JAVA 生成二维码

https://files.cnblogs.com/files/xuejianxiyang/core.jar.rar  导入jar包

//标准
boolean bl = false;

//生成内容
String text =url;

//二维码宽度和高度
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;

try {
bitMatrix = new MultiFormatWriter().encode(text,
BarcodeFormat.QR_CODE, width, height, hints);

Desktop dtp = (Desktop) Executions.getCurrent().getDesktop();
String realPath = dtp.getSession().getWebApp().getRealPath("/file/download/");
//生成二维码
File outputFile = new File(realPath+news.getId()+".jpg");
try {
MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

bl = true;
showPic="/file/download/"+news.getId()+".jpg";

} catch (WriterException e) {
// TODO Auto-generated catch block
bl=false;
e.printStackTrace();
}

if(bl){
System.out.println("成功");
}
else{
System.out.println("失败");
}

/**
* 生成二维码 
*
*/
public class MatrixToImageWriter {

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

public static BufferedImage toBufferedImage(BitMatrix matrix) {
int[] rec = matrix.getEnclosingRectangle();
int resWidth = rec[2] + 1;
int resHeight = rec[3] + 1;
BitMatrix resMatrix = new BitMatrix(resWidth, resHeight);
resMatrix.clear();
for (int i = 0; i < resWidth; i++) {
for (int j = 0; j < resHeight; j++) {
if (matrix.get(i + rec[0], j + rec[1])) {
resMatrix.set(i, j);
}
}
}
int width = resMatrix.getWidth();
int height = resMatrix.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, resMatrix.get(x, y) == true ? 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 writeToOutputStream(BitMatrix matrix, String format,OutputStream os) throws IOException{
BufferedImage image = toBufferedImage(matrix);
if (!ImageIO.write(image, format, os)) {
throw new IOException("Could not write an image of format " + format + " to " + os);
}
}

public static void writeToOutputStream(String value, String format,OutputStream os,int width,int height)
throws IOException{
Map<EncodeHintType,String> hints = new Hashtable<>();
try {
BitMatrix bitMatrix = new MultiFormatWriter().encode(value,BarcodeFormat.QR_CODE, width, height, hints);
writeToOutputStream(bitMatrix,format,os);
} catch (WriterException e) {
e.printStackTrace();
}
}

/**
* 获得需要生成图片的格式类型
* @param pathname 路径和图片的名称与格式
* @return 图片的格式 如:jpg,gif 等等,如果字符串不正确则返回NULL
*/
public static String getImageFormat(String pathname){
int num = pathname.lastIndexOf("."); //获得字符串中最后一次出现【.】的下标数
if(num > -1){
return pathname.substring(num+1);
}else{
return null;
}
}

/**
* 将字符串生成二维码，并存放到指定文件夹中
* @param str 需要生成二维码的字符串
* @param pathname 存放二维码图片的路径(路径中包含生成二维码图片的名称及图片格式)
* @param width 二维码图片的宽度
* @param height 二维码图片的高度
* @return 成功返回true 失败返回false  
*/
public static boolean foundToImage(String str,String pathname,int width,int height){

try {

//二维码的图片格式
String format = getImageFormat(pathname);
Map<EncodeHintType,Object> hints = new Hashtable<>();
//内容所使用编码
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
hints.put(EncodeHintType.MARGIN,1);
BitMatrix bitMatrix = new MultiFormatWriter().encode(str,BarcodeFormat.QR_CODE, width, height, hints);
//生成二维码
File outputFile = new File(pathname);
writeToFile(bitMatrix, format, outputFile);

return true;

} catch (Exception e) {
e.printStackTrace();
return false;
}

}

public static void main(String[] args){
String urlstr = "http://192.168.1.147:8090";
String pathname = "E:"+File.separator+"erweima.jpg";
System.out.println(foundToImage(urlstr, pathname, 300, 300));
}

60F40508-3411-4A16-8EF7-CBC7C6D0E659 From:https://www.cnblogs.com/xuejianxiyang/p/9143541.html