java（基于springboot项目或maven项目均可） 操作mongodb

mymongodb.host= 10.0.0.2

mymongodb.port= 27017

mymongodb.dbname= articledb

import com.mongodb.client.gridfs.GridFSBucket;

import com.mongodb.client.gridfs.GridFSBuckets;

import lombok.Data;

import org.springframework.boot.context.properties.ConfigurationProperties;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.PropertySource;

import org.springframework.stereotype.Component;

/**

 * @Description: [mongodb工具类]

 * @Author: Jingqi Qu

 * @CreateDate: 2021/12/21 17:17

 * @UpdateUser:

 * @UpdateDate:

 * @Version: [v1.0]

 */

@Configuration

@ConfigurationProperties(prefix = "mymongodb", ignoreUnknownFields = false)

@PropertySource("classpath:config/mongodb.properties")

@Data

@Component

public class MongoDBUtil {

    private  String host;

    private  int port;

    private  String dbname;

    private static MongoDatabase mongoDatabase;

    public  MongoClient getMongoClient(){//创建方法不同版本依赖可能不同，查看源码即可 此处使用 host +默认端口号创建
　　　　　//创建client


        MongoClient mongoClient = new MongoClient(host);

        return mongoClient;

    }

    public  MongoDatabase getMongoDatabase(){

        MongoClient mongoClient = getMongoClient();


        mongoDatabase = mongoClient.getDatabase(dbname);

        return mongoDatabase;

    }

    // 使用Grid 链接指定数据库

    public  GridFSBucket getGrid(){

        MongoClient mongoClient = getMongoClient();

        MongoDatabase mongoDatabase = mongoClient.getDatabase(dbname);

        GridFSBucket gridFSBucket = GridFSBuckets.create(mongoDatabase);

        return gridFSBucket;

    }

}

import com.mongodb.MongoClient;

import com.mongodb.client.FindIterable;

import com.mongodb.client.MongoCollection;

import com.mongodb.client.MongoDatabase;

import com.mongodb.client.MongoIterable;

import com.mongodb.client.gridfs.GridFSBucket;

import com.mongodb.client.gridfs.GridFSUploadStream;

import com.mongodb.client.gridfs.model.GridFSUploadOptions;

import com.mongodb.client.model.Filters;

import com.mongodb.client.result.DeleteResult;

import com.mongodb.client.result.UpdateResult;

import org.bson.Document;

import org.bson.types.ObjectId;

import org.junit.Test;

import javax.servlet.http.HttpServletResponse;

import java.io.*;

import java.util.HashMap;

import java.util.Map;

/**

 * @Description: [一句话描述该类的功能]

 * @Author: Jingqi Qu

 * @CreateDate: 2021/12/21 17:43

 * @UpdateUser:

 * @UpdateDate:

 * @Version: [v1.0]

 */

public class TestMongo {

    // 查看mongodb所有数据库

    @Test

    public void getAllDB(){

        MongoClient  mongoClient = MongoDBUtil.getMongoClient();

        MongoIterable<String> mongoIterable = mongoClient.listDatabaseNames();

        for(String db:mongoIterable){

            System.out.println(db);

        }

    }

    // 查看指定数据库下的所有集合

    @Test

    public void getCollections(){

        MongoDatabase db = MongoDBUtil.getMongoDatabase();

        MongoIterable<String> nameList = db.listCollectionNames();

        for(String collectionsName :nameList){

            System.out.println(collectionsName);

        }

    }

    // 创建集合

    @Test

    public void createCollections(){

        MongoDatabase db = MongoDBUtil.getMongoDatabase();

        db.createCollection("threeCollection");

    }

    // 删除集合

    @Test

    public void removeCollections(){

        MongoDatabase db = MongoDBUtil.getMongoDatabase();

        MongoCollection<Document> collection =  db.getCollection("threeCollection");

        collection.drop();

    }

    // 根据集合名获取所有文档

    @Test

    public void findDocumentByCollectionName(){

        MongoDatabase db = MongoDBUtil.getMongoDatabase();

        MongoCollection<Document> collection =  db.getCollection("threeCollection");

        FindIterable<Document> doc =  collection.find();

        for(Document document :doc){

            System.out.println(document);

        }

    }

    // 插入文档

    @Test

    public void insertDocumentByCollectionName(){

        MongoDatabase db = MongoDBUtil.getMongoDatabase();

        MongoCollection<Document> collection =  db.getCollection("threeCollection");

        Document doc = new Document();

        Map<String,String> map = new HashMap<String, String>();

        map.put("class","222");

        //默认是个ObjectId对象，此处设置为string，否则无法更新

        doc.append("_id","44444");

        doc.append("name","tom3");

        doc.append("age","68");

        collection.insertOne(doc);

    }

    // 更新文档

    @Test

    public void updateDocumentByCollectionName(){

        MongoDatabase db = MongoDBUtil.getMongoDatabase();

        MongoCollection<Document> collection =  db.getCollection("threeCollection");

        Document doc = new Document("class","888");

        UpdateResult a = collection.updateOne(Filters.eq("class","222"),new Document("$set",doc));

        System.out.println(a);

    }

    // 删除文档

    @Test

    public void removeDocumentByCollectionName(){

        MongoDatabase db = MongoDBUtil.getMongoDatabase();

        MongoCollection<Document> collection =  db.getCollection("threeCollection");

        DeleteResult res = collection.deleteOne(Filters.eq("_id","61c2c911136fb13d507f5b4f"));

        System.out.println(res);

    }

    // MongoDB GridFS  存图片

    @Test

    public void test(){

        GridFSBucket grid = MongoDBUtil.getGrid();

        GridFSUploadOptions options = new GridFSUploadOptions();

        options.chunkSizeBytes(358400);//定义chunk大小

        GridFSUploadStream stream = grid.openUploadStream("test.png",options); //创建上传流

        InputStream in = null;

        try{

            File file = new File("F:\\项目资料\\图片\\banner1.png");

            in = new FileInputStream(file);

            int tempbyte;

            while ((tempbyte = in.read()) != -1) {

                stream.write(tempbyte);

            }

            in.close();

            stream.close();

            System.out.println("文件id："+stream.getFileId());

        }catch (IOException e){

            e.printStackTrace();

        }

    }

    // MongoDB GridFS  跟据文档id取图片

    @Test

    public void test2(HttpServletResponse resp){

        GridFSBucket grid = MongoDBUtil.getGrid();

        GridFSUploadOptions options = new GridFSUploadOptions();

        try{

            OutputStream out = resp.getOutputStream();

            grid.downloadToStream(new ObjectId("61c305e0136fb133fcf3f247"),out);

        }catch (IOException e){

        }

    }

}