创建型模式之工厂方法模式（日志记录器）

末蓝、 2022-08-09 18:56 145阅读 0赞

题目：某系统日志记录器要求支持多种日志记录方式，如文件日志记录(FileLog)、数据库日志记录(DatabaseLog)等，且用户可以根据要求动态选择日志记录方式，现使用工厂模式设计该系统。

类图

![20151104153836571][]

package cn.factory2;
    
    public class Client {
    	public static void main(String[] args) {
    		try {
    			Log log;
    			//LogFactory factory1;
    			LogFactory factory2;
    			//factory1 = new DatabaseLogFactory();
    			factory2 = new FileLogFactory();
    			//factory = (LogFactory)XMLUtil.getBean();
    			log = factory2.createLog();
    			log.writeLog();
    		} catch(Exception e) {
    			System.out.println(e.getMessage());
    		}
    	}
    }

package cn.factory2;
    
    public class DatabaseFile implements Log{
    	public void writeLog() {
    		System.out.println("数据库日志写入中。。。");
    	}
    }

package cn.factory2;
    
    public class DatabaseLogFactory implements LogFactory{
    	public Log createLog() {
    		System.out.println("数据库日志工厂生产数据库日志。");
    		return new DatabaseFile();
    	}
    }

package cn.factory2;
    
    public class FileLog implements Log{
    	public void writeLog() {
    		System.out.println("文件日志写入中。。。");
    	}
    }

package cn.factory2;
    
    public class FileLogFactory implements LogFactory{
    	public Log createLog() {
    		System.out.println("文件日志工厂生产文件日志。");
    		return new FileLog();
    	}
    }

package cn.factory2;
    
    public interface Log {
    	public void writeLog();
    }

package cn.factory2;
    
    public interface LogFactory {
    	public Log createLog();
    }

运行效果图

![20151104154014938][]

[20151104153836571]: /images/20220731/b1591f06376b47b9a0b58c2448256ea7.png
[20151104154014938]: /images/20220731/468bbd2a48cc41e99caefb9f33b6ad89.png