设计模式之抽象工厂模式

抽象工厂模式

提供一个创建一系列相关或者相互依赖的对象的接口，而无需指定他们具体的类。

User

package com.hml.factory.abstr;

public class User {

}

Department

package com.hml.factory.abstr;

public class Department {

}

IUser

package com.hml.factory.abstr;

public interface IUser {
    
    public void insert(User user);
    
    public User getUser(int id);
}

IDepartment

package com.hml.factory.abstr;

public interface IDpartment {
    
    public void insert(Department department);
    
    public Department getDepartment(int id);
}

SqlserverUser

package com.hml.factory.abstr;

public class SqlserverUser implements IUser {

    public void insert(User user) {
        System.out.println("SqlserverUser");        
    }

    public User getUser(int id) {
        System.out.println("SqlserverUser");
        return null;
    }

}

SqlserverDepartment

package com.hml.factory.abstr;

public class SqlserverDepartment implements IDpartment {

    public void insert(Department department) {
        System.out.println("SqlserverDepartment");
    }

    public Department getDepartment(int id) {
        System.out.println("SqlserverDepartment");
        return null;
    }

}

OracleUser

package com.hml.factory.abstr;

public class OracleUser implements IUser {

    public void insert(User user) {
        System.out.println("SqlserverUser");        
    }

    public User getUser(int id) {
        System.out.println("SqlserverUser");
        return null;
    }

}

OracleDepartment

package com.hml.factory.abstr;

public class OracleDepartment implements IDpartment {

    public void insert(Department department) {
        System.out.println("OracleDepartment");
    }

    public Department getDepartment(int id) {
        System.out.println("OracleDepartment");
        return null;
    }

}

IFactory

package com.hml.factory.abstr;

public interface IFactory {

    public IUser createUser();
    
    public IDpartment createDepartment();
}

SqlserverFactory

package com.hml.factory.abstr;

public class SqlserverFactory implements IFactory {

    public IUser createUser() {
        return new SqlserverUser();
    }

    public IDpartment createDepartment() {
        return new SqlserverDepartment();
    }

}

 OracleFatory

package com.hml.factory.abstr;

public class OracleFactory implements IFactory {

    public IUser createUser() {
        return new OracleUser();
    }

    public IDpartment createDepartment() {
        return new OracleDepartment();
    }

}

Test

package com.hml.factory.abstr;

public class Test {

    public static void main(String[] args) {
        
        IFactory factory = new SqlserverFactory(); //  new OracleFactory();
        
        User user = new User();
        
        factory.createUser().insert(user);
        
    }
}

类图

抽象工厂的优点：1、便于交换产品系列，由于具体工厂类，在一个应用中只需在初始化的时候出现一次，这就使得改变一个应用的具体工厂变得非常容易，只需要改变具体工厂即可使用不同的产品配置。2、他让具体创建实例的过程与客户分离，客户端是通过他们的抽象接口操作实例，产品的具体类名也被工厂的实现分离，不会出现在客户代码中。

该实例可通过配置文件然后再通过反射进行更近一步的封装，这样客户端代码就不用与具体的工厂类交互。