抽象工廠

以下設計模式被歸類為建立模式。

抽象工廠用於提供用於建立相關物件族的介面，而無需指定具體類，並且可用於隱藏特定於平臺的類。

interface Tool {
    void use();
}

interface ToolFactory {
    Tool create();
}

class GardenTool implements Tool {

    @Override
    public void use() {
         // Do something...
    }
}

class GardenToolFactory implements ToolFactory {

    @Override
    public Tool create() {
        // Maybe additional logic to setup...
        return new GardenTool();
    }
}

class FarmTool implements Tool {

    @Override
    public void use() {
        // Do something...
    }
}

class FarmToolFactory implements ToolFactory {

    @Override
    public Tool create() {
        // Maybe additional logic to setup...
        return new FarmTool();
    }
}

然後將使用某種型別的供應商/生產商，這些供應商/生產商將傳遞資訊，以便它能夠回饋正確型別的工廠實施：

public final class FactorySupplier {

    // The supported types it can give you...
    public enum Type {
        FARM, GARDEN
    };

    private FactorySupplier() throws IllegalAccessException {
        throw new IllegalAccessException("Cannot be instantiated");
    }

    public static ToolFactory getFactory(Type type) {

        ToolFactory factory = null;

        switch (type) {
        case FARM:
            factory = new FarmToolFactory();
            break;
        case GARDEN:
            factory = new GardenToolFactory();
            break;
        } // Could potentially add a default case to handle someone passing in null

        return factory;
    }
}