Java生成二維碼

1，下載jar包(QRCode.jar)

maven依賴

1. <dependency>

2. <groupId>QRCode</groupId>

3. <artifactId>QRCode</artifactId>

4. <version>3.0</version>

5. </dependency>

2，編寫實體類實現二維碼的生成

二維碼工具類

1. public class CreateQRCode {

2.  

3. /**

4. * 建立二維碼

5. * @param qrData 生成二維碼中要存儲的信息

6. * @param path 二維碼圖片存儲路徑 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');//糾錯等級（分爲L、M、H三個等級）

13. qrcode.setQrcodeEncodeMode('B');//N表明數字，A表明a-Z，B表明其它字符

14. qrcode.setQrcodeVersion(7);//版本

15.  

16. //設置一下二維碼的像素

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. //繪圖

21. Graphics2D gs = bufferedImage.createGraphics();

22. gs.setBackground(Color.WHITE);

23. gs.setColor(Color.BLACK);

24. gs.clearRect(0, 0, width, height);//清除下畫板內容

25.  

26. //設置下偏移量,若是不加偏移量，有時會致使出錯。

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. * 解析二維碼（QRCode）

52. *

53. * @param imgPath 圖片路徑

54. * @return

55. */

56. public static String decoderQRCode(String imgPath) {

57. //QRCode 二維碼圖片的文件

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. }

 

二維碼基礎類

1. class TwoDimensionCodeImage implements QRCodeImage {

2. //BufferedImage做用將一幅圖片加載到內存中

3. BufferedImage bufImg;

4. public TwoDimensionCodeImage(BufferedImage bufImg) {

5. this.bufImg = bufImg;

6. }

7.  

8. @Override

9. public int getWidth() {

10. return bufImg.getWidth();//返回像素寬度

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);//獲得長寬值，即像素值，i,i1表明像素值

21. }

22. }

3.controller調用

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. * 建立二維碼

17. */

18. @Controller

19. @RequestMapping("/qrcode")

20. public class QrcodeController {

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

22. private String qrcodePath; //二維碼存儲路徑

23.  

24. /**

25. * 建立二維碼

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. * 解析二維碼

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. }

此時已生成一張名爲qrcode.png的二維碼圖片：