将JSON解析为MONGODB文档

Question

I am new to JAVA and MONGODB and have been learning both to try and understand if these technologies would meet my requirements for a product.

I am currently stuck in a point where I am not able to insert documents(records) from JAVA into my MONGODB collection.

I am using the new MONGODB version 3.0 .

Code so far

MongoCollection<Document> coll = db.getCollection("Collection");
String json = "{'class':'Class10', 'student':{'name':'Alpha', 'sex':'Female'}, {'name':'Bravo', 'sex':'Male'}}";

I have found code to convert this to a DBObject type.

DBObject dbObject = (DBObject)JSON.parse(json);

But I guess the new version of MONGODB does not have the insert method but instead has the insertOne method .

coll.insertOne() requires that the input be in the Document format and does not accept the DBObject format.

coll.insertOne((Document) dbObject);

gives the error

com.mongodb.BasicDBObject cannot be cast to org.bson.Document

Can someone help me with the right type casting and give me a link where I could find and learn the same?

Regards.

Answer 1

使用在Document类中定义的静态解析（String json）方法。

Answer 2

• The problem is that you are using an older version(BasicDBObject) that is not compatible with version 3.0.

• But there is a way for 2.0 users to use BasicDBObject.An overload of the getCollection method allows clients to specify a different class for representing BSON documents.

The following code must work for you.

MongoCollection<BasicDBObject> coll = db.getCollection("Collection", BasicDBObject.class);

coll.insertOne(dbObject);

Answer 3

I used google gson for convert pojo to json, and this is work perfect.

private final MongoCollection<Document> collection;

//my save
    String json = gson.toJson(data);//data is User DTO, just pojo!
    BasicDBObject document = (BasicDBObject) JSON.parse(json);
    collection.insertOne(new Document(document));

Java mongodb driver version is 3.4.2