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Design Pattern: Abstract Factory 模式
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轉載請注明出處:https://blog.csdn.net/wdzxl198/article/details/9219421；
文章摘自： https://www.riabook.cn/doc/designpattern/；
- CustomDialog.java
1: public class CustomDialog {
2: private IButton button;
3: private ITextField textField;
4:
5: public void setButton(IButton button) {
6: this.button = button;
7: }
8:
9: public void setTextField(ITextField textField) {
10: this.textField = textField;
11: }
12:
13: public void layoutAllComponents() {
14: // ....
15: }
16:
17: public void showDialog() {
18: this.paintDialog();
19: button.paintButton();
20: textField.paintTextField();
21: }
22:
23: public void paintDialog() {
24: System.out.println("custom dialog paints....");
25: }
26: }
您可以使用Abstract Factory模式，將所有對話方塊所需要的產生的元件加以封裝，對話方塊依賴於Abstract Factory，實際上具體的Factory實現則分別產生對話方塊所需要的視感元件，下麵的 UML 類別圖展現這種概念。
現在如果要更換所有的視感元件，就隻要抽象掉具體的Factory就可以了，例如：
1: CustomDialog windowsDialog =
2: new CustomDialog(new WindowsWidgetFactory());
3: windowsDialog.showDialog();
4: CustomDialog macDialog =
5: new CustomDialog(new MacWidgetFactory());
6: macDialog.showDialog();
來將上麵的UML圖具體實現出來。
- CustomDialog.java
1: public class CustomDialog {
2: private IButton button;
3: private ITextField textField;
4:
5: public CustomDialog(IWidgetFactory widgetFactory) {
6: setWidgetFactory(widgetFactory);
7: }
8:
9: // 由於客戶端隻依賴於抽象的工廠，工廠如何實作並無關客戶端的事
10: // 要抽換工廠並不需要改動客戶端的程式
11: public void setWidgetFactory(IWidgetFactory widgetFactory) {
12: setButton(widgetFactory.getButton());
13: setTextField(widgetFactory.getTextField());
14:
15: }
16:
17: public void layoutAllComponents() {
18: // layout all components
19: }
20:
21: // 這邊也是依賴抽象，實際改變了元件實例
22: // 客戶端代碼也不用更改
23: public void setButton(IButton button) {
24: this.button = button;
25: }
26:
27: public void setTextField(ITextField textField) {
28: this.textField = textField;
29: }
30:
31: public void showDialog() {
32: this.paintDialog();
33: button.paintButton();
34: textField.paintTextField();
35: }
36:
37: public void paintDialog() {
38: System.out.println("custom dialog paints....");
39: }
40: }
- IButton.java
1: public interface IButton {
2: public void paintButton();
3: }
- ITextField.java
1: public interface ITextField {
2: public void paintTextField();
3: }
- IWidgetFactory.java
1: public interface IWidgetFactory {
2: public IButton getButton();
3: public ITextField getTextField();
4: }
- MacButton.java
1: public class MacButton implements IButton {
2: public void paintButton() {
3: System.out.println("Mac button paints....");
4: }
5: }
- WindowsButton.java
1: public class WindowsButton implements IButton {
2: public void paintButton() {
3: System.out.println("Windows button paints....");
4: }
5: }
- MacTextField.java
1: public class MacTextField implements ITextField {
2: public void paintTextField() {
3: System.out.println("Mac textField paints....");
4: }
5: }
- WindowsTextField.java
1: public class WindowsTextField implements ITextField {
2: public void paintTextField() {
3: System.out.println("Windows textField paints....");
4: }
5: }
- MacWidgetFactory.java
1: public class MacWidgetFactory implements IWidgetFactory {
2: public IButton getButton() {
3: return new MacButton();
4: }
5:
6: public ITextField getTextField() {
7: return new MacTextField();
8: }
9: }
- WindowsWidgetFactory.java
1: public class WindowsWidgetFactory
2: implements IWidgetFactory {
3: public IButton getButton() {
4: return new WindowsButton();
5: }
6:
7: public ITextField getTextField() {
8: return new WindowsTextField();
9: }
10: }
簡單的說，在Abstract Factory模式中將具體的Product封裝在具體Factory實現中，而客戶仍隻要麵對Factory與Product的抽象介麵，避免依賴於具 體的Factory與Product，由於Factory封裝了所必須的Product，所以要更換掉所有的元件，隻要簡單的抽換掉Factory就可以 了，不用修改客戶端的程式。
Edit bt Atlas
Time 2013/7/1 09:49
最後更新：2017-04-03 16:59:48