mongoDB-java

从mongodb数据库中获取数据并存入对应的文件中

public static void main(String[] args) throws IOException {
		
		try {
			Mongo mongo = new Mongo("IP", 27017);
			DB db = mongo.getDB("databaseNAME");
			//用户认证
			boolean authenticate = db.authenticate("testadmin", "pptestadmin".toCharArray());
			String line = null ;
			if (authenticate) {
				DBCollection dbCollection = db.getCollection("collectionNAME");
				//查询条件
				DBCursor find = dbCollection.find(new BasicDBObject("d", "01"));
				while(find.hasNext()){
					DBObject next = find.next();
					line = next.toString();
//					System.out.println(next.toString());
					writeToFile(line);
				}
			}
			System.out.println("程序结束，over");
		} catch (UnknownHostException | MongoException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
	public static void writeToFile(String str) throws IOException{
		File file = new File("fileName");
		if (! file.exists()) {
			try {
				file.createNewFile();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		FileOutputStream fileOutputStream = null;
		try {
			
			//设置为true，防止后一条数据覆盖前一条数据
			fileOutputStream = new FileOutputStream(file, true);
			OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);
			BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);
			bufferedWriter.write(str);
			bufferedWriter.newLine();
			bufferedWriter.flush();
			bufferedWriter.close();
			outputStreamWriter.close();
			fileOutputStream.close();
//			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}