How to upload and retrieve file in mongodb in spring boot application without using GridFSTemplate?

Question

I want to upload files and retrieve them from mongodb in spring boot application. But I don't want to use GridFSTemplate because my file size will not be greater than 16 MB. I am not choosing GridFSTemplate because none of the requirements mentioned in link https://docs.mongodb.com/manual/core/gridfs/#faq-developers-when-to-use-gridfs do not meet my requirements. Is working with Document to save files and retrieve them using MongoTemplate a good approach? MyDocument definition will look like

@Document
public class MyDocument {
    @Id
    private String id;
    private String emailId;
    private String docType;
    @CreatedDate
    private DateTime created;
    @LastModifiedDate
    private DateTime modified;
    private File document;
}

Storing file

MyDocument document = new MyDocument();
document.setEmailId("[email protected]");
document.setDocType("passport");
document.setDocument(file);
mongoTemplate.insert(document);

I want to store file along with some information like email. Later I will retrieve this file based on email parameter. Please suggest if this approach is good or any other better solution is appreciated.

Boles

Answer 1

I could finally figure out the way to store files without using GridFS in mongodb. First thing you have to note that we have to store byte[] representation of file.

import org.bson.types.Binary;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;
@Document
public class DemoDocument {
    @Id
    @Field
    private String id;

    @Field
    private String emailId;

    @Field
    private String docType;

    @Field
    private Binary file;
}

Make sure your file object is org.bson.types.Binary. Following is my controller code to save object in monogodb.

@PostMapping("/upload")
public String singleFileUpload(@RequestParam("file") MultipartFile multipart, @RequestParam("email") String email) {
    try {
        DemoDocument demoDocument = new DemoDocument();
        demoDocument.setEmailId(email);
        demoDocument.setDocType("pictures");
        demoDocument.setDocument(new Binary(BsonBinarySubType.BINARY, multipart.getBytes()));
        mongoTemplate.insert(demoDocument);
        System.out.println(demoDocument);
    } catch (Exception e) {
        e.printStackTrace();
        return "failure";
    }
    return "success";
}

You can retrieve this object from mongodb as following.

@PostMapping("/retrieve")
public String retrieveFile(@RequestParam("email") String email){
    DemoDocument demoDocument = mongoTemplate.findOne(new BasicQuery("{emailId : \""+email+"\", docType : \"pictures\"}"), DemoDocument.class);
    System.out.println(demoDocument);
    Binary document = demoDocument.getDocument();
    if(document != null) {
        FileOutputStream fileOuputStream = null;
        try {
            fileOuputStream = new FileOutputStream(RETRIEVE_FOLDER + "prof_pic.jpg");
            fileOuputStream.write(document.getData());
        } catch (Exception e) {
            e.printStackTrace();
            return "failure";
        } finally {
            if (fileOuputStream != null) {
                try {
                    fileOuputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                    return "failure";
                }
            }
        }
    }
    return "success";
}

Please note this is just sample working code for understanding. It can be written in fully object oriented way keeping design principles in mind.

Boles

you really saved my time with your example, everywhere i searched only i could see GridFS GridFS GridFS.... – Umbrella