How to Create API in Spring Boot to Upload Image

Posted By : Gaurav Prakash Ranjan | 31-Jul-2019

Java

In this blog, I will explain how to create API using Spring Boot for uploading data and image from user to server in three steps.

1. Creating DTO And Entity Classe For Uploading Image And Data:

DTO class is used to sending and receiving data from the front-end and Entity class represents the actual data for storing data in the database.

/dto/DocumentDTO.java

import ...

/**
 * Created By G.P.Ranjan
 **/

@JsonIgnoreProperties(ignoreUnknown = true)
@Getter
@Setter
@NoArgsConstructor
@EnableStringTrimer

public class DocumentDTO {

    private Long id;

    @Valid
    @NotNull(message = "ENTER VALID DATA")
    private String name;

    private String bodyContentInHtml;

    private String documentLogo;

    public DocumentDTO(Long id,String name,String documentLogo,String bodyContentInHtml){
        this.id=id;
        this.name=name;
        this.documentLogo=documentLogo;
        this.bodyContentInHtml=bodyContentInHtml;
    }
    @Override
    public String toString(){
        return this.name;
    }
}

/entity/Document.java

import ...

/**
 * Created By G.P.Ranjan
 **/

@Entity
@Getter
@Setter
@NoArgsConstructor

public class Document{
    @Column(columnDefinition = "text")
    private String name;
    @Column(columnDefinition = "text")
    private String documentLogo;
    @Column(columnDefinition = "text")
    private String bodyContentInHtml;

    public Document(Long id,String name,String DocumentLogo,String bodyContentInHtml){
        super.id=id;
        this.name=name;
        this.documentLogo=documentLogo;
        this.bodyContentInHtml=bodyContentInHtml;
    }
}

2. Creating Service Class For Uploading Images:

In the service, we write the actual code for performing API works. In this class, we write the code on how to handle request to save image and data.

/service/DocumentService.java

import ....

/**
 * Created By G.P.Ranjan
 **/

@Service
public class DocumentService {
    @Inject
    private DocumentRepository documentRepository;
    @Inject
    private ExceptionService exceptionService;

    public DocumentDTO createDocument(DocumentDTO documentDTO) {
        if(documentDTO.getName().equals("")){
            exceptionService.duplicateDataException("Error Message");
        }
        Document document = documentRepository.findByNameIgnoreCaseAndDeletedFalse(documentDTO.getName());
        if (Optional.ofNullable(document).isPresent()) {
            exceptionService.duplicateDataException("Error Message");
        }
        Document=new Document(DocumentDTO.getId(),DocumentDTO.getName(),DocumentDTO.getDocumentLogo(),DocumentDTO.getBodyContentInHtml());
        DocumentRepository.save(Document);
        DocumentDTO.setId(Document.getId());
        return DocumentDTO;
    }

    public Map uploadDocumentLogo(MultipartFile file){
        File directory = new File(Document_LOGO_PATH);
        if (!directory.exists()) {
            try {
                directory.mkdir();
            } catch (SecurityException se) {
                return null;
            }
        }
        String fileName = DateUtils.getCurrentDate().getTime() + file.getOriginalFilename();
        final String path = Document_LOGO_PATH + File.separator + fileName;
        try (InputStream inputStream = file.getInputStream();
             FileOutputStream fileOutputStream = new FileOutputStream(new File(path))) {
            byte[] buf = new byte[1024];
            int numRead = 0;
            while ((numRead = inputStream.read(buf)) >= 0) {
                fileOutputStream.write(buf, 0, numRead);
            }
        } catch (Exception e) {
            return null;
        }
        Map responseResult = new HashMap<>();
        responseResult.put("logoUrl",fileName);
        return responseResult;
    }
}

3. Creating Controller Class For Uploading Image:

In this App, we created a DocumentController and coding for controlling the Request and call to Service Class.

/controllers/DocumentController.java

import .....

/**
 * Created By G.P.Ranjan
 **/

@RestController
public class DocumentController {
    @Inject
    private DocumentService documentService;

    @ApiOperation("Save  Document")
    @PostMapping(URL + "/document")
    public ResponseEntity createDocument(@RequestBody @Validated DocumentDTO DocumentDTO) {
        return ResponseHandler.generateResponse(HttpStatus.OK, true, documentService.createDocument(DocumentDTO));
    }

    @ApiOperation("Upload  Document Logo")
    @PostMapping(URL + "/document/logo")
    public ResponseEntity uploadDocumentLogo(@RequestParam("file") MultipartFile file) {
        return ResponseHandler.generateResponse(HttpStatus.OK, true, documentService.uploadDocumentLogo(file));
    }
}

Thanks