mongodb的GridFS使用

import java.io.File;
import java.net.UnknownHostException;

import com.mongodb.DB;
import com.mongodb.Mongo;
import com.mongodb.MongoException;
import com.mongodb.gridfs.GridFS;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSInputFile;


public class Show {

	public static void main(String[] args) throws UnknownHostException,
			MongoException {

		Mongo host = new Mongo("localhost");
		DB db = host.getDB("demo");
		db.addUser("admin", "admin".toCharArray());
		boolean auth = db.authenticate("admin", "admin".toCharArray());
		if (auth) {
			String file, newFilename, bucket, saveTo;
			bucket = "fs";
			newFilename = "image1";
			file = "e:/2.jpg";// 本地文件路径
			saveTo = "e:/images/2.jpg";

			db.requestStart();
			try {
				// ----------文件保存
				File files = new File(file);
				GridFS gfs = new GridFS(db, bucket);
				GridFSInputFile gfsInput = gfs.createFile(files);
				gfsInput.setFilename(newFilename);
				gfsInput.setContentType("");
				gfsInput.save();
				db.requestDone();

				// 文件读取，并保存成新的文件名saveTo
				GridFSDBFile dbFile = gfs.findOne(newFilename);
				if (dbFile != null)
					System.out.println("file size:" + dbFile.writeTo(saveTo));

				// 删除数据库中的文件
				//gfs.remove(newFilename);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

		}

	}

}