怎么用java代码把一个链接生成二维码

参考代码
import java.io.*;
import java.util.Date;
import java.awt.*;
import java.awt.image.*;
import javax.imageio.*;
public class QRCodeEncoderTest
{
/** Creates a new instance of QRCodeEncoderTest */
public QRCodeEncoderTest()
{
}
public static void create_image(String sms_info)throws Exception{
try{
qrcode testQrcode =new qrcode();
testQrcode.setQrcodeErrorCorrect('M');
testQrcode.setQrcodeEncodeMode('B');
testQrcode.setQrcodeVersion(7);
String testString = sms_info;
byte[] d = testString.getBytes("gbk");
System.out.println(d.length);
//BufferedImage bi = new BufferedImage(98, 98, BufferedImage.TYPE_INT_RGB);
BufferedImage bi = new BufferedImage(98, 98,