Java实现生成二维码展示到浏览器的示例代码
要实现在浏览器展示二维码,那么首先需要html文件,通过Java生成二维码的工具类,在controller层调用接口,就可以实现在浏览器上展示二维码。
html文件内容如下:
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org" xmlns:http="http://www.w3.org/1999/xhtml" xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity4"> <head> <meta charset="UTF-8"> <title>二维码</title> <script th:src="@{../js/jquery-3.1.1.js}"></script> <style type="text/css"> #qrcode-mask{ margin-left: 40px; margin-top: 30px; } #code-panel{ width: 280px; height: 320px; border: 1px solid #e1e1e1; margin: 0 auto; margin-top: 30px; background-color: rgba(255,215,255,0.25); box-shadow: -4px -4px 6px rgba(0,0,0,0.35) inset; } /*rgba(25,252,205,0.15);*/ #desc{ color: #717375; font-size: 14px; text-align: center; } </style> <script type="text/javascript"> onload=function(){ $.ajax({ type: 'POST', url: '/qrcode/img', dataType: 'json', data: '', success:function (result) { if (result.code == 1){ $("#qrcode").attr('src','data:image/png;base64,'+result.data.img); }else{ alert(result.info); } }, error:function (result) { alert("获取失败"); } }); } </script> </head> <body> <div id="code-panel"> <div id="qrcode-mask"> <img id="qrcode" alt="" src=""> </div> <div id="desc"> 扫描并关注<br> 微信公众平台 </div> </div> </body> </html>
接着在Controller层实现一个接口,代码如下:
import java.util.HashMap; import java.util.Map; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import com.suntree.commons.ApiResult; import com.suntree.utils.QRCodeUtil; @SpringBootApplication @RestController @RequestMapping("/qrcode") public class QRCodeContoller { /** * 获取二维码图片 * @return */ @PostMapping("/img") public ApiResult getQRCodeImage() { ApiResult result=new ApiResult(); Map<String,Object> img=new HashMap<>(); String content="https://guangz-myblog.oss-cn-shenzhen.aliyuncs.com/private/user/%E5%88%98%E5%85%89%E5%AE%97/ff52da04-009d-49b4-9601-936c33bb0673.png"; String imgPath="https://guangz-myblog.oss-cn-shenzhen.aliyuncs.com/private/user/%E5%88%98%E5%85%89%E5%AE%97/ff52da04-009d-49b4-9601-936c33bb0673.png"; String base64=QRCodeUtil.getImageToBase64(content, imgPath, true); img.put("img", base64); return result.success(img); } }
这个获取的是二维码图片的base64;
再接下来就是实现生成二维码的工具类,代码如下:
import java.awt.BasicStroke; 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.ByteArrayOutputStream; import java.io.File; import java.io.IOException; import java.io.OutputStream; import java.util.HashMap; import java.util.Map; import javax.imageio.ImageIO; 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.client.j2se.BufferedImageLuminanceSource; import com.google.zxing.common.BitMatrix; import com.google.zxing.common.HybridBinarizer; import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel; import sun.misc.BASE64Encoder; public class QRCodeUtil { private static final String CHARSET = "utf-8"; private static final String FORMAT_NAME = "PNG"; // 二维码尺寸 private static final int QRCODE_SIZE = 200; // LOGO宽度 private static final int WIDTH = 60; // LOGO高度 private static final int HEIGHT = 60; /** * 创建图片 * @param content * @param imgPath * @param needCompress * @return * @throws Exception */ private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception { Map<EncodeHintType,Object> hints = new HashMap<EncodeHintType, Object>(); 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; } /** * 插入图片 * @param source * @param imgPath * @param needCompress * @throws Exception */ 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(file); 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(); Graphics2D g2 = (Graphics2D) tag.getGraphics(); g2.drawImage(image, 0, 0, null); // 绘制缩小后的图 g2.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(); } /** * * 生成二维码并放入本地 * @param content * @param imgPath * @param destPath * @param needCompress * @throws Exception */ public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); mkdirs(destPath); ImageIO.write(image, FORMAT_NAME, new File(destPath)); } 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); } 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, 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; Map<DecodeHintType,Object> hints = new HashMap<DecodeHintType, Object>(); hints.put(DecodeHintType.CHARACTER_SET, CHARSET); result = new MultiFormatReader().decode(bitmap, hints); String resultStr = result.getText(); return resultStr; } /** * 生成二维码图片转base64 * * @param content * @param imgPath * @param needCompress * @return */ public static String getImageToBase64(String content, String imgPath, boolean needCompress) { ByteArrayOutputStream out=null; try { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); out = new ByteArrayOutputStream(); ImageIO.write(image,"png",out); byte[] b = out.toByteArray(); BASE64Encoder encoder = new BASE64Encoder(); return encoder.encode(b);//生成base64编码 } catch (Exception e) { e.printStackTrace(); }finally{ if(out!=null) { try { out.close(); } catch (IOException e) { e.printStackTrace(); } } } return null; } }
最后实现WebMvcConfigurer接口,这样就可以在浏览器上展示二维码了。
大家可以自己去试试,望大家多多支持!
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