今天学习了mongodb数据库的Java代码连接和编程操作，并成功用java客户端编程连接了mongodb数据库

下面是操作步骤以及代码部分：

（1）添加数据：English:45 Math:89  Computer:100

代码：

public class MongoDBTest {

    private MongoClient mongoClient = null;
    private MongoDatabase database = null;

    @Before
    public void init() {
        // 连接mongodb服务器，自带连接池效果
        mongoClient = MongoClients.create("mongodb://192.168.10.102:27017");
        // 获取数据库，如果数据库不存在，为该数据库存储数据是自动创建
        database = mongoClient.getDatabase("student");
    }

    @After
    public void close() {
        if (mongoClient != null) {
            mongoClient.close();
        }
    }

    @Test
    public void test01() {
        MongoCollection<Document> collection = database.getCollection("student");
        Document document = new Document("name", "scofield")
                .append("score", new Document("English", 45).append("Math", 89).append("Computer", 100));
        collection.insertOne(document);

        System.out.println("添加成功");

        FindIterable<Document> documents = collection.find();
        for (Document document1 : documents) {
            System.out.println(document1.toJson());
        }


    }
}

（2）获取scofield的所有成绩成绩信息(只显示score列)

public class MongoDBTest {

    private MongoClient mongoClient = null;
    private MongoDatabase database = null;

    @Before
    public void init() {
        // 连接mongodb服务器，自带连接池效果
        mongoClient = MongoClients.create("mongodb://49.7.220.30:27017");
        // 获取数据库，如果数据库不存在，为该数据库存储数据是自动创建
        database = mongoClient.getDatabase("gazikel");
    }

    @After
    public void close() {
        if (mongoClient != null) {
            mongoClient.close();
        }
    }

    @Test
    public void test02() {
        MongoCollection<Document> collection = database.getCollection("student");
        FindIterable<Document> projection = collection.find(new Document("name", "scofield")).projection(new Document("score", 1).append("_id", 0));
        for (Document document : projection) {
            System.out.println(document.toJson());
        }
    }
}