java 生成二维码实例

最近有点时间想学点东西，想做个简单的系统，现在登录的时候使用扫描二维码获取验证码登录，于是就有了下面的一些代码

首先要导入pom依赖

<dependency>
     <groupId>com.google.zxing</groupId>
     <artifactId>core</artifactId>
     <version>3.3.0</version>
</dependency>

这个是goole提供的一些包

第一个类是goole提供帮主类 画出图片

package com.cmbchina.ccd.itpm.baffle.util;

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import com.google.zxing.LuminanceSource;

public class BufferedImageLuminanceSource extends LuminanceSource {

  private final BufferedImage image;
  private final int left;
  private final int top;

  public BufferedImageLuminanceSource(BufferedImage image) {
    this(image, 0, 0, image.getWidth(), image.getHeight());
  }

  public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {
    super(width, height);

    int sourceWidth = image.getWidth();
    int sourceHeight = image.getHeight();
    if (left + width > sourceWidth || top + height > sourceHeight) {
      throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
    }

    for (int y = top; y < top + height; y++) {
      for (int x = left; x < left + width; x++) {
        if ((image.getRGB(x, y) & 0xFF000000) == 0) {
          image.setRGB(x, y, 0xFFFFFFFF); // = white
        }
      }
    }

    this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
    this.image.getGraphics().drawImage(image, 0, 0, null);
    this.left = left;
    this.top = top;
  }

  public byte[] getRow(int y, byte[] row) {
    if (y < 0 || y >= getHeight()) {
      throw new IllegalArgumentException("Requested row is outside the image: " + y);
    }
    int width = getWidth();
    if (row == null || row.length < width) {
      row = new byte[width];
    }
    image.getRaster().getDataElements(left, top + y, width, 1, row);
    return row;
  }

  public byte[] getMatrix() {
    int width = getWidth();
    int height = getHeight();
    int area = width * height;
    byte[] matrix = new byte[area];
    image.getRaster().getDataElements(left, top, width, height, matrix);
    return matrix;
  }

  public boolean isCropSupported() {
    return true;
  }

  public LuminanceSource crop(int left, int top, int width, int height) {
    return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
  }

  public boolean isRotateSupported() {
    return true;
  }

  public LuminanceSource rotateCounterClockwise() {
    int sourceWidth = image.getWidth();
    int sourceHeight = image.getHeight();
    AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
    BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
    Graphics2D g = rotatedImage.createGraphics();
    g.drawImage(image, transform, null);
    g.dispose();
    int width = getWidth();
    return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
  }

}

生成图片工具类

package com.cmbchina.ccd.itpm.baffle.util;

import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.Hashtable;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class QRCodeUtil {
  private static final String CHARSET = "utf-8";
  private static final String FORMAT_NAME = "JPG";
  // 二维码尺寸
  private static final int QRCODE_SIZE = 300;
  // LOGO宽度
  private static final int WIDTH = 60;
  // LOGO高度
  private static final int HEIGHT = 60;

  private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception {
    Hashtable hints = new Hashtable();
    hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
    hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
    hints.put(EncodeHintType.MARGIN, 1);
    BitMatrix bitMatrix =
        new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints);
    int width = bitMatrix.getWidth();
    int height = bitMatrix.getHeight();
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    for (int x = 0; x < width; x++) {
      for (int y = 0; y < height; y++) {
        image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
      }
    }
    if (imgPath == null || "".equals(imgPath)) {
      return image;
    }
    // 插入图片
    QRCodeUtil.insertImage(image, imgPath, needCompress);
    return image;
  }

  private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception {
    File file = new File(imgPath);
    if (!file.exists()) {
      System.err.println("" + imgPath + "  该文件不存在！");
      return;
    }
    Image src = ImageIO.read(new File(imgPath));
    int width = src.getWidth(null);
    int height = src.getHeight(null);
    if (needCompress) { // 压缩LOGO
      if (width > WIDTH) {
        width = WIDTH;
      }
      if (height > HEIGHT) {
        height = HEIGHT;
      }
      Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
      BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
      Graphics g = tag.getGraphics();
      g.drawImage(image, 0, 0, null); // 绘制缩小后的图
      g.dispose();
      src = image;
    }
    // 插入LOGO
    Graphics2D graph = source.createGraphics();
    int x = (QRCODE_SIZE - width) / 2;
    int y = (QRCODE_SIZE - height) / 2;
    graph.drawImage(src, x, y, width, height, null);
    Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
    graph.setStroke(new BasicStroke(3f));
    graph.draw(shape);
    graph.dispose();
  }

  /**
   * @param content 编码到二维码中的内容
   * @param imgPath 要嵌入二维码的图片路径，如果不写或者为null则生成一个没有嵌入图片的纯净的二维码
   * @param destPath 生成的二维码的存放路径
   * @param needCompress true：表示将嵌入二维码的图片进行压缩，如果为“false”则表示不压缩
   * @param request
   * @param response 设置图片返回前端展示
   * @throws Exception
   */
  public static void encode(String content, String imgPath, String destPath, boolean needCompress,
               HttpServletRequest request, HttpServletResponse response) throws Exception {
    BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
    mkdirs(destPath);
    // String file = new Random().nextInt(99999999)+".jpg";
    // ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
    ImageIO.write(image, FORMAT_NAME, new File(destPath));
    response.setContentType("image/jpeg");
    // 设置响应头控制浏览器不要缓存
    response.setDateHeader("expries", -1);
    response.setHeader("Cache-Control", "no-cache");
    response.setHeader("Pragma", "no-cache");
    ImageIO.write(image, FORMAT_NAME, response.getOutputStream());
  }

  public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
    BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
    return image;
  }

  public static void mkdirs(String destPath) {
    File file = new File(destPath);
    // 当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．(mkdir如果父目录不存在则会抛出异常)
    if (!file.exists() && !file.isDirectory()) {
      file.mkdirs();
    }
  }

  public static void encode(String content, String imgPath, String destPath) throws Exception {
    QRCodeUtil.encode(content, imgPath, destPath, false);
  }
  // 被注释的方法
  /*
   * public static void encode(String content, String destPath, boolean
   * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
   * needCompress); }
   */

  public static void encode(String content, String destPath) throws Exception {
    QRCodeUtil.encode(content, null, destPath, false);
  }

  public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
      throws Exception {
    BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
    ImageIO.write(image, FORMAT_NAME, output);
  }

  public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
    BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
    mkdirs(destPath);
    // String file = new Random().nextInt(99999999)+".jpg";
    // ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
    ImageIO.write(image, FORMAT_NAME, new File(destPath));

  }

  public static void encode(String content, OutputStream output) throws Exception {
    QRCodeUtil.encode(content, null, output, false);
  }

  public static String decode(File file) throws Exception {
    BufferedImage image;
    image = ImageIO.read(file);
    if (image == null) {
      return null;
    }
    BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
    BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
    Result result;
    Hashtable hints = new Hashtable();
    hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
    result = new MultiFormatReader().decode(bitmap, hints);
    String resultStr = result.getText();
    return resultStr;
  }

  public static String decode(String path) throws Exception {
    return QRCodeUtil.decode(new File(path));
  }

}

controller

package com.cmbchina.ccd.itpm.baffle.controller;

import com.cmbchina.ccd.itpm.baffle.util.QRCodeUtil;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Random;

/**
 * @Author zly
 * @Date 2020/6/24 15:54
 */
@RestController
@RequestMapping("image")
public class ImageController {
  @GetMapping("getImage")
  public void getImage(HttpServletRequest request, HttpServletResponse response) throws Exception {
    String text = "http://101.132.36.16";
    // 嵌入二维码的图片路径
    String imgPath = "F:/qrCode/Koala.jpg";
    // 生成的二维码的路径及名称
    String destPath = "F:/qrCode/qrcode/jam.jpg";
    //这里可以根据业务逻辑产生二维码内容 这里我是使用随机数1000-9999
    int i = (int) (Math.random() * 9000 + 1000);

    //生成二维码并返回前端

    QRCodeUtil.encode("" + i, imgPath, destPath, true, request, response);

  }
}

二维码示例

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原文链接：https://www.cnblogs.com/blackCatFish/p/13188476.html