private ServerAddress serverAddress = new ServerAddress("101.132.251.198", 27017);
    private MongoCredential credential = MongoCredential.createCredential("root", "tutorial", "root".toCharArray());
    CodecRegistry pojoCodecRegistry = fromRegistries(MongoClientSettings.getDefaultCodecRegistry(),
            fromProviders(PojoCodecProvider.builder().automatic(true).build()));
    MongoClientSettings settings = MongoClientSettings.builder()
            .codecRegistry(pojoCodecRegistry)
            .credential(credential)
            .applyToClusterSettings(builder -> builder.hosts(Arrays.asList(serverAddress)))
            .build();
    MongoClient mongoClient = MongoClients.create(settings);

import com.mongodb.Block;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.result.DeleteResult;
import com.mongodb.client.result.UpdateResult;
import org.bson.codecs.configuration.CodecRegistry;
import org.bson.codecs.pojo.PojoCodecProvider;
import java.util.List;
import static com.mongodb.client.model.Filters.*;
import static com.mongodb.client.model.Updates.*;
import static java.util.Arrays.asList;
import static org.bson.codecs.configuration.CodecRegistries.fromProviders;
import static org.bson.codecs.configuration.CodecRegistries.fromRegistries;

@Data
@AllArgsConstructor
public final class Person {
    private ObjectId id;
    private String name;
    private int age;
    private Address address;
    public Person() {
    }
    public Person(String name, int age, Address address) {
        this.name = name;
        this.age = age;
        this.address = address;
    }
}
@Data
@AllArgsConstructor
public final class Address {
    private String street;
    private String city;
    private String zip;
    public Address(){}
}

Creating a Custom CodecRegistry

• PojoCodecProvider.builder()

        CodecRegistry pojoCodecRegistry = fromRegistries(MongoClientSettings.getDefaultCodecRegistry(),
                fromProviders(PojoCodecProvider.builder().automatic(true).build()));

  Using the CodecRegistry

• You can set it when instantiating a MongoClient object:

    MongoClientSettings settings = MongoClientSettings.builder()
            .codecRegistry(pojoCodecRegistry)
            .credential(credential)
            .applyToClusterSettings(builder -> builder.hosts(Arrays.asList(serverAddress)))
            .build();
    MongoClient mongoClient = MongoClients.create(settings);

• You can use an alternative CodecRegistry with a MongoDatabase:

  database = database.withCodecRegistry(pojoCodecRegistry);

• You can use an alternative CodecRegistry with a MongoCollection:

  collection = collection.withCodecRegistry(pojoCodecRegistry);

  Inserting a POJO into MongoDB

  MongoCollection<Person> collection = database.getCollection("people", Person.class);

  Insert a Person

  ```java Person ada = new Person(“Ada Byron”, 20, new Address(“St James Square”, “London”, “W1”));

collection.insertOne(ada);

<a name="ghxzq"></a>
### Insert Many Persons
```java
        List<Person> people = Arrays.asList(
                new Person("Charles Babbage", 45, new Address("5 Devonshire Street", "London", "W11")),
                new Person("Alan Turing", 28, new Address("Bletchley Hall", "Bletchley Park", "MK12")),
                new Person("Timothy Berners-Lee", 61, new Address("Colehill", "Wimborne", null))
        );
        collection.insertMany(people);

Query the Collection

    @Test
    public void testQuery() {
        Block<Person> printBlock = new Block<Person>() {
            @Override
            public void apply(Person person) {
                System.out.println(person);
            }
        };
        collection.find().forEach(printBlock);
    }

Specify a Query Filter

在查询Pojo时，您必须查询文档字段名称，而不是Pojo的属性名称。默认情况下它们是相同的，但是可以更改POJO属性名的映射方式。

Get A Single Person That Matches a Filter

        Person somebody = collection.find(eq("address.city", "Wimborne")).first();
        System.out.println(somebody);

Get All Person Instances That Match a Filter

collection.find(gt("age", 30)).forEach(printBlock);

Update Documents

Update a Single Person

        collection.updateOne(eq("name", "Ada Byron"), Updates.combine(Updates.set("age", 23), Updates.set("name", "Ada Lovelace")));
        collection.find(eq("name", "Ada Lovelace")).forEach(printBlock);

Update Multiple Persons

        UpdateResult updateResult = collection.updateMany(not(eq("zip", null)), Updates.set("zip", null));
        System.out.println(updateResult.getModifiedCount());

Replace a Single Person

collection.replaceOne(eq("name", "Ada Lovelace"), ada);

Delete Documents

        DeleteResult deleteResult = collection.deleteMany(eq("address.city", "London"));
        System.out.println(deleteResult.getDeletedCount());