epgloader.java

基于JMS架构的电子节目单EPG下载子模块

package com.temobi.epg.publisher.bo;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import com.temobi.epg.publisher.EpgPublisherConstant;
import common.context.SystemContext;
import common.exception.BakupException;
import common.exception.RestoreException;
import common.log.proxy.JLogger;
import common.log.proxy.LoggerFactory;
import common.util.FileTool;
import common.util.HttpLoader;

/**
 * EPG文件下载
 * 
 * @author lixu
 * 
 */
public class EpgLoader {
	private static JLogger log = LoggerFactory.getLogger(EpgLoader.class);

	private List<String> loadUrls;

	private String epgRootDir;

	public EpgLoader(List<String> loadUrls) {
		this.loadUrls = loadUrls;
		this.epgRootDir = SystemContext.getInstance().getValue(
				EpgPublisherConstant.EPG_DIR);
	}

	/**
	 * 下载
	 * 
	 * @throws IOException
	 */
	public void load() throws IOException, BakupException {
		// 解析EPG目录结构
		List<String> dirs = EpgDirTool.parseEpgDirFromUrl(loadUrls);
		// 如果EPG目录不存在,创建EPG目录结构
		EpgDirTool.createEpgDirStructor(dirs, this.epgRootDir);
		// 获取第一层目录
		List<String> levelOneDirs = EpgDirTool.getLevelOneEpgDir(dirs);
		List<File> levelOneFiles = this.formatToFile(levelOneDirs);
		// 创建临时用的EPG目录结构
		List<File> tempFiles = EpgDirTool.createTempEpgDirStructor(dirs,
				this.epgRootDir);

		// 把远程的EPG文件下载到临时目录里
		for (String url : loadUrls) {
			HttpLoader httpLoader = new HttpLoader();
			File file = EpgDirTool.generateTempEpgFile(url, this.epgRootDir);
			httpLoader.load(url, file);
		}

		// 把当前的目录进行重命名备份
		List<File> bakFiles = this.bakupEpgDir(levelOneFiles);
		// 把临时文件命名为正式文件
		File tempFile;
		File file;
		try {
			for (int i = 0; i < tempFiles.size(); i++) {
				tempFile = tempFiles.get(i);
				file = levelOneFiles.get(i);
				if (!tempFile.renameTo(file))
					throw new IOException("Rename file["
							+ tempFile.getAbsolutePath() + "] to file["
							+ file.getAbsolutePath() + "] occur error!");
			}
			log.info("load epg success!");
		} catch (IOException e) {
			log.warn(e.getMessage());
			// 还原
			this.restoreEpgDir(levelOneFiles, bakFiles);
		}
		EpgDirTool.deleteMoreBakupDir(new File(this.epgRootDir));
	}

	/**
	 * 把用字符串表示的文件格式为File对象
	 * 
	 * @param levelOneDirs
	 * @return
	 */
	private List<File> formatToFile(List<String> levelOneDirs) {
		List<File> files = new ArrayList<File>(levelOneDirs.size());

		for (String src : levelOneDirs) {
			File f = new File(this.epgRootDir + src);
			files.add(f);
		}
		return files;
	}

	/**
	 * 对EPG目录结构进行重命名备份
	 * 
	 * @param dirs
	 * @return
	 * @throws BakupException
	 */
	private List<File> bakupEpgDir(List<File> dirs) throws BakupException {
		List<File> bakFiles = new ArrayList<File>(dirs.size());
		Date now = new Date();
		File bakFile;
		for (File f : dirs) {
			bakFile = EpgDirTool.generateBakupFile(f, now);
			bakFiles.add(bakFile);
			FileTool.bakup(f, bakFile);
		}
		return bakFiles;
	}

	/**
	 * 还原EPG备份的目录
	 * 
	 * @param dirs
	 * @param bakDirs
	 * @throws BakupException
	 */
	private void restoreEpgDir(List<File> dirs, List<File> bakDirs)
			throws BakupException {

		for (int i = 0; i < dirs.size(); i++) {
			try {
				FileTool.restore(dirs.get(i), bakDirs.get(i));
			} catch (RestoreException e) {
				log.error(e.getMessage(), e);
			}
		}
	}
}