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java操作mongodb(分頁)

使用skip+limit的方式實現分頁。直接上程式碼(依賴的程式碼在上一篇部落格中):

/**
	 * 分頁查詢
	 * @param page
	 * @param pageSize
	 * @return
	 */
	public List<User> pageList(int page,int pageSize){
		DB myMongo = MongoManager.getDB("myMongo");
		DBCollection userCollection = myMongo.getCollection("user");
		
		DBCursor limit = userCollection.find().skip((page - 1) * 10).sort(new BasicDBObject()).limit(pageSize);		List<User> userList = new ArrayList<User>();
		while (limit.hasNext()) {
			User user = new User();
			user.parse(limit.next());
			userList.add(user);
		}
		return userList;
	}
List<User> list = userAction.pageList(1,10);
		for(User user : list){
			System.out.println(user);
		}
		System.out.println("=======================");
		list = userAction.pageList(2,10);
		for(User user : list){
			System.out.println(user);
		}

輸出如下:

id:2,name:manman,address:beijing
id:1,name:jinhui,address:beijing
id:3,name:3,address:3
id:4,name:4,address:4
id:5,name:5,address:5
id:6,name:6,address:6
id:7,name:7,address:7
id:8,name:8,address:8
id:9,name:9,address:9
id:10,name:10,address:10
=======================
id:11,name:11,address:11
id:12,name:12,address:12
id:13,name:13,address:13
id:13,name:13,address:13
id:13,name:13,address:13
id:13,name:13,address:13
id:13,name:13,address:13


 注意:

使用skip跳過少量的資料是很好的選擇,但是如果跳過大量的資料的時候,skip方法就會執行的很慢。所以我們要儘量的避免使用skip跳過大量的資料。後面我們會提到如何優化大資料量的分頁。