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java实现二维码的生成和解读

发布时间：2020-12-15 07:55:44 所属栏目：Java 来源：网络整理
导读：QRcode是日本人94年开发出来的。首先去QRCode的官网http://swetake.com/qrcode/java/qr_java.html，把要用的jar包下下来，导入到项目里去。qrcode需要设置一个版本号，这个版本号代表你生成的二维码的像素的大

QRcode是日本人94年开发出来的。首先去QRCode的官网http://swetake.com/qrcode/java/qr_java.html，把要用的jar包下下来，导入到项目里去。qrcode需要设置一个版本号，这个版本号代表你生成的二维码的像素的大小。版本1是21*21的，版本号每增加1，边长增加4。也就是说版本7的大小是45 * 45的。版本号最大值是40。另外，版本7的编码的字节数如果超过了119，那么将无法编码

1.二维码图片类实现

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package? com.reyo.code;?
???
import? java.awt.image.BufferedImage;?
import? jp.sourceforge.qrcode.data.QRCodeImage;?
???
???
public? class? TwoDimensionCodeImage? implements? QRCodeImage {?
???
???? BufferedImage bufImg;?
???
???? public? TwoDimensionCodeImage(BufferedImage bufImg) {?
???????? this .bufImg = bufImg;?
???? }?
???
???? @Override?
???? public? int? getHeight() {?
???????????? return? bufImg.getHeight();?
???? }?
???
???? @Override?
???? public? int? getPixel( int? x,? int? y) {?
???????????? return? bufImg.getRGB(x,y);?
???? }?
???
???? @Override?
???? public? int? getWidth() {?
???????????? return? bufImg.getWidth();?
???? }?
???
}?

?2.二维码编解码类实现

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package? com.reyo.code;?
???
import? java.awt.Color;?
import? java.awt.Graphics2D;?
import? java.awt.image.BufferedImage;?
import? java.io.File;?
import? java.io.IOException;?
import? java.io.InputStream;?
import? java.io.OutputStream;?
???
import? javax.imageio.ImageIO;?
???
import? jp.sourceforge.qrcode.QRCodeDecoder;?
import? jp.sourceforge.qrcode.exception.DecodingFailedException;?
???
import? com.swetake.util.Qrcode;?
???
public? class? TwoDimensionCode {?
???????
???? /**
????? * 生成二维码(QRCode)图片
????? * @param content 存储内容
????? * @param imgPath 图片路径
????? */?
???? public? void? encoderQRCode(String content,String imgPath) {?
???????? this .encoderQRCode(content,imgPath,? "png" ,? 7 );?
???? }?
???????
???? /**
????? * 生成二维码(QRCode)图片
????? * @param content 存储内容
????? * @param output 输出流
????? */?
???? public? void? encoderQRCode(String content,OutputStream output) {?
???????? this .encoderQRCode(content,output,? 7 );?
???? }?
???????
???? /**
????? * 生成二维码(QRCode)图片
????? * @param content 存储内容
????? * @param imgPath 图片路径
????? * @param imgType 图片类型
????? */?
???? public? void? encoderQRCode(String content,String imgPath,String imgType) {?
???????? this .encoderQRCode(content,imgType,? 7 );?
???? }?
???????
???? /**
????? * 生成二维码(QRCode)图片
????? * @param content 存储内容
????? * @param output 输出流
????? * @param imgType 图片类型
????? */?
???? public? void? encoderQRCode(String content,OutputStream output,String imgType) {?
???????? this .encoderQRCode(content,? 10 );?
???? }?
???
???? /**
????? * 生成二维码(QRCode)图片
????? * @param content 存储内容
????? * @param imgPath 图片路径
????? * @param imgType 图片类型
????? * @param size 二维码尺寸
????? */?
???? public? void? encoderQRCode(String content,String imgType,? int? size) {?
???????? try? {?
???????????? BufferedImage bufImg =? this .qRCodeCommon(content,size);?
???????????????
???????????? File imgFile =? new? File(imgPath);?
???????????? // 生成二维码QRCode图片?
???????????? ImageIO.write(bufImg,imgFile);?
???????? }? catch? (Exception e) {?
???????????? e.printStackTrace();?
???????? }?
???? }?
???
???? /**
????? * 生成二维码(QRCode)图片
????? * @param content 存储内容
????? * @param output 输出流
????? * @param imgType 图片类型
????? * @param size 二维码尺寸
????? */?
???? public? void? encoderQRCode(String content,? int? size) {?
???????? try? {?
???????????? BufferedImage bufImg =? this .qRCodeCommon(content,size);?
???????????? // 生成二维码QRCode图片?
???????????? ImageIO.write(bufImg,output);?
???????? }? catch? (Exception e) {?
???????????? e.printStackTrace();?
???????? }?
???? }?
???????
???? /**
????? * 生成二维码(QRCode)图片的公共方法
????? * @param content 存储内容
????? * @param imgType 图片类型
????? * @param size 二维码尺寸
????? * @return
????? */?
???? private? BufferedImage qRCodeCommon(String content,? int? size) {?
???????? BufferedImage bufImg =? null ;?
???????? try? {?
???????????? Qrcode qrcodeHandler =? new? Qrcode();?
???????????? // 设置二维码排错率，可选L(7%)、M(15%)、Q(25%)、H(30%)，排错率越高可存储的信息越少，但对二维码清晰度的要求越小?
???????????? qrcodeHandler.setQrcodeErrorCorrect( ‘M‘ );?
???????????? qrcodeHandler.setQrcodeEncodeMode( ‘B‘ );?
???????????? // 设置设置二维码尺寸，取值范围1-40，值越大尺寸越大，可存储的信息越大?
???????????? qrcodeHandler.setQrcodeVersion(size);?
???????????? // 获得内容的字节数组，设置编码格式?
???????????? byte [] contentBytes = content.getBytes( "utf-8" );?
???????????? // 图片尺寸?
???????????? int? imgSize =? 67? +? 12? * (size -? 1 );?
???????????? bufImg =? new? BufferedImage(imgSize,imgSize,BufferedImage.TYPE_INT_RGB);?
???????????? Graphics2D gs = bufImg.createGraphics();?
???????????? // 设置背景颜色?
???????????? gs.setBackground(Color.WHITE);?
???????????? gs.clearRect( 0 ,? 0 ,imgSize);?
???
???????????? // 设定图像颜色> BLACK?
???????????? gs.setColor(Color.BLACK);?
???????????? // 设置偏移量，不设置可能导致解析出错?
???????????? int? pixoff =? 2 ;?
???????????? // 输出内容> 二维码?
???????????? if? (contentBytes.length >? 0? && contentBytes.length <? 800 ) {?
???????????????? boolean [][] codeOut = qrcodeHandler.calQrcode(contentBytes);?
???????????????? for? ( int? i =? 0 ; i < codeOut.length; i++) {?
???????????????????? for? ( int? j =? 0 ; j < codeOut.length; j++) {?
???????????????????????? if? (codeOut[j][i]) {?
???????????????????????????? gs.fillRect(j *? 3? + pixoff,i *? 3? + pixoff,? 3 ,? 3 );?
???????????????????????? }?
???????????????????? }?
???????????????? }?
???????????? }? else? {?
???????????????? throw? new? Exception( "QRCode content bytes length = "? + contentBytes.length +? " not in [0,800]." );?
???????????? }?
???????????? gs.dispose();?
???????????? bufImg.flush();?
???????? }? catch? (Exception e) {?
???????????? e.printStackTrace();?
???????? }?
???????? return? bufImg;?
???? }?
???????
???? /**
????? * 解析二维码（QRCode）
????? * @param imgPath 图片路径
????? * @return
????? */?
???? public? String decoderQRCode(String imgPath) {?
???????? // QRCode 二维码图片的文件?
???????? File imageFile =? new? File(imgPath);?
???????? BufferedImage bufImg =? null ;?
???????? String content =? null ;?
???????? try? {?
???????????? bufImg = ImageIO.read(imageFile);?
???????????? QRCodeDecoder decoder =? new? QRCodeDecoder();?
???????????? content =? new? String(decoder.decode( new? TwoDimensionCodeImage(bufImg)),? "utf-8" );??
???????? }? catch? (IOException e) {?
???????????? System.out.println( "Error: "? + e.getMessage());?
???????????? e.printStackTrace();?
???????? }? catch? (DecodingFailedException dfe) {?
???????????? System.out.println( "Error: "? + dfe.getMessage());?
???????????? dfe.printStackTrace();?
???????? }?
???????? return? content;?
???? }?
???????
???? /**
????? * 解析二维码（QRCode）
????? * @param input 输入流
????? * @return
????? */?
???? public? String decoderQRCode(InputStream input) {?
???????? BufferedImage bufImg =? null ;?
???????? String content =? null ;?
???????? try? {?
???????????? bufImg = ImageIO.read(input);?
???????????? QRCodeDecoder decoder =? new? QRCodeDecoder();?
???????????? content =? new? String(decoder.decode( new? TwoDimensionCodeImage(bufImg)),? "utf-8" );??
???????? }? catch? (IOException e) {?
???????????? System.out.println( "Error: "? + e.getMessage());?
???????????? e.printStackTrace();?
???????? }? catch? (DecodingFailedException dfe) {?
???????????? System.out.println( "Error: "? + dfe.getMessage());?
???????????? dfe.printStackTrace();?
???????? }?
???????? return? content;?
???? }?
???
???? public? static? void? main(String[] args) {?
???????????
???????? String imgPath =? "C:zhaochao.png" ;????
???????? String encoderContent = "" ;?
???????? for ( int? i= 0 ;i< 40 ;i++)?
???????????????? encoderContent+= "锐洋智能" ;?
???
???????? TwoDimensionCode handler =? new? TwoDimensionCode();?????
???????????
???????? handler.encoderQRCode(encoderContent, 10 );?
???????????
???????? System.out.println( "=============编码成功！图片为于：" +imgPath+ "===============" );?
???????????
???????? String decoderContent = handler.decoderQRCode(imgPath);?
???????? System.out.println( "============解析结果如下：===============" );?
???????? System.out.println(decoderContent);?
???????? System.out.println( "=========解码成功===========" );?
???? }?
}?

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