JAVA 生成二维码

1.java这边的话生成二维码有很多开发的jar包如zxing,qrcode.q前者是谷歌开发的后者则是小日本开发的，这里的话我使用zxing的开发包来弄

2.先下载zxing开发包，这里用到的只是core那个jar包

3.使用zxing开发还需要一个类，代码如下

package org.lxh;
import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import java.io.File;
import java.io.OutputStream;
import java.io.IOException;
import java.awt.image.BufferedImage;

public final class MatrixToImageWriter {

private static final int BLACK = 0xFF000000;
private static final int WHITE = 0xFFFFFFFF;

private MatrixToImageWriter() {}

public static BufferedImage toBufferedImage(BitMatrix matrix) {
int width = matrix.getWidth();
int height = matrix.getHeight();
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
}
}
return image;
}

public static void writeToFile(BitMatrix matrix, String format, File file)
throws IOException {
BufferedImage image = toBufferedImage(matrix);
if (!ImageIO.write(image, format, file)) {
throw new IOException("Could not write an image of format " + format + " to " + file);
}
}

public static void writeToStream(BitMatrix matrix, String format, OutputStream stream)
throws IOException {
Buffered
4000
Image image = toBufferedImage(matrix);
if (!ImageIO.write(image, format, stream)) {
throw new IOException("Could not write an image of format " + format);
}
}

}

4.借助上面的类生成二维码

package org.lxh;

import java.io.File;
import java.util.Hashtable;

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;

public class Test {

/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
String text = "http://www.baidu.com";
int width = 300;
int height = 300;
//二维码的图片格式
String format = "gif";
Hashtable hints = new Hashtable();
//内容所使用编码
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
BarcodeFormat.QR_CODE, width, height, hints);
//生成二维码--生成图片
File outputFile = new File("d:"+File.separator+"new.gif");
MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);

/*另外一种方式：使用流输出图片
String url = "www.baidu.com";
int width = 300;
int height = 300;
//二维码的图片格式
String format = "jpg";
Hashtable hints = new Hashtable();
//内容所使用编码
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
BitMatrix bitMatrix = new MultiFormatWriter().encode( url , BarcodeFormat.QR_CODE, width, height , hints);
HttpServletResponse response = this.getResponse();
response.setHeader("Pragma","no-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
response.setContentType("image/jpeg");
ServletOutputStream sos = null;
try {
sos = response.getOutputStream();
MatrixToImageWriter.writeToStream(bitMatrix, format , sos);
} catch (Exception e) {
throw new RuntimeException(e);
}
finally {
if (sos != null)
try {sos.close();} catch (IOException e) {e.printStackTrace();}
}

}
*/
}