原创

使用java访问mongodb存取文件

创建一个maven项目，加入以下依赖

        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongo-java-driver</artifactId>
            <version>3.6.3</version>
        </dependency>

创建一个TestMongo.java，内容如下：

import com.mongodb.DB;
import com.mongodb.Mongo;
import com.mongodb.gridfs.GridFS;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSInputFile;
import org.bson.types.ObjectId;

import java.io.File;


public class MongoTest {

    public static void main(String[] args) {
//        upload("C:/Users/zhangli/Desktop/1.png");
        download("5e4be8c63930f446e42b8c65","C:/Users/zhangli/Desktop/1.png");
    }


    public static void download(String id,String filepath) {
        try {
            Mongo db = new Mongo("127.0.0.1", 27017);
            DB mydb = db.getDB("tf");
            GridFS myFS = new GridFS(mydb);
            GridFSDBFile gridFSDBFile = myFS.findOne(new ObjectId(id));
            gridFSDBFile.writeTo(filepath);
            db.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void upload(String filepath) {
        try {
            Mongo db = new Mongo("127.0.0.1", 27017);
            DB mydb = db.getDB("tf");
            File f = new File(filepath);
            GridFS myFS = new GridFS(mydb);
            GridFSInputFile inputFile = myFS.createFile(f);
            inputFile.save();
            System.out.println(inputFile.getId());
            db.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}