11-抽象工厂模式

概念

抽象工厂模式，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

举例

项目中需要将数据库从SqlServer换成Access,User表和Department表的插入和获取都需要重写

package com.niao.abstractFactory;

public interface IUser {
    void insert(User user);

    User get(String id);
}

package com.niao.abstractFactory;

public class SqlServerUser implements IUser{
    @Override
    public void insert(User user) {
        System.out.println("在sqlServer中插入user数据");
    }

    @Override
    public User get(String id) {
        System.out.println("在sqlServer中获取user数据");
        return null;
    }
}

package com.niao.abstractFactory;

public class AccessUser implements IUser{
    @Override
    public void insert(User user) {
        System.out.println("在Access中插入user数据");
    }

    @Override
    public User get(String id) {
        System.out.println("在Access中获取user数据");
        return null;
    }
}

package com.niao.abstractFactory;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
    private String id;
    private String name;
    private String password;
}

package com.niao.abstractFactory;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Department {
    private String id;
    private String name;
    private int peopleNum;
}

package com.niao.abstractFactory;

public interface IDepartment {
    void insert(Department department);

    Department get(String id);
}

package com.niao.abstractFactory;

public class AccessDepartment implements IDepartment{
    @Override
    public void insert(Department department) {
        System.out.println("在Access中插入department数据");
    }

    @Override
    public Department get(String id) {
        System.out.println("在Access中获取department数据");
        return null;
    }
}

package com.niao.abstractFactory;

public class SqlServerDepartment implements IDepartment{
    @Override
    public void insert(Department department) {
        System.out.println("在SqlServer中插入department数据");
    }

    @Override
    public Department get(String id) {
        System.out.println("在SqlServer中获取department数据");
        return null;
    }
}

package com.niao.abstractFactory;

public interface IFactory {
    IUser createUser();

    IDepartment createDepartment();
}

package com.niao.abstractFactory;

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

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

package com.niao.abstractFactory;

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

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

package com.niao.abstractFactory;

import com.sun.org.slf4j.internal.Logger;
import com.sun.org.slf4j.internal.LoggerFactory;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class PropertyUtil {
    private static Properties props;
    static{
        loadProps();
    }

    synchronized static private void loadProps(){
        System.out.println("开始加载properties文件内容.......");
        props = new Properties();
        InputStream in = null;
        try {
//　　　　　　　<!--第一种，通过类加载器进行获取properties文件流-->
                    in = PropertyUtil.class.getClassLoader().getResourceAsStream("application.properties");
//　　　　　　 <!--第二种，通过类进行获取properties文件流-->
                    //in = PropertyUtil.class.getResourceAsStream("/jdbc.properties");
                    props.load(in);
        } catch (FileNotFoundException e) {
            System.out.println("jdbc.properties文件未找到");
        } catch (IOException e) {
            System.out.println("出现IOException");
        } finally {
            try {
                if(null != in) {
                    in.close();
                }
            } catch (IOException e) {
                System.out.println("jdbc.properties文件流关闭出现异常");
            }
        }
        System.out.println("加载properties文件内容完成...........");
        System.out.println("properties文件内容：" + props);
    }

    public static String getProperty(String key){
        if(null == props) {
            loadProps();
        }
        return props.getProperty(key);
    }

    public static String getProperty(String key, String defaultValue) {
        if(null == props) {
            loadProps();
        }
        return props.getProperty(key, defaultValue);
    }
}

package com.niao.abstractFactory;

public class Client {
    public static void main(String[] args) {
        // 抽象工厂模式实现
//        IFactory factory = new SqlServerFactory();
//        IFactory factory = new AccessFactory();
//        IDepartment department = factory.createDepartment();

        // 简单工厂模式实现
        IDepartment department = DataAccess.createDepartment();


        Department department1 = new Department("1", "教育部", 50);
        department.insert(department1);

    }
}

package com.niao.abstractFactory;


public class DataAccess {

//    private static final String DB = "SqlServer";
    private static final String DB = PropertyUtil.getProperty("database.type");

    public static IUser createUser(){
        IUser result = null;
        switch (DB){
            case "SqlServer":
                result = new SqlServerUser();
                break;
            case "Access":
                result = new AccessUser();
                break;
        }
        return result;
    }

    public static IDepartment createDepartment(){
        IDepartment result = null;
        switch (DB){
            case "SqlServer":
                result = new SqlServerDepartment();
                break;
            case "Access":
                result = new AccessDepartment();
                break;
        }
        return result;
    }
}

database.type=Access

待实现

使用反射代替switch还未实现，遗留