1，下载jar包(QRCode.jar)

maven依赖

1. <dependency>

2. <groupId>QRCode</groupId>

3. <artifactId>QRCode</artifactId>

4. <version>3.0</version>

5. </dependency>

2，编写实体类实现二维码的生成

二维码工具类

1. public class CreateQRCode {

2.  

3. /**

4. * 创建二维码

5. * @param qrData 生成二维码中要存储的信息

6. * @param path 二维码图片存储路径 eg："D:/qrcode.png"

7. * @throws Exception

8. */

9. public static boolean creatQrcode(String qrData, String path) {

10. try {

11. Qrcode qrcode = new Qrcode();

12. qrcode.setQrcodeErrorCorrect('M');//纠错等级（分为L、M、H三个等级）

13. qrcode.setQrcodeEncodeMode('B');//N代表数字，A代表a-Z，B代表其它字符

14. qrcode.setQrcodeVersion(7);//版本

15.  

16. //设置一下二维码的像素

17. int width = 67 + 12 * (7 - 1);

18. int height = 67 + 12 * (7 - 1);

19. BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

20. //绘图

21. Graphics2D gs = bufferedImage.createGraphics();

22. gs.setBackground(Color.WHITE);

23. gs.setColor(Color.BLACK);

24. gs.clearRect(0, 0, width, height);//清除下画板内容

25.  

26. //设置下偏移量,如果不加偏移量，有时会导致出错。

27. int pixoff = 2;

28.  

29. byte[] d = qrData.getBytes("utf-8");

30. if (d.length > 0 && d.length < 120) {

31. boolean[][] s = qrcode.calQrcode(d);

32. for (int i = 0; i < s.length; i++) {

33. for (int j = 0; j < s.length; j++) {

34. if (s[j][i]) {

35. gs.fillRect(j * 3 + pixoff, i * 3 + pixoff, 3, 3);

36. }

37. }

38. }

39. }

40. gs.dispose();

41. bufferedImage.flush();

42. ImageIO.write(bufferedImage, "png", new File(path));

43. return true;

44. } catch (IOException e) {

45. e.printStackTrace();

46. return false;

47. }

48. }

49.  

50. /**

51. * 解析二维码（QRCode）

52. *

53. * @param imgPath 图片路径

54. * @return

55. */

56. public static String decoderQRCode(String imgPath) {

57. //QRCode 二维码图片的文件

58. File imageFile = new File(imgPath);

59. BufferedImage bufImg = null;

60. String content = null;

61. try {

62. bufImg = ImageIO.read(imageFile);

63. QRCodeDecoder decoder = new QRCodeDecoder();

64. content = new String(decoder.decode(new TwoDimensionCodeImage(bufImg)), "utf-8");

65. } catch (IOException e) {

66. System.out.println("Error: " + e.getMessage());

67. e.printStackTrace();

68. } catch (DecodingFailedException dfe) {

69. System.out.println("Error: " + dfe.getMessage());

70. dfe.printStackTrace();

71. }

72. return content;

73. }

74.  

75. }

二维码基础类

1. class TwoDimensionCodeImage implements QRCodeImage {

2. //BufferedImage作用将一幅图片加载到内存中

3. BufferedImage bufImg;

4. public TwoDimensionCodeImage(BufferedImage bufImg) {

5. this.bufImg = bufImg;

6. }

7.  

8. @Override

9. public int getWidth() {

10. return bufImg.getWidth();//返回像素宽度

11. }

12.  

13. @Override

14. public int getHeight() {

15. return bufImg.getHeight();//返回像素高度

16. }

17.  

18. @Override

19. public int getPixel(int i, int i1) {

20. return bufImg.getRGB(i, i1);//得到长宽值，即像素值，i,i1代表像素值

21. }

22. }

3.controller调用

1. package com.st.project.controller;

2.  

3. import com.st.project.common.AjaxResult;

4. import org.springframework.beans.factory.annotation.Value;

5. import org.springframework.stereotype.Controller;

6. import org.springframework.web.bind.annotation.PostMapping;

7. import org.springframework.web.bind.annotation.RequestMapping;

8. import org.springframework.web.bind.annotation.ResponseBody;

9.  

10. import javax.servlet.http.HttpServletRequest;

11.  

12. import static com.st.project.common.CreateQRCode.creatQrcode;

13. import static com.st.project.common.CreateQRCode.decoderQRCode;

14.  

15. /**

16. * 创建二维码

17. */

18. @Controller

19. @RequestMapping("/qrcode")

20. public class QrcodeController {

21. @Value("${portals.upload.image.path}")

22. private String qrcodePath; //二维码存储路径

23.  

24. /**

25. * 创建二维码

26. * @return

27. */

28. @ResponseBody

29. @PostMapping("/add.dd")

30. public AjaxResult addQrcode(HttpServletRequest request){

31. AjaxResult ajaxResult = new AjaxResult();

32. ajaxResult.setState(false);

33. String qrData=request.getParameter("qrData");

34. String qrSuffix=request.getParameter("qrSuffix");

35. String qrcode=System.currentTimeMillis()+"."+qrSuffix;

36. String path=qrcodePath+qrcode;

37. boolean getQrcode=creatQrcode(qrData,path);

38. if(getQrcode==true){

39. ajaxResult.setState(true);

40. ajaxResult.setData(qrcode);

41. }

42. return ajaxResult;

43. }

44.  

45. /**

46. * 解析二维码

47. * @return

48. */

49. @ResponseBody

50. @PostMapping("/decoder.dd")

51. public AjaxResult decoderQrcode(HttpServletRequest request){

52. AjaxResult ajaxResult = new AjaxResult();

53. ajaxResult.setState(false);

54. String qrcode=request.getParameter("qrcode");

55.  

56. String qrData=decoderQRCode(qrcodePath+qrcode);

57. if(qrData!=null && !"".equals(qrData)){

58. ajaxResult.setState(true);

59. ajaxResult.setData(qrData);

60. }

61. return ajaxResult;

62. }

63.  

64. }

此时已生成一张名为qrcode.png的二维码图片：