模板方法模式在一个方法中定义一个算法的骨架，而将一些步骤延迟到子类中。模版方法是的子类可以在不改变算法结构的情况下，重新定义算法中的某些步骤。

类图

（图片源于网络）

代码实现（Java）

// CaffeineBeverage.javapublic abstract class CaffeineBeverage {                                                        final void prepareRecipe() {        boilWater();        brew();        pourInCup();        addCondiments();    }                                                       abstract void brew();                                                        abstract void addCondiments();                                                       void boilWater() {        System.out.println("Boiling water");    }                                                        void pourInCup() {        System.out.println("Pouring into cup");    }}

// CaffeineBeverageWithHook.javapublic abstract class CaffeineBeverageWithHook {                                                    void prepareRecipe() {        boilWater();        brew();        pourInCup();        if (customerWantsCondiments()) {            addCondiments();        }    }                                                    abstract void brew();                                                    abstract void addCondiments();                                                    void boilWater() {        System.out.println("Boiling water");    }                                                    void pourInCup() {        System.out.println("Pouring into cup");    }                                                    boolean customerWantsCondiments() {        return true;    }}

// Coffee.javapublic class Coffee extends CaffeineBeverage {    public void brew() {        System.out.println("Dripping Coffee through filter");    }    public void addCondiments() {        System.out.println("Adding Sugar and Milk");    }}

// CoffeeWithHook.javapublic class CoffeeWithHook extends CaffeineBeverageWithHook {                                              public void brew() {        System.out.println("Dripping Coffee through filter");    }                                              public void addCondiments() {        System.out.println("Adding Sugar and Milk");    }                                              public boolean customerWantsCondiments() {        String answer = getUserInput();        if (answer.toLowerCase().startsWith("y")) {            return true;        } else {            return false;        }    }                                              private String getUserInput() {        String answer = null;        System.out.print("Would you like milk and sugar with your coffee (y/n)? ");        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));        try {            answer = in.readLine();        } catch (IOException ioe) {            System.err.println("IO error trying to read your answer");        }        if (answer == null) {            return "no";        }        return answer;    }}

// Tea.javapublic class Tea extends CaffeineBeverage {    public void brew() {        System.out.println("Steeping the tea");    }    public void addCondiments() {        System.out.println("Adding Lemon");    }}

// TeaWithHook.javapublic class TeaWithHook extends CaffeineBeverageWithHook {                           public void brew() {        System.out.println("Steeping the tea");    }                           public void addCondiments() {        System.out.println("Adding Lemon");    }                           public boolean customerWantsCondiments() {        String answer = getUserInput();        if (answer.toLowerCase().startsWith("y")) {            return true;        } else {            return false;        }    }                           private String getUserInput() {        // get the user's response        String answer = null;        System.out.print("Would you like lemon with your tea (y/n)? ");        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));        try {            answer = in.readLine();        } catch (IOException ioe) {            System.err.println("IO error trying to read your answer");        }        if (answer == null) {            return "no";        }        return answer;    }}

测试代码

// BeverageTestDrive.javapublic class BeverageTestDrive {    public static void main(String[] args) {                                     Tea tea = new Tea();        Coffee coffee = new Coffee();                                     System.out.println("\nMaking tea...");        tea.prepareRecipe();                                     System.out.println("\nMaking coffee...");        coffee.prepareRecipe();                                     TeaWithHook teaHook = new TeaWithHook();        CoffeeWithHook coffeeHook = new CoffeeWithHook();                                     System.out.println("\nMaking tea...");        teaHook.prepareRecipe();                                     System.out.println("\nMaking coffee...");        coffeeHook.prepareRecipe();    }}

运行效果