Java后台直接生成二维码介绍

Java后台直接生成二维码

 

1、其实jquery也可以直接生成二维码的，但我测试的时候，二维码生成后太模糊，难以识别。所以在这里介绍在后来生成二维码的方式。

2、不善于文字描述，直接上代码了。

 

  1 import java.awt.Graphics2D;
  2 import java.awt.geom.AffineTransform;
  3 import java.awt.image.BufferedImage;
  4 import java.io.File;
  5 import java.io.IOException;
  6 import java.io.OutputStream;
  7 import java.util.HashMap;
  8 import java.util.Hashtable;
  9 import java.util.Map;
 10  
 11 import javax.imageio.ImageIO;
 12 import javax.servlet.http.HttpServletResponse;
 13  
 14 import org.slf4j.Logger;
 15 import org.slf4j.LoggerFactory;
 16  
 17 import com.google.zxing.BarcodeFormat;
 18 import com.google.zxing.Binarizer;
 19 import com.google.zxing.BinaryBitmap;
 20 import com.google.zxing.DecodeHintType;
 21 import com.google.zxing.EncodeHintType;
 22 import com.google.zxing.LuminanceSource;
 23 import com.google.zxing.MultiFormatReader;
 24 import com.google.zxing.MultiFormatWriter;
 25 import com.google.zxing.Result;
 26 import com.google.zxing.common.BitMatrix;
 27 import com.google.zxing.common.HybridBinarizer;
 28 import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
 29  
 30 /**
 31  * 
Title:QRCodeUtil 
 32  * 
Description: 二维码生成工具类
 33  * @author Administrator
 34  * @version 
 35  * @since 
 36  */
 37 public final class QRCodeUtil extends LuminanceSource {
 38  
 39     private static final Logger logger = LoggerFactory.getLogger(QRCodeUtil.class);
 40  
 41     // 二维码颜色
 42     private static final int BLACK = 0xFF000000;
 43     // 二维码颜色
 44     private static final int WHITE = 0xFFFFFFFF;
 45  
 46     private final BufferedImage image;
 47     private final int left;
 48     private final int top;
 49  
 50     public QRCodeUtil(BufferedImage image) {
 51         this(image, 0, 0, image.getWidth(), image.getHeight());
 52     }
 53  
 54     public QRCodeUtil(BufferedImage image, int left, int top, int width, int height) {
 55         super(width, height);
 56         int sourceWidth = image.getWidth();
 57         int sourceHeight = image.getHeight();
 58         if (left + width > sourceWidth || top + height > sourceHeight) {
 59             throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
 60         }
 61         for (int y = top; y < top + height; y++) {
 62             for (int x = left; x < left + width; x++) {
 63                 if ((image.getRGB(x, y) & 0xFF000000) == 0) {
 64                     image.setRGB(x, y, 0xFFFFFFFF); // = white
 65                 }
 66             }
 67         }
 68         this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
 69         this.image.getGraphics().drawImage(image, 0, 0, null);
 70         this.left = left;
 71         this.top = top;
 72     }
 73  
 74     @Override
 75     public byte[] getRow(int y, byte[] row) {
 76         if (y < 0 || y >= getHeight()) {
 77             throw new IllegalArgumentException("Requested row is outside the image: " + y);
 78         }
 79         int width = getWidth();
 80         if (row == null || row.length < width) {
 81             row = new byte[width];
 82         }
 83         image.getRaster().getDataElements(left, top + y, width, 1, row);
 84         return row;
 85     }
 86  
 87     @Override
 88     public byte[] getMatrix() {
 89         int width = getWidth();
 90         int height = getHeight();
 91         int area = width * height;
 92         byte[] matrix = new byte[area];
 93         image.getRaster().getDataElements(left, top, width, height, matrix);
 94         return matrix;
 95     }
 96  
 97     @Override
 98     public boolean isCropSupported() {
 99         return true;
100     }
101  
102     @Override
103     public LuminanceSource crop(int left, int top, int width, int height) {
104         return new QRCodeUtil(image, this.left + left, this.top + top, width, height);
105     }
106  
107     @Override
108     public boolean isRotateSupported() {
109         return true;
110     }
111  
112     @Override
113     public LuminanceSource rotateCounterClockwise() {
114         int sourceWidth = image.getWidth();
115         int sourceHeight = image.getHeight();
116         AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
117         BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
118         Graphics2D g = rotatedImage.createGraphics();
119         g.drawImage(image, transform, null);
120         g.dispose();
121         int width = getWidth();
122         return new QRCodeUtil(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
123     }
124  
125     /**
126      * @param matrix
127      * @return
128      */
129     private static BufferedImage toBufferedImage(BitMatrix matrix) {
130         int width = matrix.getWidth();
131         int height = matrix.getHeight();
132         BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
133         for (int x = 0; x < width; x++) {
134             for (int y = 0; y < height; y++) {
135                 image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
136             }
137         }
138         return image;
139     }
140  
141     /**
142      * 生成二维码图片
143      * 
144      * @param matrix
145      * @param format
146      * @param file
147      * @throws IOException
148      */
149     public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
150         BufferedImage image = toBufferedImage(matrix);
151         if (!ImageIO.write(image, format, file)) {
152             throw new IOException("Could not write an image of format " + format + " to " + file);
153         }
154     }
155  
156     /**
157      * 生成二维码图片流
158      * 
159      * @param matrix
160      * @param format
161      * @param stream
162      * @throws IOException
163      */
164     public static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException {
165         BufferedImage image = toBufferedImage(matrix);
166         if (!ImageIO.write(image, format, stream)) {
167             throw new IOException("Could not write an image of format " + format);
168         }
169     }
170  
171     /**
172      * 根据内容，生成指定宽高、指定格式的二维码图片
173      *
174      * @param text   内容
175      * @param width  宽
176      * @param height 高
177      * @param format 图片格式
178      * @return 生成的二维码图片路径
179      * @throws Exception
180      */
181     private static String generateQRCode(String text, int width, int height, String format, String pathName)
182             throws Exception {
183         Hashtable hints = new Hashtable();
184         hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定编码格式
185         hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级
186         hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4
187         BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);
188         File outputFile = new File(pathName);
189         writeToFile(bitMatrix, format, outputFile);
190         return pathName;
191     }
192  
193     /**
194      * 输出二维码图片流
195      * 
196      * @param text 二维码内容
197      * @param width 二维码宽
198      * @param height 二维码高
199      * @param format 图片格式eg: png, jpg, gif
200      * @param response HttpServletResponse
201      * @throws Exception
202      */
203     public static void generateQRCode(String text, int width, int height, String format, HttpServletResponse response)
204             throws Exception {
205         Hashtable hints = new Hashtable();
206         hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定编码格式
207         hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级
208         hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4
209         BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);
210         writeToStream(bitMatrix, format, response.getOutputStream());
211     }
212  
213     /**
214      * 解析指定路径下的二维码图片
215      *
216      * @param filePath 二维码图片路径
217      * @return
218      */
219     public static String parseQRCode(String filePath) {
220         String content = "";
221         try {
222             File file = new File(filePath);
223             BufferedImage image = ImageIO.read(file);
224             LuminanceSource source = new QRCodeUtil(image);
225             Binarizer binarizer = new HybridBinarizer(source);
226             BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);
227             Map hints = new HashMap();
228             hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");
229             MultiFormatReader formatReader = new MultiFormatReader();
230             Result result = formatReader.decode(binaryBitmap, hints);
231  
232             logger.info("result 为：" + result.toString());
233             logger.info("resultFormat 为：" + result.getBarcodeFormat());
234             logger.info("resultText 为：" + result.getText());
235             // 设置返回值
236             content = result.getText();
237         } catch (Exception e) {
238             logger.error(e.getMessage());
239         }
240         return content;
241     }
242  
243     public static void main(String[] args) {
244         String text = "hello world!"; // 随机生成验证码
245         System.out.println("随机码： " + text);
246         int width = 100; // 二维码图片的宽
247         int height = 100; // 二维码图片的高
248         String format = "png"; // 二维码图片的格式
249  
250         try {
251             // 生成二维码图片，并返回图片路径
252             String pathName = generateQRCode(text, width, height, format, "D:/new.png");
253             System.out.println("生成二维码的图片路径： " + pathName);
254  
255             String content = parseQRCode(pathName);
256             System.out.println("解析出二维码的图片的内容为： " + content);
257         } catch (Exception e) {
258             e.printStackTrace();
259         }
260     }
261  
262 }

3、需要添加的依赖

1         
2             com.google.zxing
3             core
4             3.3.0
5         
6  

 

转载于:https://www.cnblogs.com/c2013/p/10249972.html