一個簡單Swing程序的架構

Java Swing程序不像J2EE程序那樣有框架有模式可遵，反倒顯得很自由無所拘束，但如些一來反而顯得程序代碼雜亂無章，如果只是寫個示例程序的話倒也無所謂，但隨着代碼的增多或過段時間在回首時就發現代碼很不容易看懂，不以維護。我雖無大型Swing程序的經驗，但平素喜愛用Swing寫寫工具程序以練練手，因此我以下是我的經驗總結。下面以些圖來表示

一個桌面級程序必然是以一個主界面展開的，在Swing中這個主界面是派生自JFrame的，其中有菜單、工具欄、狀態欄、內容面板（contentPanel）和一些相應的按鈕，這些界面元素即可以派生自某個類或調用Swing的現成類，但最後總要添加到界面中，而爲了與用戶交互，控件要和一個實現了Action接口的類綁定，因此在界面層中我分別實例化了ActionsManager和Functions對象，我專門寫了一個ActionsManager類的用以管理程序中所有的Action接口的類，通過鍵值對集合把某個控件的動作與相應的控件綁定，當然你可能會覺得這很無聊，還不如在構造控件時直接將動作與之綁定就可以了，但這樣做時很沒有重複性，如果某個動作即要被按鈕實現又要被菜單實現，還要被工具欄實現的話就要重複寫三次代碼，如果還要考慮其禁用與否就更麻煩了，因此我乾脆將動作類統統封裝在一個集合中統一調用，比如如下的代碼
public class LoginActions { private MainPanel mainPanel; private LoginManager loginManager; private Map<String,LoginAction> mapActions; public LoginActions() { mapActions = new HashMap<String,LoginAction>(); new LoginAction("新建(N)","image/newfile.gif","image/tbnew.png",KeyEvent.VK_N,"ctrl N","new"){ public void actionPerformed(ActionEvent e) { mainPanel.newFile(); } }; new LoginAction("打開(O)...","image/open.gif","image/tbopen.png",KeyEvent.VK_O,"ctrl O","open"){ public void actionPerformed(ActionEvent e) { mainPanel.openFromFile(); } }; new LoginAction("保存(S)","image/save.gif","image/tbsave.png",KeyEvent.VK_S,"ctrl S","save"){ public void actionPerformed(ActionEvent e) { if(loginManager.isModifyFlag()) mainPanel.saveToFile(false); } }; new LoginAction("另存爲(A)...",null,null,KeyEvent.VK_A,null,"saveas"){ public void actionPerformed(ActionEvent e) { if(loginManager.isModifyFlag()) mainPanel.saveToFile(true); } }; new LoginAction("導出(E)...",null,"image/tbexport.png",KeyEvent.VK_E,null,"export"){ public void actionPerformed(ActionEvent e) { mainPanel.exprotFile(); } }; new LoginAction("退出(X)",null,"image/tbexit.png",KeyEvent.VK_X,"ctrl alt X","exit"){ public void actionPerformed(ActionEvent e) { mainPanel.ExitApplication(); } }; new LoginAction("複製(C)","image/copy.gif",null,KeyEvent.VK_C,"ctrl C","copy"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.editMenuCopy(); } }; new LoginAction("粘貼(P)","image/paste.gif",null,KeyEvent.VK_P,"ctrl V","paste"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.editMenuPaste(); } }; new LoginAction("剪切(X)","image/cut.gif",null,KeyEvent.VK_X,"ctrl X","cut"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.editMenuCut(); } }; new LoginAction("清除輸入(R)",null,null,KeyEvent.VK_R,null,"reinput"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.resetInput(); } }; new LoginAction("新增分類(A)",null,null,KeyEvent.VK_A,null,"addType"){ public void actionPerformed(ActionEvent e) { mainPanel.showTypeDlg(true); } }; new LoginAction("刪除分類(D)",null,null,KeyEvent.VK_D,null,"delType"){ public void actionPerformed(ActionEvent e) { mainPanel.deleteType(); } }; new LoginAction("修改分類(M)",null,null,KeyEvent.VK_M,null,"modifyType"){ public void actionPerformed(ActionEvent e) { mainPanel.showTypeDlg(false); } }; new LoginAction("新增記錄(D)",null,null,KeyEvent.VK_D,null,"addLogin"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.addLogin(); } }; new LoginAction("刪除記錄(E)",null,null,KeyEvent.VK_E,null,"delLogin"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.deleteLogin(); } }; new LoginAction("修改記錄(O)",null,null,KeyEvent.VK_O,null,"modifyLogin"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.modifyLogin(); } }; new LoginAction("查找(F)","image/tbfind.png",null,KeyEvent.VK_F,null,"findLogin"){ public void actionPerformed(ActionEvent e) { mainPanel.rightPanel.find(); } }; new LoginAction("轉至地址(L)",null,null,KeyEvent.VK_L,null,"goURL"){ public void actionPerformed(ActionEvent e) { mainPanel.bottomPanel.goUrl(); } }; new LoginAction("刷新(U)","image/refresh.gif","image/tbudpate.png",KeyEvent.VK_U,null,"refresh"){ public void actionPerformed(ActionEvent e) { mainPanel.updatePanelUI(); } }; new LoginAction("程序設置(S)...","image/setup.gif","image/tbOption.png",KeyEvent.VK_S,null,"setup"){ public void actionPerformed(ActionEvent e) { mainPanel.showSetupDlg(); } }; new LoginAction("關於(A)...","image/about.gif","image/tbHelp.png",KeyEvent.VK_A,null,"about"){ public void actionPerformed(ActionEvent e) { mainPanel.showAboutDlg(); } }; } public Action getAction(String command) { return mapActions.get(command); } public void setMainPanel(MainPanel mainPanel) { this.mainPanel = mainPanel; } public void setLoginManager(LoginManager loginManager) { this.loginManager = loginManager; } abstract class LoginAction extends AbstractAction{ public LoginAction(String name,String icon,String bigIcon,int memKey,String stroke,String command) { this.putValue(NAME, name); if(icon!=null) this.putValue(Action.SMALL_ICON, new ImageIcon(this.getClass().getClassLoader().getResource(icon))); else this.putValue(Action.SMALL_ICON, new ImageIcon(this.getClass().getClassLoader().getResource("image/mnuNullIcon.gif"))); if(bigIcon!=null) this.putValue(Action.LARGE_ICON_KEY, new ImageIcon(this.getClass().getClassLoader().getResource(bigIcon))); if(memKey!=0) this.putValue(Action.MNEMONIC_KEY, memKey); if(stroke!=null) this.putValue(Action.ACCELERATOR_KEY, KeyStroke.getKeyStroke(stroke)); this.putValue("command", command); mapActions.put(command, this); } } }
然後在所有的控件容器類中實現相關的功能，讓ActionsManager類的相應Action接口類來調用即可，而將界表示層和業務邏輯層分離已是衆所皆知的道理，因此在ActionsManager內的主界面對象實例可以訪問界面的UI Manager方法集，由UI Manager再調用相應的業務邏輯層，即Functions內的方法，並把結果返回至UI Manager，以此來實現動作層、表示層和業務層的簡單框架。