OCRController 1

OCRController.kt

import com.google.cloud.vision.v1.AnnotateImageRequest
import com.google.cloud.vision.v1.Feature
import com.google.cloud.vision.v1.Image
import com.google.cloud.vision.v1.ImageAnnotatorClient
import com.google.protobuf.ByteString
import org.springframework.beans.factory.annotation.Value
import org.springframework.http.MediaType
import org.springframework.http.ResponseEntity
import org.springframework.validation.annotation.Validated
import org.springframework.web.bind.annotation.PostMapping
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RequestPart
import org.springframework.web.bind.annotation.RestController
import org.springframework.web.multipart.MultipartFile
import java.io.FileInputStream
import javax.validation.constraints.NotNull

@RestController
@RequestMapping("/api/ocr")
@Validated
class OCRController {
    @Value("\${google.cloud.credentials.path}")
    private lateinit var credentialsPath: String

    @PostMapping(consumes = [MediaType.MULTIPART_FORM_DATA_VALUE])
    fun ocr(@NotNull @RequestPart("file") file: MultipartFile): ResponseEntity<String> {
        val imageBytes = ByteString.copyFrom(file.bytes)
        val image = Image.newBuilder().setContent(imageBytes).build()

        val settings = ImageAnnotatorSettings.newBuilder()
            .setCredentialsProvider { FixedCredentialsProvider.create(ServiceAccountCredentials.fromStream(FileInputStream(credentialsPath))) }
            .build()

        val imageAnnotatorClient = ImageAnnotatorClient.create(settings)

        val imageRequest = AnnotateImageRequest.newBuilder()
            .addFeatures(Feature.newBuilder().setType(Feature.Type.TEXT_DETECTION))
            .setImage(image)
            .build()
        val response = imageAnnotatorClient.batchAnnotateImages(listOf(imageRequest))
        val annotation = response.responsesList[0].textAnnotationsList[0]

        imageAnnotatorClient.close()

        return ResponseEntity.ok(annotation.description)
    }
}