItem.addActionListener(menuListener);menu.add(menuItem);}}menuBar.add(menu);}this.setJMenuBar(menuBar);}void init()//初始化界面{this.setTitle("看图程序");this.setPreferredSize(new Dimension(width,height));createMenuBar();JPanel toolBar = createToolPanel();this.add(toolBar,BorderLayout.NORTH);this.add(new JScrollPane(label),BorderLayout.CENTER);this.setV isible(true);this.pack();}JLabel getLabel()//获取显示图片的JLabel{return bel;}JPanel createToolPanel()//创建放大、缩小、上一张、下一张等工具按钮{JPanel panel = new JPanel();JToolBar toolBar = new JToolBar("工具");toolBar.setFloatable(false);panel.setLayout(new FlowLayout( FlowLayout.LEFT));//org.crazyit.viewer.action.String[] toolarr = {"viewer.OpenAction","stAction","viewer.NextAction","viewer.BigAction","viewer.SmallAction"};for(int i =0; i < toolarr.length;i++){V iewerAction action = new V iewerAction(new ImageIcon("img/"+toolarr[i]+".gif"),toolarr[i],this);JButton button = new JButton(action);toolBar.add(button);}panel.add(toolBar);return panel;}}class ViewerFileChooser extends JFileChooser{private void addFilter()this.addChoosableFileFilter(new MyFileFilter(new String[]{".BMP"},"BMP (*.BMP)"));this.addChoosableFileFilter(new MyFileFilter(new String[]{".JPG",".JPEG",".JPE",".JFIF"},"JPEG (*.JPG;*.JPEG;*.JPE;*.JFIF)"));this.addChoosableFileFilter(new MyFileFilter(new String[]{".GIF"},"GIF (*.GIF)"));this.addChoosableFileFilter(new MyFileFilter(new String[]{".TIF",".TIFF"},"TIFF (*.TIF;*.TIFF)"));this.addChoosableFileFilter(new MyFileFilter(new String[]{".PNG"},"PNG (*.PNG)"));this.addChoosableFileFilter(new MyFileFilter(new String[]{".ICO"},"ICO (*.ICO)"));this.addChoosableFileFilter(new MyFileFilter(new String[]{".BMP",".JPG",".JPEG",".JPE",".JFIF",".GIF","TIF",".TIFF",".PNG",".ICO"},"所有图形文件"));}public V iewerFileChooser(){super();setAcceptAllFileFilterUsed(false);addFilter();}class MyFileFilter extends FileFilter{String[] suffarr;String description;public MyFileFilter(String[] suffarr,String description){super();this.suffarr = suffarr;this.description = description;}public boolean accept(File file){for(String s:suffarr){if(file.getName().toUpperCase().endsWith(s))return true;}return file.isDirectory();}@Overridepublic String getDescription() {return this.description;}}class ViewerService //业务处理类{private static V iewerService service = null;private V iewerFileChooser fileChooser = new ViewerFileChooser();private File currentFile = null;private File currentDirectory = null;private ArrayList<File> currentFiles = null;private double range = 0.1;private boolean isIcon = true;private ImageIcon icon = null;private double enLargeRange = 1;static V iewerService getInstance(){if (service == null) {service = new V iewerService();}return service;}void open(V iewerFrame frame){if(fileChooser.showOpenDialog(frame) == V iewerFileChooser.APPROVE_OPTION)//给打开的文件赋值{this.currentFile = fileChooser.getSelectedFile();String name = this.currentFile.getPath();File cd = fileChooser.getCurrentDirectory();if(cd != this.currentDirectory || this.currentDirectory == null){FileFilter[] fileFilters = fileChooser.getChoosableFileFilters();File files[] = cd.listFiles();this.currentFiles = new ArrayList<File>();for(File file: files){if(!file.isHidden())for(FileFilter filter : fileFilters){if(filter.accept(file)){this.currentFiles.add(file);break;}}}ImageIcon icon = new ImageIcon(name);frame.getLabel().setIcon(icon);}}void zoom(V iewerFrame frame,boolean isEnlarge){if(enLargeRange > 0.2)enLargeRange = isEnlarge ? enLargeRange + range :enLargeRange -range;elseif(isEnlarge)enLargeRange = enLargeRange + range ;if(isIcon||icon == null){icon = (ImageIcon)frame.getLabel().getIcon();isIcon = false;}if(icon != null){int width = (int)(icon.getIconWidth() * enLargeRange);int height = (int)(icon.getIconHeight() * enLargeRange);ImageIcon newIcon = new ImageIcon(icon.getImage().getScaledInstance(width, height, Image.SCALE_DEFAULT));frame.getLabel().setIcon(newIcon);}}void last(ViewerFrame frame){if(this.currentFiles != null && !this.currentFiles.isEmpty()){isIcon = true;File file;ImageIcon icon ;int index = this.currentFiles.indexOf(this.currentFile);if(index > 0){file = (File)this.currentFiles.get(index-1);icon = new ImageIcon(file.getPath());frame.getLabel().setIcon(icon);this.currentFile = file;}elseif(index == 0)file = (File)this.currentFiles.get(currentFiles.size()-1);icon = new ImageIcon(file.getPath());frame.getLabel().setIcon(icon);this.currentFile = file;}}}void next(V iewerFrame frame){if(this.currentFiles != null && !this.currentFiles.isEmpty()){isIcon = true;File file;ImageIcon icon ;int index = this.currentFiles.indexOf(this.currentFile);if(index < currentFiles.size()-1){file = (File)this.currentFiles.get(index+1);icon = new ImageIcon(file.getPath());frame.getLabel().setIcon(icon);this.currentFile = file;}elseif(index == currentFiles.size()-1){file = (File)this.currentFiles.get(0);icon = new ImageIcon(file.getPath());frame.getLabel().setIcon(icon);this.currentFile = file;}}}void menuDo(V iewerFrame frame,String cmd){if(cmd.equals("打开（O）"))open(frame);if(cmd.equals("放大（M）"))zoom(frame,true);if(cmd.equals("缩小（O）"))zoom(frame,false);if(cmd.equals("上一个（X）"))last(frame);if(cmd.equals("退出(X)"))System.exit(0);}}class ViewerAction extends AbstractAction{private Action action = null;private V iewerFrame frame = null;private String actionName= "";public V iewerAction(ImageIcon icon,String actionName,ViewerFrame frame){super("",icon);this.frame = frame;this.actionName = actionName;}private Action getAction(String actionName){try{if(this.action == null){Action action = (Action)Class.forName(actionName).newInstance();this.action = action;}return this.action;}catch(Exception e){return null;}}public void actionPerformed(ActionEvent ae){V iewerService service = V iewerService.getInstance();Action action = getAction(this.actionName);action.execute(service, frame);}}class OpenAction implements Action{public void execute(ViewerService service, V iewerFrame frame){service.open(frame);}}class NextAction implements Action{@Overridepublic void execute(ViewerService service, V iewerFrame frame){service.next(frame);}}class LastAction implements Action{public void execute(ViewerService service, V iewerFrame frame){st(frame);}}class BigAction implements Action{@Overridepublic void execute(ViewerService service, V iewerFrame frame){service.zoom(frame, true);}}class SmallAction implements Action{@Overridepublic void execute(ViewerService service, V iewerFrame frame) {service.zoom(frame, false);}}各图片命名按顺序如下：del viewer.BigAction stAction viewer.NextAction viewer.OpenAction viewer.SmallActionPS：代码参考自疯狂java。
