没有上下文类 Java 的策略模式

以下是使用没有上下文类的策略模式的简单示例。实现接口有两种实现策略，以不同的方式解决同一问题。通过指定所需策略，EnglishTranslation 类的用户可以调用 translate 方法并选择他们想要用于翻译的策略。

// The strategy interface
public interface TranslationStrategy {
    String translate(String phrase);
}

// American strategy implementation 
public class AmericanTranslationStrategy implements TranslationStrategy {

    @Override
    public String translate(String phrase) {
        return phrase + ", bro";
    }
}

// Australian strategy implementation     
public class AustralianTranslationStrategy implements TranslationStrategy {

    @Override
    public String translate(String phrase) {
        return phrase + ", mate";
    }
}

// The main class which exposes a translate method
public class EnglishTranslation {

    //  translate a phrase using a given strategy
    public static String translate(String phrase, TranslationStrategy strategy) {
        return strategy.translate(phrase);
    }

    // example usage
    public static void main(String[] args) {

        // translate a phrase using the AustralianTranslationStrategy class
        String aussieHello = translate("Hello", new AustralianTranslationStrategy());
        // Hello, mate

        // translate a phrase using the AmericanTranslationStrategy class    
        String usaHello = translate("Hello", new AmericanTranslationStrategy());
        // Hello, bro
    }
}