backupimpl.java

一个信息采集系统...对刚接触JSP和ＪＡＶＡ的人来说还有用

package com.briup.inf.impl;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.RandomAccessFile;
import java.util.Collection;
import java.util.Properties;

import com.briup.exception.BackupException;
import com.briup.inf.Backup;
import com.briup.inf.Config;
import com.briup.inf.Gather;

/**
 * class BackupImpl
 * 
 * @author Jimmy Zhou
 * @Date 2008-2-4 下午11:24:34
 */
public class BackupImpl implements Backup {
	private String bak_file_path;

	public BackupImpl(Properties pro) {
		bak_file_path = pro.getProperty("bak_file_path");
		createFile();
	}

	/**
	 * 清除备份文件内容
	 */
	public void clear() throws BackupException {

		try {
			RandomAccessFile raf = new RandomAccessFile(bak_file_path, "rw");
			raf.setLength(0);
			raf.close();
		} catch (Exception e) {
			e.printStackTrace();
			throw new BackupException(e);
		}

	}

	/**
	 * 导入备份数据文件内容，返回一个collection
	 */
	public Collection load() throws BackupException {
		Collection c = null;
		ObjectInputStream ois = null;
		File file = new File(bak_file_path);
		if (file.length() < 1) {
			clear();
		}
		if (file.length() > 1) {
			try {
				FileInputStream fis = new FileInputStream(file);
				ois = new ObjectInputStream(fis);
				Object obj = ois.readObject();
				if (obj != null) {
					c = (Collection) obj;
				}
			} catch (Exception e) {
				e.printStackTrace();
				throw new BackupException(e);
			} finally {
				if (ois != null) {
					try {
						ois.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
		}
		return c;
	}

	/**
	 * 当网络出现异常或想数据库插入记录时出现异常，将所有数据记录备份存储到备份文件中。
	 */
	public void store(Collection c) throws BackupException {
		File file = new File(bak_file_path);
		ObjectOutputStream oos = null;
		try {
			FileOutputStream fos = new FileOutputStream(file);
			oos = new ObjectOutputStream(fos);
			oos.writeObject(c);
			oos.flush();
		} catch (Exception e) {
			e.printStackTrace();
			throw new BackupException(e);
		} finally {
			try {
				if (oos != null) {
					oos.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	public void createFile() {
		File file = new File(bak_file_path);
		if (!file.exists()) {
			try {
				file.createNewFile();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}

	}

	public static void main(String[] agrs) {
		Properties pro = new Properties();
		pro.setProperty("config_file_path", "src/com/briup/config.xml");
		Config config = ConfigImpl.newInstance(pro);
		try {
			Backup bu = config.getBackup();
			Gather gather = config.getGather();
			Collection c1 = gather.doGather();
			System.out.println(c1.size());
			bu.store(c1);
			c1 = bu.load();
			System.out.println(c1.size());
			bu.clear();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}