MongoDB java 更新时间戳Timestamp

参考：https://blog.csdn.net/u013066244/article/details/80004153

public static void main(String[] args) {
    final MongoCollection<Document> useropRecord;
    //连接数据库 start
    MongoCredential credential = MongoCredential.createCredential("user", "user", "user.gogoal.com".toCharArray());
    ServerAddress serverAddress;
    serverAddress = new ServerAddress("192.168.11.22", 22);
    List<ServerAddress> addrs = new ArrayList<ServerAddress>();
    addrs.add(serverAddress);
    List<MongoCredential> credentials = new ArrayList<MongoCredential>();
    credentials.add(credential);
    @SuppressWarnings("resource")
    MongoClient mongoClient = new MongoClient(addrs, credentials);
    System.out.println("Connect to database successfully");
    //连接数据库 end

    MongoDatabase database = mongoClient.getDatabase("user");

    useropRecord = database.getCollection("userop_record");//埋点表

    Document match = new Document();
    match.append("_tm", null);

    Date stringToDate = DateUtil.stringToDate("2018-04-01", "yyyy-MM-dd");
    match.append("date", new Document("$gte", stringToDate));
    useropRecord.find(match).forEach(new Block<Document>() {
        int aa=3000;
        @Override
        public void apply(Document doc) {
            Document project = new Document();
            project.append("$set", new Document("_tm", new BSONTimestamp((int)(System.currentTimeMillis() / 1000), aa++)));
            useropRecord.updateMany(new BasicDBObject("_id", doc.get("_id")), project);
            if(aa >= 4000){
                aa = 3000;
            }
          }
        }
    );
}

注意，使用BSONTimestamp或者BsonTimestamp，需要在系统时间上除以1000，因为系统给的时间是毫秒。