之前说了微信小程序生成微信小程序码，现在说一下普通的二维码的生成。
（这些都是亲测，都可以使用）
导入依赖(maven)
com.google.zxing
core
3.4.1
com.google.zxing
javase
3.4.1
自定义一个工具类
package com.miniapp.common.utils;
import cn.hutool.core.codec.Base64;
import cn.hutool.core.util.StrUtil;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.oned.Code128Writer;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import lombok.extern.slf4j.Slf4j;
import org.apache.catalina.security.SecurityUtil;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;
@Slf4j
public class QrCodeUtil {
private static final int WIDTH = 300;
private static final int HEIGHT = 300;
private static final String FORMAT = "png";
private static final Map HINTS = new HashMap();
static {
// 字符编码
HINTS.put(EncodeHintType.CHARACTER_SET, "utf-8");
// 容错等级 L、M、Q、H 其中 L 为最低, H 为最高
HINTS.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
// 二维码与图片边距
HINTS.put(EncodeHintType.MARGIN, 2);
}
public static void generateBarCodeFile(String content, String paths) {
Code128Writer writer = new Code128Writer();
BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.CODE_128, WIDTH, HEIGHT, HINTS);
Path path = Paths.get(paths);
if (!StrUtil.isEmpty(content)) {
try {
MatrixToImageWriter.writeToPath(bitMatrix, FORMAT, path);
} catch (IOException e) {
log.error("生成条形码失败：{}", e.getMessage());
}
}
}
public static OutputStream generateBarCodeStream(String content, HttpServletResponse response) {
Code128Writer writer = new Code128Writer();
OutputStream outputStream = null;
BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.CODE_128, WIDTH, HEIGHT, HINTS);
if (!StrUtil.isEmpty(content)) {
try {
// 字节输出流
outputStream = response.getOutputStream();
MatrixToImageWriter.writeToStream(bitMatrix, FORMAT, outputStream);
return outputStream;
} catch (IOException e) {
log.error("生成条形码失败：{}", e.getMessage());
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch (IOException e) {
log.error("流关闭失败：{}", e.getMessage());
}
}
}
}
return null;
}
public static String generateBarCodeBase64(String content) {
String base64;
ByteArrayOutputStream os = new ByteArrayOutputStream();
Code128Writer writer = new Code128Writer();
BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.CODE_128, WIDTH, HEIGHT, HINTS);
if (!StrUtil.isEmpty(content)) {
try {
BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix);
ImageIO.write(bufferedImage, FORMAT, os);
base64 = Base64.encode(os.toByteArray());
return base64;
} catch (Exception e) {
log.error("生成二维码失败：{}", e.getMessage());
} finally {
try {
os.flush();
os.close();
} catch (IOException e) {
log.error("流关闭失败：{}", e.getMessage());
}
}
}
return null;
}
public static void generateQrCodeFile(String content, String paths) {
MultiFormatWriter writer = new MultiFormatWriter();
if (!StrUtil.isEmpty(content)) {
try {
// 字节输出流
BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, HINTS);
Path path = Paths.get(paths);
MatrixToImageWriter.writeToPath(bitMatrix, FORMAT, path);
} catch (Exception e) {
log.error("生成二维码失败：{}", e.getMessage());
}
}
}
public static OutputStream generateQrCodeStream(String content, HttpServletResponse response) {
MultiFormatWriter writer = new MultiFormatWriter();
OutputStream outputStream = null;
if (!StrUtil.isEmpty(content)) {
try {
// 字节输出流
BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, HINTS);
outputStream = response.getOutputStream();
MatrixToImageWriter.writeToStream(bitMatrix, FORMAT, outputStream);
return outputStream;
} catch (Exception e) {
log.error("生成二维码失败：{}", e.getMessage());
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch (IOException e) {
log.error("流关闭失败：{}", e.getMessage());
}
}
}
}
return null;
}
public static String generateQrCodeBase64(String content) {
String base64;
ByteArrayOutputStream os = new ByteArrayOutputStream();
if (!StrUtil.isEmpty(content)) {
try {
QRCodeWriter writer = new QRCodeWriter();
BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, HINTS);
BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix);
ImageIO.write(bufferedImage, FORMAT, os);
base64 = Base64.encode(os.toByteArray());
return base64;
} catch (Exception e) {
log.error("生成二维码失败：{}", e.getMessage());
} finally {
try {
os.flush();
os.close();
} catch (IOException e) {
log.error("流关闭失败：{}", e.getMessage());
}
}
}
return null;
}
}
这些分别生成条形码和二维码，包括生成本地的，base64的，和文件流的，按需求进行调用方法即可。
注意：生成文件流的需要传参HttpServletResponse 这一点需要注意
类似
@GetMapping("getQrcode")
public OutputStream getQrcode (HttpServletResponse response) throws IOException {
OutputStream s = CodeUtil.generateQrCodeStream("测试文件流", response);
return s;
}
扩展
如果你想让你的二维码内容进行加密，你完全可以使用hutool包的加密工具类进行加密解密。
也可以选择对称加密和非对称加密，这是你自己进行取舍的。
package com.study.mybatisplus.utils;
import cn.hutool.core.util.StrUtil;
import cn.hutool.crypto.SecureUtil;
import cn.hutool.crypto.symmetric.DES;
import cn.hutool.crypto.symmetric.SymmetricAlgorithm;
public class SecurityUtil {
private static final String STR_KEY = "mybatis_plus_security_key";
private static byte[] getKey() {
byte[] byteKey = StrUtil.bytes(STR_KEY);
return SecureUtil.generateKey(SymmetricAlgorithm.DES.getValue(), byteKey).getEncoded();
}
public static String getEncryptStr(String content) {
DES des = SecureUtil.des(SecurityUtil.getKey());
return des.encryptHex(content);
}
public static String getDecryptStr(String encryptStr) {
DES des = SecureUtil.des(SecurityUtil.getKey());
return des.decryptStr(encryptStr);
}
}
具体的细节就需要你自己慢慢进行取舍了。
