java 如何做二维码

你需要将`ZXing`库添加到你的项目中。如果你使用的是Maven，可以在`pom.xml`文件中添加以下依赖：

```xml

com.google.zxing

core

3.4.1

com.google.zxing

javase

3.4.1

```

```java

import com.google.zxing.BarcodeFormat;

import com.google.zxing.EncodeHintType;

import com.google.zxing.MultiFormatWriter;

import com.google.zxing.WriterException;

import com.google.zxing.common.BitMatrix;

import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import java.io.ByteArrayOutputStream;

import java.util.HashMap;

import java.util.Map;

public class QRCodeGenerator {

public static byte[] generateQRCodeImage(String text, int width, int height) throws WriterException {

Map hints = new HashMap<>();

hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

hints.put(EncodeHintType.MARGIN, 1);

MultiFormatWriter multiFormatWriter = new MultiFormatWriter();

BitMatrix bitMatrix = multiFormatWriter.encode(text, BarcodeFormat.QR_CODE, width, height, hints);

int[] pixels = new int[width height];

for (int y = 0; y < height; y++) {

for (int x = 0; x < width; x++) {

if (bitMatrix.get(x, y)) {

pixels[y width + x] = 0xFF000000;