KotlinでExcelにQRコードを描く

QRKotlin.kt

package link.arata.kexcel

import com.google.zxing.BarcodeFormat
import com.google.zxing.EncodeHintType
import com.google.zxing.client.j2se.MatrixToImageWriter
import com.google.zxing.qrcode.QRCodeWriter
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel
import link.arata.kexcelapi.get
import org.apache.poi.ss.usermodel.CellStyle
import org.apache.poi.xssf.usermodel.XSSFColor
import org.apache.poi.xssf.usermodel.XSSFWorkbook
import java.awt.Color
import java.io.File
import java.util.*


fun main(args: Array<String>) {
    var workbook: XSSFWorkbook = XSSFWorkbook()
    var sheet = workbook.createSheet()
    workbook.setSheetName(0, "QRコード")
    sheet.setDisplayGridlines(false)

    val contents = "http://webarata.hatenablog.jp"
    val format = BarcodeFormat.QR_CODE
    val width = 40
    val height = width

    val rowHeight = 500f / width

    val hints = Hashtable<EncodeHintType, ErrorCorrectionLevel>()
    hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M)
    val writer = QRCodeWriter()
    val bitMatrix = writer.encode(contents, format, width, height, hints)
    val image = MatrixToImageWriter.toBufferedImage(bitMatrix);

    for (y in 0..height - 1) {
        sheet[y].heightInPoints = rowHeight
    }
    for (x in 0..width - 1) {
        sheet.setColumnWidth(x, (rowHeight * 41f).toInt())
    }

    val style = workbook.createCellStyle()
    style.fillPattern = CellStyle.SOLID_FOREGROUND
    style.setFillForegroundColor(XSSFColor(Color(0, 0, 0)))

    for (y in 0..height - 1) {
        for (x in 0..width - 1) {
            if (image.getRGB(x, y) == -16777216) {
                sheet[x, y].cellStyle = style
            }
        }
    }

    workbook.write(File("image.xlsx").outputStream());
    workbook.close()
}