//二维码内容
String text = "你好";  
int width = 100;  //宽
int height = 100;   //高
String format = "png";   //图片格式
Hashtable hints= new Hashtable();  
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");  
BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height,hints);  
//输出二维码目录
File outputFile = new File("F:/new.png");  
MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);