servlet
String code =""; code = req.getParameter("code"); if (code == null && !"".equals(code)) { code = "duwenlei"; } try { TestImg.generateImg(code); resp.setHeader("Content-Type", "image/png"); InputStream in = new FileInputStream(new File("f://test.png")); ServletOutputStream out = resp.getOutputStream(); int len; byte[] buffer = new byte[1024]; while ((len = in.read(buffer)) > 0) { out.write(buffer, 0, len); } out.flush(); out.close(); in.close(); } catch (Exception e) { e.printStackTrace(); }
utils
public class TestImg { private static final int BLACK = 0xff000000; private static final int WHITE = 0xFFFFFFFF; public static void generateImg(String code) throws Exception{ File file = new File("f://test.png"); TestImg test = new TestImg(); test.encode(code, file,BarcodeFormat.QR_CODE, 200, 200, null); test.decode(file); } public void encode(String contents, File file, BarcodeFormat format, int width, int height, Map<EncodeHintType, ?> hints) throws Exception { BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, format, width, height); writeToFile(bitMatrix, "png", file); } /** * 生成二维码图片<br> * * @param matrix * @param format * 图片格式 * @param file * 生成二维码图片位置 * @throws IOException */ public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException { BufferedImage image = toBufferedImage(matrix); ImageIO.write(image, format, file); } /** * 生成二维码内容<br> * * @param matrix * @return */ public static BufferedImage toBufferedImage(BitMatrix matrix) { int width = matrix.getWidth(); int height = matrix.getHeight(); BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB); for (int x = 0; x < width; x++) { for (int y = 0; y < height; y++) { image.setRGB(x, y, matrix.get(x, y) == true ? BLACK : WHITE); } } return image; } /** * 解析QRCode二维码 */ @SuppressWarnings("unchecked") public void decode(File file) { try { BufferedImage image; try { image = ImageIO.read(file); if (image == null) { System.out.println("Could not decode image"); } LuminanceSource source = new BufferedImageLuminanceSource(image); BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source)); Result result; @SuppressWarnings("rawtypes") Hashtable hints = new Hashtable(); //解码设置编码方式为：utf-8 hints.put(DecodeHintType.CHARACTER_SET, "utf-8"); result = new MultiFormatReader().decode(bitmap, hints); String resultStr = result.getText(); System.out.println("解析后内容：" + resultStr); } catch (IOException ioe) { System.out.println(ioe.toString()); } catch (ReaderException re) { System.out.println(re.toString()); } } catch (Exception ex) { System.out.println(ex.toString()); } } }
jsp
<body>
<h1>TestWeb</h1>
<input type="text" name="code" id="codeValue"/><br/><img src="/TestWeb/TestImgServlet" width="200" height="200" onclick="change(this)"/>
</body>
<script type="text/javascript">
function change(obj){
var code = document.getElementById("codeValue").value;
var codes = obj.src ;
if(codes.indexOf("?") != -1){
var url = codes.substring(0,codes.indexOf("?"));
obj.src = url+"?code="+code;
return;
}
obj.src = obj.src+"?code="+code;
}
</script>