抽象工厂模式

定义：抽象工厂模式和工厂模式非常像，从定义出发，提供一个创建一系列相关或相互依赖对象的接口，而无需指定他们具体的类。（就像下面的实例一样，只有一个user类的时候其实就是工厂模式，但如果增加了department的时候，也就是多个产品，那么这就是抽象工厂模式）。

实体类：

public class User {
}

public class Department {
}

抽象产品类

public interface IUser {
    void Insert(User user);

    User getUser(int id);
}

public interface IDepartment {
    void Insert(Department department);

    Department getDepartment(int id);
}

抽象产品类的实现

public class SqlserverUser implements IUser {
    @Override
    public void Insert(User user) {
        System.out.println("在SQL server中给User插入一个数据");
    }

    @Override
    public User getUser(int id) {
        System.out.println("在SQL server中的user得到一条数据");
        return null;
    }
}

public class SqlserverDepartment implements IDepartment {
    @Override
    public void Insert(Department department) {
        System.out.println("在SQL server中给Department插入一个数据");
    }

    @Override
    public Department getDepartment(int id) {
        System.out.println("在SQL server中的Department得到一条数据");
        return null;
    }
}

public class AccessUser implements IUser {
    @Override
    public void Insert(User user) {
        System.out.println("在Access中的User插入一个数据");
    }

    @Override
    public User getUser(int id) {
        System.out.println("在Access中User得到一条数据");
        return null;
    }
}

public class AccessDepartment implements IDepartment {
    @Override
    public void Insert(Department department) {
        System.out.println("在Access中的Department插入一个数据");
    }

    @Override
    public Department getDepartment(int id) {
        System.out.println("在Access中Department得到一条数据");
        return null;
    }
}

抽象工厂类

public interface IFactory {
    IUser createUser();

    IDepartment createDepartment();
}

抽象工厂类的实现

public class SqlServerFactory implements IFactory {
    @Override
    public IUser createUser() {
        return new SqlserverUser();
    }

    @Override
    public IDepartment createDepartment() {
        return new AccessDepartment();
    }
}

public class AccessFactory implements IFactory {
    @Override
    public IUser createUser() {
        return new AccessUser();
    }

    @Override
    public IDepartment createDepartment() {
        return new AccessDepartment();
    }
}

Main：

public class Main {
    public static void main(String[] args) {
        User user = new User();
        Department department = new Department();

        IFactory factory = new SqlServerFactory();//IFactory factory = new AccessFactory()
        IUser iUser = factory.createUser();

        //然后可以进行数据的操作
    }
}