假设您要制作一个对话方块（Dialog）元件，您希望的是这个对话方块可以有不同的视感（Look-and- feel），最基本的想法是，藉由Setter将不同视感的元件设定给这个对话方块，例如：

• CustomDialog.java

public class CustomDialog {    private IButton button;    private ITextField textField;        public CustomDialog(IWidgetFactory widgetFactory) {        setWidgetFactory(widgetFactory);    }        // 由于客户端只依赖于抽象的工厂，工厂如何实作并无关客户端的事    // 要抽换工厂并不需要改动客户端的程式    public void setWidgetFactory(IWidgetFactory widgetFactory) {        setButton(widgetFactory.getButton());        setTextField(widgetFactory.getTextField());         }    public void layoutAllComponents() {        // layout all components    }        // 这边也是依赖抽象，实际改变了元件实例    // 客户端代码也不用更改    public void setButton(IButton button) {        this.button = button;        }        public void setTextField(ITextField textField) {        this.textField = textField;    }        public void showDialog() {        this.paintDialog();        button.paintButton();        textField.paintTextField();    }      public void paintDialog() {        System.out.println("custom dialog paints....");    }}

现在如果要更换所有的视感元件，就只要抽象掉具体的Factory就可以了，例如：

CustomDialog windowsDialog = 

来将上面的UML图具体实现出来。

• CustomDialog.java

public class CustomDialog {
    private IButton button; private ITextField textField; public CustomDialog(IWidgetFactory widgetFactory) {
    setWidgetFactory(widgetFactory); } // 由于客户端只依赖于抽象的工厂，工厂如何实作并无关客户端的事 // 要抽换工厂并不需要改动客户端的程式 public void setWidgetFactory(IWidgetFactory widgetFactory) {
    setButton(widgetFactory.getButton()); setTextField(widgetFactory.getTextField()); } public void layoutAllComponents() {
    // layout all components } // 这边也是依赖抽象，实际改变了元件实例 // 客户端代码也不用更改 public void setButton(IButton button) {
    this.button = button;    } public void setTextField(ITextField textField) {
    this.textField = textField; } public void showDialog() {
    this.paintDialog(); button.paintButton(); textField.paintTextField(); } public void paintDialog() {
    System.out.println("custom dialog paints...."); } }

• IButton.java

public interface IButton {
    public void paintButton(); }

• ITextField.java

public interface ITextField {
    public void paintTextField(); }

• IWidgetFactory.java

public interface IWidgetFactory {
    public IButton getButton(); public ITextField getTextField(); }

• MacButton.java

public class MacButton implements IButton {
    public void paintButton() {
    System.out.println("Mac button paints...."); } }

• WindowsButton.java

public class WindowsButton implements IButton {
    public void paintButton() {
    System.out.println("Windows button paints...."); } }

• MacTextField.java

public class MacTextField implements ITextField {
    public void paintTextField() {
    System.out.println("Mac textField paints...."); } }

• WindowsTextField.java

public class WindowsTextField implements ITextField {
    public void paintTextField() {
    System.out.println("Windows textField paints...."); } }

• MacWidgetFactory.java

public class MacWidgetFactory implements IWidgetFactory {
    public IButton getButton() {
    return new MacButton(); } public ITextField getTextField() {
    return new MacTextField(); } }

• WindowsWidgetFactory.java

public class WindowsWidgetFactory implements IWidgetFactory {
    public IButton getButton() {
    return new WindowsButton(); } public ITextField getTextField() {
    return new WindowsTextField(); } }

简单的说，在Abstract Factory模式中将具体的Product封装在具体Factory实现中，而客户仍只要面对Factory与Product的抽象介面，避免依赖于具 体的Factory与Product，由于Factory封装了所必须的Product，所以要更换掉所有的元件，只要简单的抽换掉Factory就可以 了，不用修改客户端的程式。