java实现二维码生成的几个方法（推荐）

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.client.j2se.MatrixToImageWriter;  
import com.google.zxing.common.BitMatrix;  
import com.google.zxing.qrcode.QRCodeWriter;  
 
 
 
public class QRCodeEvents {  
    
  public static void main(String []args)throws Exception{  
    String text = "你好";  
    int width = 100;  
    int height = 100;  
    String format = "png";  
    Hashtable hints= new Hashtable();  
    hints.put(EncodeHintType.CHARACTER_SET, "utf-8");  
     BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height,hints);  
     File outputFile = new File("new.png");  
     MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);  
      
  }  
} 

text   : "https://github.com/jeromeetienne/jquery-qrcode" //设置二维码内容 

render  : "canvas",//设置渲染方式  
width    : 256,   //设置宽度  
height   : 256,   //设置高度  
typeNumber : -1,   //计算模式  
correctLevel  : QRErrorCorrectLevel.H,//纠错等级  
background   : "#ffffff",//背景颜色  
foreground   : "#000000" //前景颜色 

jQuery('#output').qrcode({width:200,height:200,correctLevel:0,text:content}); 

function utf16to8(str) {  
  var out, i, len, c;  
  out = "";  
  len = str.length;  
  for(i = 0; i < len; i++) {  
  c = str.charCodeAt(i);  
  if ((c >= 0x0001) && (c <= 0x007F)) {  
    out += str.charAt(i);  
  } else if (c > 0x07FF) {  
    out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));  
    out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));  
    out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));  
  } else {  
    out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));  
    out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));  
  }  
  }  
  return out;  
}