Mongodb-GridFS 文件存储

最新推荐文章于 2020-10-30 08:25:05 发布

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#java #mongodb #MongoDB GridFS 图片文件

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本文介绍如何使用Java操作MongoDB的GridFS存储系统，详细讲解GridfsTest.java代码示例，涵盖文件上传、下载及管理操作。

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>

GridfsTest.java

import com.mongodb.client.gridfs.GridFSBucket;
import com.mongodb.client.gridfs.GridFSDownloadStream;
import com.mongodb.client.gridfs.model.GridFSFile;
import org.apache.commons.io.IOUtils;
import org.bson.types.ObjectId;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.gridfs.GridFsResource;
import org.springframework.data.mongodb.gridfs.GridFsTemplate;
import org.springframework.test.context.junit4.SpringRunner;
import java.io.*;

@RunWith(SpringRunner.class)
@SpringBootTest
public class GridfsTest {

    @Autowired
    private  GridFsTemplate gridFsTemplate;
    @Autowired
    private GridFSBucket gridFSBucket;

    @Test
    public void uploadFile() throws FileNotFoundException {
        String pdfPath = "D:\\pdfRender\\古代埃及文明 封面.pdf";
        File file = new File(pdfPath);
        // 获得提交的文件名
        String fileName = file.getName();
        // 获得文件输入流
        InputStream ins = new FileInputStream(file);
        // 获得文件类型
        String contentType = "pdf";
        // 将文件存储到mongodb中,mongodb 将会返回这个文件的具体信息
        ObjectId objectId = gridFsTemplate.store(ins, fileName, contentType);
    }

    @Test
    public void download() throws IOException {
        String id="5eeb4bdfa610dd4b54583265";
        String md5="f3976c520026d2287c3746f4bc84f91e";
        //根据id查询文件
        GridFSFile gridFSFile =
                gridFsTemplate.findOne(Query.query(Criteria.where("md5").is(md5)));
        //打开流下载对象
        GridFSDownloadStream downloadStream =
                gridFSBucket.openDownloadStream(gridFSFile.getObjectId());
        //获取流对象
        GridFsResource gridFsResource=new GridFsResource(gridFSFile,downloadStream);

        String pdfPath = "D:\\pdfRender\\古代埃及文明 封面 download.pdf";
        File file = new File(pdfPath);
        OutputStream output = new FileOutputStream(file);

        IOUtils.copy(gridFsResource.getInputStream(), output);
        output.close();
    }
}