图片把随机生成的验证码盖住了

Question

package servlet;

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 java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

@WebServlet( "/demo")
public class Servlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        int width =100;
        int height = 50;
        BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        g.setColor(Color.GREEN);
        g.fillRect(0,0,width,height);
        String str  = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz0123456789";
        Random ran = new Random();
        for (int i = 1; i <= 4; i++) {
            int index =ran.nextInt(str.length());
            char ch = str.charAt(index);
            g.drawString(ch+"",width/5*i,height/2);
        }


        ImageIO.write(image,"jpg",response.getOutputStream());
    }
}

Answer 1

不是被盖住了，你需要设置文字的颜色和位置
g.setColor(new Color(r,g,b));
然后设置一个对比度高点的颜色，把文字设置下一点