如何存储到MongoDB数据库中并使用Java从同一MongoDB数据库读取/加载？

Question

如何存储到MongoDB数据库中并使用Java从MongoDB数据库中读取

我写了这段代码，其中创建了数据库并存储了详细信息，但我似乎无法正确读取文件。它可以工作，但没有加载数据

private void saveandloadData(String[] trainSeats, String[] customerName, String[] traincustomerSeats, String userInput) {
        MongoClient dbb = new MongoClient("localhost", 27017);
        DB dbs = dbb.getDB("TrainCustomerandSeats");

        DBCollection coll1 = dbs.getCollection("CW1");
        DBCollection coll2 = dbs.getCollection("CW2");
        DBCollection coll3 = dbs.getCollection("CW3");

        if (userInput == "S" || userInput == "s"){
            storeData(trainSeats, customerName, traincustomerSeats, coll1, coll2, coll3);
        }else{
            loadData(trainSeats, customerName, traincustomerSeats, coll1, coll2, coll3);
        }
        optionEnter(trainSeats, customerName, traincustomerSeats);
    }

以下是我将数据存储到数据库中的部分：

private void storeData(String[] trainSeats, String[] customerName, String[] traincustomerSeats, DBCollection coll1, DBCollection coll2, DBCollection coll3) {

        BasicDBObject oneDoc = new BasicDBObject();
        for (int k = 1; k < trainSeats.length; k++){
            oneDoc.append(String.valueOf(k), trainSeats[k]);
        }
        coll1.insert(oneDoc);

        BasicDBObject twoDoc = new BasicDBObject();
        for(int k = 1; k < customerName.length; k++){
            twoDoc.append(String.valueOf(k), customerName[k]);
        }
        coll2.insert(twoDoc);

        BasicDBObject threeDoc = new BasicDBObject();
        for(int k = 1; k < traincustomerSeats.length; k++){
            threeDoc.append(String.valueOf(k), traincustomerSeats[k]);
        }
        coll3.insert(threeDoc);
    }

这里是我从db加载细节的地方，但由于某些原因它似乎不起作用：

private void loadData(String[] trainSeats, String[] customerName, String[] traincustomerSeats, DBCollection coll1, DBCollection coll2, DBCollection coll3) {

        Cursor cursor  = coll1.find();
        Cursor cursor2 = coll2.find();
        Cursor cursor3 = coll3.find();

        while(cursor.hasNext()){
            System.out.println(cursor.next());
        }
        while(cursor2.hasNext()){
            System.out.println(cursor2.next());
        }
        while(cursor3.hasNext()){
            System.out.println(cursor3.next());
        }
    }

这是运行时的输出-click to open output image