这是代码上个问题的代码

<%@ page contentType="text/html;charset=UTF-8" language="java"
pageEncoding="UTF-8" %>

生成二维码

---

输入文本： 这是jsp

这是servlet
package a02a;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.swetake.util.Qrcode;

/**

• Servlet implementation class a02a_zhao
• /
  @WebServlet("/qrcode")
  public class a02a_zhao extends HttpServlet {
  private static final long serialVersionUID = 1L;
  /**
  • @see HttpServlet#HttpServlet
  • /
    public a02a_zhao() {
    super();
    }
    /**
  • @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
  • /
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
    //指定信息生成二维码，获取code
    String code = request.getParameter("code");
    Qrcode testQrcode = new Qrcode();
    //设置二维码的排错率，可选L(7%),M(15%),Q(25%),H(30%)
    //排错率越高能存储的信息越少，但对二维码的清晰度要求越高
    testQrcode.setQrcodeErrorCorrect('M');
    //设置编码模式，N为数字，A为英文字母，B为二进制，K为汉字
    testQrcode.setQrcodeEncodeMode('B');
    //设置二维码尺寸，范围为1到40，值越大，尺寸越大，信息越多
    testQrcode.setQrcodeVersion(7);
    byte[] d= code.getBytes(StandardCharsets.UTF_8);
    BufferedImage image = new BufferedImage(100,100,BufferedImage.TYPE_BYTE_BINARY);
    Graphics2D g = image.createGraphics();
    g.setBackground(Color.white);
    g.clearRect(0,0,100,100);
    g.setColor(Color.BLACK);
    if (d.length > 0 && d.length < 120)
    {

      boolean[][] s = testQrcode.calQrcode(d);
      for (int i = 0; i < s.length; i++){
          for (int j = 0; j < s.length; j++){
              if(s[j][i])
              {
                  g.fillRect(j*2+3,i*2+3,2,2);
              }
          }
      }
       g.dispose();
      image.flush();
      ImageIO.write(image,"jpg",response.getOutputStream());
    

    }

}

}
总是报404

404是什么你知道吗，你知道就能解决问题了