如何在不知道 json 文件中的属性的情况下，使用 ZD52387880E75EA281817A72 代码动态上传同一文件夹下的多个 json 文件到 MongoDB

Question

I am getting error:

exception in thread "main" org.bson.BsonInvalidOperationException: readStartDocument can only be called when CurrentBSONType is DOCUMENT, not when CurrentBSONType is ARRAY.

With the below code I am trying to insert only one json file. Could you please help me?

   public class hallo {

    public static void main( String args[] ) {

        // Creating a Mongo client
        MongoClient mongo = new MongoClient( "localhost" , 27017 );


        // Accessing the database
        MongoDatabase database = mongo.getDatabase("dumpJsonFiles");
        //System.out.println("Credentials ::"+ credential);

        //Creating a collection
        //database.createCollection("sampleCollection1");
        System.out.println("Collection created successfully");
        MongoCollection<Document> collection = database.getCollection("new_name");
        System.out.println("Collection myCollection selected successfully");
        Document document = new Document("title", "MongoDB")
                .append("description", "database")
                .append("likes", 100)
                .append("url", "http://www.tutorialspoint.com/mongodb/")
                .append("by", "tutorials point");

        //Inserting document into the collection
        collection.insertOne(document);
        System.out.println("Document inserted successfully");
        List<InsertOneModel<Document>> docs = new ArrayList<>();
        int count = 0;
        int batch = 100;
        try (BufferedReader br = new BufferedReader(new FileReader("sample.json"))) {
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println("line is "+line);
                docs.add(new InsertOneModel<>(Document.parse(line)));
                count++;
                if (count == batch) {
                    collection.bulkWrite(docs, new BulkWriteOptions().ordered(false));
                    docs.clear();
                    count = 0;
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        if (count > 0) {
            collection.bulkWrite(docs, new BulkWriteOptions().ordered(false));
        }
        //DBObject dbObject = (DBObject)JSON.parse("sample.json");

        System.out.println("Document inserted 2 successfully");

    }
}

---

The input JSON file sample contents (copied from comments):

{
   "Details":{
      "Name":"AC",
      "Rollno":"5978",
      "section":"",
      "Maths":"10",
      "Science":"20",
      "social":"20",
      "English":"30"
   }
}

Another json file is:

[
   {
      "Name":"Table",
      "Description":"Used",
      "Marks":[
         {
            "Social":"10",
            "Science":"20",
            "Maths":"30",
            "English":"40",
            "Hindi":"50",
            "Computers":[
               {
                  "Lab":"10",
                  "Theory":"20"
               }
            ]
         }
      ]
   }
]

Answer 1

I am getting error:

exception in thread "main" org.bson.BsonInvalidOperationException: readStartDocument can only be called when CurrentBSONType is DOCUMENT, not when CurrentBSONType is ARRAY.

With the below code I am trying to insert only one json file. Could you please help me?

   public class hallo {

    public static void main( String args[] ) {

        // Creating a Mongo client
        MongoClient mongo = new MongoClient( "localhost" , 27017 );


        // Accessing the database
        MongoDatabase database = mongo.getDatabase("dumpJsonFiles");
        //System.out.println("Credentials ::"+ credential);

        //Creating a collection
        //database.createCollection("sampleCollection1");
        System.out.println("Collection created successfully");
        MongoCollection<Document> collection = database.getCollection("new_name");
        System.out.println("Collection myCollection selected successfully");
        Document document = new Document("title", "MongoDB")
                .append("description", "database")
                .append("likes", 100)
                .append("url", "http://www.tutorialspoint.com/mongodb/")
                .append("by", "tutorials point");

        //Inserting document into the collection
        collection.insertOne(document);
        System.out.println("Document inserted successfully");
        List<InsertOneModel<Document>> docs = new ArrayList<>();
        int count = 0;
        int batch = 100;
        try (BufferedReader br = new BufferedReader(new FileReader("sample.json"))) {
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println("line is "+line);
                docs.add(new InsertOneModel<>(Document.parse(line)));
                count++;
                if (count == batch) {
                    collection.bulkWrite(docs, new BulkWriteOptions().ordered(false));
                    docs.clear();
                    count = 0;
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        if (count > 0) {
            collection.bulkWrite(docs, new BulkWriteOptions().ordered(false));
        }
        //DBObject dbObject = (DBObject)JSON.parse("sample.json");

        System.out.println("Document inserted 2 successfully");

    }
}

---

The input JSON file sample contents (copied from comments):

{
   "Details":{
      "Name":"AC",
      "Rollno":"5978",
      "section":"",
      "Maths":"10",
      "Science":"20",
      "social":"20",
      "English":"30"
   }
}

Another json file is:

[
   {
      "Name":"Table",
      "Description":"Used",
      "Marks":[
         {
            "Social":"10",
            "Science":"20",
            "Maths":"30",
            "English":"40",
            "Hindi":"50",
            "Computers":[
               {
                  "Lab":"10",
                  "Theory":"20"
               }
            ]
         }
      ]
   }
]