使用Java將數據插入mongodb

Question

我正在嘗試使用Java將數據插入MongoDB，但是在嘗試編譯代碼時出現錯誤。 我不知道是什么原因引起的錯誤。 我想添加一個新書條目。

 error message: required: String,Object found: List<Document> reason: actual and formal argument lists differ in length UseMongoDB.java:61: error: method put in class Document cannot be applied to given types; book.put(publishers); 

 private MongoCollection<Document> books = db.getCollection("books"); void insertanewbook() { Document book = new Document(); book.put("title", "test"); book.put("category","test"); book.put("price",12.3); List<Document> authors = new ArrayList<Document>(); Document author = new Document(); author.put("first_name","jonn"); author.put("last_name","james"); author.put("country","t"); author.put("website","www.test.com"); authors.add(author); book.put(authors); List<Document> publishers = new ArrayList<Document>(); Document publisher = new Document(); publisher.put("publish_date",new Date()); publisher.put("name","test"); publisher.put("country","test"); publisher.put("website","www.test.com"); publishers.add(publisher); book.put(publishers); books.insertOne(book); } 

Answer 1

從您發布的錯誤消息中...

reason: actual and formal argument lists differ in length

換句話說，方法put需要兩個參數，而您只提供了一個。 在您發布的代碼中，您缺少對方法put()的調用中的鍵 。 只需添加相關密鑰，例如

book.put("publishers", publishers);