java 两个mongo库数据迁移

    public static void main(String[] args) {
        String collectionname = "test";

        // MongoDB URI
        String uri = "mongodb://用户名:密码@ip:端口/mydatabase?authSource=mongo";

        // Connect to the database using the provided URI
        MongoClient sourceClient = new MongoClient(new MongoClientURI(uri));

        // 连接源数据库
        MongoDatabase sourceDb = sourceClient.getDatabase("mongo");
        MongoCollection<Document> collection = sourceDb.getCollection(collectionname);

        //设置查询条件
        BasicDBObject query = new BasicDBObject();
       // query.put("_id", new BasicDBObject("$in", Arrays.asList(1, 3, 5)));

        //执行查询
        FindIterable<Document> documents = collection.find(query);
        String taruri = "mongodb://用户名:密码@ip:端口/mydatabase?authSource=mongo";
        MongoClient targetClient = new MongoClient(new MongoClientURI(taruri));

        // 连接目标数据库
        MongoCollection<Document> targetCollection = targetClient.getDatabase("mongo_bpc").getCollection(collectionname);

        MongoCursor<Document> iterator = documents.iterator();
        while (iterator.hasNext()) {
            Document document = iterator.next();
            targetCollection.insertOne(document);
        }

        log.info("完成！");

        // 关闭连接
        sourceClient.close();
        targetClient.close();
    }

　　两个mongo数据迁移

1.不需要用户名密码时

　　MongoClient sourceClient = new MongoClient("ip", 端口)

　　MongoDatabase sourceDb = sourceClient.getDatabase("mongo");

//获取到要查询的集合（collection）

　　MongoCollection<Document> collection = sourceDb.getCollection(collectionname);

2.需要用户名密码

// MongoDB URI
　　String uri = "mongodb://用户名:密码@ip:端口/mydatabasse?authSource=mongo";

// 首先创建了一个MongoClient对象，通过提供的MongoDB URI进行连接
　　MongoClient sourceClient = new MongoClient(new MongoClientURI(uri));

　　MongoDatabase sourceDb = sourceClient.getDatabase("mongo");

//获取到要查询的集合（collection）

　　MongoCollection<Document> collection = sourceDb.getCollection(collectionname);