1.pom.xml檔案配置

2.工具類

import cn.hutool.core.codec.Base64Decoder;
import cn.hutool.core.util.StrUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.ImageType;
import org.apache.pdfbox.rendering.PDFRenderer;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;

/**

• TODO

• @Author: DYS

• @date 2021/8/4 18:02

• @描述:
  */
  @Slf4j
  public class Base64Utils {

  /**

  • @描述: 根據base64編碼生成圖片，儲存在Path中
  • @Date: 2021/8/5 13:08
  • @param base64Code:
  • @param filePath:
  • @param picName:
  • @return boolean
  • @Description: //TODO PC002
  • @Author: DYS
    **/
    public static boolean base64ToPic(String base64Code, String filePath, String picName) {
    if (base64Code == null) {
    return false;
    }
    //檔案不存在
    File existsFilePath = new File(filePath);
    if (!existsFilePath.exists()) {
    existsFilePath.mkdirs();
    }
    // String handledBase64Code = "data:image/png;base64," + base64PdfToJpgBase64(base64Code);
    String handledBase64Code =base64PdfToJpgBase64(base64Code);
    // Base64解碼
    // 替換掉多餘的空格
    String replace = handledBase64Code.replaceAll(" ", "");
    BASE64Decoder decoder = new BASE64Decoder();
    try {
    //Base64解碼
    byte[] b = decoder.decodeBuffer(replace);
    for (int i = 0; i < b.length; ++i) {
    if (b[i] < 0) {//調整異常資料
    b[i] += 256;
    }
    }
    //生成jpeg圖片
    String path = filePath + "/" + picName + ".png";
    OutputStream out = new FileOutputStream(path);
    out.write(b);
    out.flush();
    out.close();
    return true;
    } catch (Exception e) {
    StringWriter stringWriter = new StringWriter();
    PrintWriter printWriter = new PrintWriter(stringWriter);
    e.printStackTrace();
    e.printStackTrace(printWriter);
    log.error("base64編碼生成圖片 error >>> " + stringWriter.toString());
    return false;
    }
    }

  // 將pdf的base64編碼格式轉為img的base64編碼格式併合成一張圖片：
  public static String base64PdfToJpgBase64(String base64Pdf) {
  if (StrUtil.isEmpty(base64Pdf)) {
  return null;
  }
  String jpg_base64 = null;
  // Base64Decoder decoder = new Base64Decoder();
  try {
  // Base64解碼
  byte[] pdf_bytes = Base64Decoder.decode(base64Pdf);
  PDDocument doc = PDDocument.load(pdf_bytes);
  int size = doc.getNumberOfPages();
  /影象合併使用的引數/
  //定義寬度
  int width = 0;
  // 儲存一張圖片中的RGB資料
  int[] singleImgRGB;
  // 定義高度，後面用於疊加
  int shiftHeight = 0;
  //儲存每張圖片的畫素值
  BufferedImage imageResult = null;
  // 利用PdfBox生成影象
  PDDocument pdDocument = doc;
  PDFRenderer renderer = new PDFRenderer(pdDocument);
  /根據總頁數, 按照50頁生成一張長圖片的邏輯, 進行拆分/
  // 每50頁轉成1張圖片
  int pageLength = size; //有多少轉多少
  // 總計迴圈的次數
  int totalCount = pdDocument.getNumberOfPages() / pageLength + 1;
  for (int m = 0; m < totalCount; m++) {
  for (int i = 0; i < pageLength; i++) {
  int pageIndex = i + (m * pageLength);
  if (pageIndex == pdDocument.getNumberOfPages()) {
  System.out.println("迴圈次數 m = " + m);
  break;
  }
  // 96為圖片的dpi，dpi越大，則圖片越清晰，圖片越大，轉換耗費的時間也越多
  BufferedImage image = renderer.renderImageWithDPI(pageIndex, 150, ImageType.RGB);
  int imageHeight = image.getHeight();
  int imageWidth = image.getWidth();
  if (i == 0) {
  //計算高度和偏移量
  //使用第一張圖片寬度;
  width = imageWidth;
  // 儲存每頁圖片的畫素值
  // 加個判斷：如果m次迴圈後所剩的圖片總數小於pageLength，則圖片高度按剩餘的張數繪製，否則會出現長圖片下面全是黑色的情況
  if ((pdDocument.getNumberOfPages() - m * pageLength) < pageLength) {
  imageResult = new BufferedImage(width, imageHeight * (pdDocument.getNumberOfPages() - m * pageLength), BufferedImage.TYPE_INT_RGB);
  } else {
  imageResult = new BufferedImage(width, imageHeight * pageLength, BufferedImage.TYPE_INT_RGB);
  }
  } else {
  // 將高度不斷累加
  shiftHeight += imageHeight;
  }
  singleImgRGB = image.getRGB(0, 0, width, imageHeight, null, 0, width);
  imageResult.setRGB(0, shiftHeight, width, imageHeight, singleImgRGB, 0, width);
  }
  // 這個很重要，下面會有說明
  shiftHeight = 0;
  }
  pdDocument.close();
  ByteArrayOutputStream baos = new ByteArrayOutputStream();//io流
  ImageIO.write(imageResult, "jpg", baos);//寫入流中
  byte[] jpg_Bytes = baos.toByteArray();//轉換成位元組
  BASE64Encoder encoder = new BASE64Encoder();
  jpg_base64 = encoder.encodeBuffer(jpg_Bytes).trim();//轉換成base64串
  jpg_base64 = jpg_base64.replaceAll("\n", "").replaceAll("\r", "");//刪除 \r\n
  baos.close();
  doc.close();
  } catch (IOException e) {
  e.printStackTrace();
  }
  return jpg_base64;
  }

  /**

  • 圖片生成base64編碼
  • @param imgPath
  • @return
    */
    public static String PicToBase64(String imgPath) {
    String result = "";
    File imgFile = new File(imgPath);
    if (!imgFile.exists()) {
    System.out.println("非法路徑");
    return result;
    }
    InputStream in = null;
    byte[] data = null;
    //讀取圖片位元組陣列
    try {
    in = new FileInputStream(imgFile);
    data = new byte[in.available()];
    in.read(data);
    in.close();
    } catch (IOException e) {
    e.printStackTrace();
    }
    //對位元組陣列Base64編碼
    BASE64Encoder encoder = new BASE64Encoder();
    return encoder.encode(data);//返回Base64編碼過的位元組陣列字串
    }

  public static byte[] base64ToImgByteArray(String base64) throws IOException {
  sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();
  //因為引數base64來源不一樣，需要將附件資料替換清空掉。如果此入參來自canvas.toDataURL("image/png");
  base64 = base64.replaceAll("data:image/png;base64,", "");
  //base64解碼並轉為二進位制陣列
  byte[] bytes = decoder.decodeBuffer(base64);
  for (int i = 0; i < bytes.length; ++i) {
  if (bytes[i] < 0) {// 調整異常資料
  bytes[i] += 256;
  }
  }
  return bytes;
  }

}