Code Fragment-使用枚举策略模式表示状态

代码如下：

package com.jue.test;

public enum DownloadStatus {

	STATUS_DOWNLOAD_ING("下载中", "下载时的icon", "点击暂停"),
	STATUS_DOWNLOAD_DONE("下载已经完成", "完成的icon", "点击安装"),
	STATUS_DOWNLOAD_NEW("新建任务","新的下载任务icon", "点击下载"),
	STATUS_DOWNLOAD_PAUSE("暂停下载", "暂停的icon","点击继续下载");

	String title;
	String iconDes;
	String action;

	private DownloadStatus(String title, String iconDes, String action) {
		this.title = title;
		this.iconDes = iconDes;
		this.action = action;
	}

}

测试调用如下：

package com.jue.test;

public class Video {

	public DownloadStatus status = DownloadStatus.STATUS_DOWNLOAD_NEW;

	public static void main(String[] args) {
		Video video = new Video();
		video.status = DownloadStatus.STATUS_DOWNLOAD_ING;
		display(video.status.title, video.status.iconDes, video.status.action);
	}

	public static void display(String status, String iconDes, String action) {
		System.out.println("现在是  [" + status + "]  状态，显示的是[" + iconDes
				+ "]，点击会触发  [" + action+"]");
	}
}

优点如下：

1. 枚举的状态值本身携带了状态的一些信息，保证了数据的一致性，摒弃了大量的if else或switch case判断。