以SpringBoot项目为例

第一步：引入依赖

<!-- https://mvnrepository.com/artifact/org.mongodb/mongo-java-driver -->
        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongo-java-driver</artifactId>
            <version>3.6.1</version>
        </dependency>
        

第二步：添加config

import com.mongodb.MongoClient;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.gridfs.GridFSBucket;
import com.mongodb.client.gridfs.GridFSBuckets;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Arrays;

@Configuration
class MongoConfig {

    @Value("${spring.data.mongodb.ip}")
    private String ip;

    @Value("${spring.data.mongodb.port}")
    private Integer port;

    @Value("${spring.data.mongodb.username}")
    private String username;

    @Value("${spring.data.mongodb.password}")
    private String password;

    @Value("${spring.data.mongodb.database}")
    private String database;

    @Bean
    public MongoClient getMongoClient(){
        MongoCredential credential = MongoCredential.createCredential(username, "admin", password.toCharArray());
//        MongoClient mongoClient = new MongoClient(new ServerAddress(ip, port));  //没有密码用这个
        MongoClient mongoClient = new MongoClient(new ServerAddress(ip, port), Arrays.asList(credential));
        return  mongoClient;
    }

    @Bean
    public MongoDatabase getMongoDatabase(){
        return getMongoClient().getDatabase(database);
    }

    @Bean
    public GridFSBucket getGridFSBucket(){
        return GridFSBuckets.create(getMongoDatabase(), database);
    }

    @Bean
    public MongoCollection<Object> getMongoCollection(){
       return getMongoDatabase().getCollection("Data", Object.class);
    }
}

第三步：添加配置文件

spring:
  data:
    mongodb:
      ip: 127.0.0.1
      port: 27017
      username: root
      password: root
      database: FileData //可自己定义

第四步：注入gridFSBucket，编写接口

@Resource
private GridFSBucket gridFSBucket;


	@PostMapping("pullFile")
    public void pullFile() throws IOException {

        Map<String, String> metaData = new HashMap<>();
        metaData.put("tags", "Data"); //Data可自己定义

        File file = new File("D:\\File\\2021-06");//文件夹路径，可写Linux，此处以Windows为例
        File[] tempList = file.listFiles();

        InputStream in = null;

        for (File temp : tempList) {

            String fileName = temp.getName();

            GridFSUploadOptions options = new GridFSUploadOptions()
            .chunkSizeBytes(1024*1024*1024)
            .metadata(new Document("type", "0"));//设置存入后type的值，可以自己定义

            InputStream ins = new FileInputStream(temp);

            gridFSBucket.uploadFromStream(fileName, ins, options);

            in = new FileInputStream(temp);

        }

        tempList.clone();
        in.close();

    }

第五步：访问接口测试

报错
Payload document size of is larger than maximum of 16777216.
从字面意思理解，就是我们值设置太大了，
.chunkSizeBytes(1024*1024*1024)改为.chunkSizeBytes(1024*1024)

重新运行，如果有些文件内容过大，就耐心等待一会，打开mongo连接的工具看结果

测试成功！