servlet awt随机图片验证码

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剑握在手 2022-02-25 15:22:50 博主文章分类：Java技术积累 ©著作权

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package rd.test;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//输出一张图片
public class Test1 extends HttpServlet {

    public static final int WIDTH = 120;
    public static final int HEIGHT = 35;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);

        Graphics g = image.getGraphics();

        //1,设置背景色
        setBackGround(g);

        //2，设置边框
        setBorder(g);

        //3，画干扰线
        drowRandomLine(g);

        //4，写随机数
        //drawRandomNum(g);
<strong>String</strong> random = drawRandomNum2d((Graphics2D)g);//验证相关
　　　　　　　　　　request.getSession().setAttribute("checkcode",random);//验证相关      <br>        //5,图形写给浏览器
        response.setContentType("image/jpeg");
        //控制浏览器不要缓存随机验证码图片，让它每次都更新
        response.setDateHeader("expries", -1);
        response.setHeader("Cache-Control","no-cache");
        response.setHeader("Pragma","no-cache");
        ImageIO.write(image, "jpg", response.getOutputStream());
    }


    private void drowRandomLine(Graphics g) {
        // TODO Auto-generated method stub
        g.setColor(Color.GRAY);

        for(int i = 0;i<5;i++) {
int x1 = new Random().nextInt(WIDTH-2)+2;
int y1 = new Random().nextInt(HEIGHT-2)+2;

int x2 = new Random().nextInt(WIDTH-2)+2;
int y2 = new Random().nextInt(HEIGHT-2)+2;

g.drawLine(x1, y1, x2, y2);
}
}

private <strong>String</strong> drawRandomNum2d(Graphics2D g) {
        // TODO Auto-generated method stub
        g.setColor(Color.RED);
        g.setFont(new Font("宋体",Font.BOLD,20));
        //[\u4e00-\u9fa5]      
        String base = "一二三四五六七八九十百千万兆亿啊我饿依无余";

　　　　　　　　　　StringBuffer sb = new StringBuffer();//验证相关<br>       int x = 5;
        for(int i = 0;i<4;i++) {
int degree = new Random().nextInt()%30;
String ch = "" + base.charAt(new Random().nextInt(base.length()));
sb.append(ch);//验证相关<br>　　　　　　　　　　　　　  g.rotate(degree*Math.PI/180, x, 25);//设置旋转幅度
            g.drawString(ch, x, 25);
            g.rotate(-degree*Math.PI/180, x, 25);//转回去
            x+=30;
        }
<br>　　　　　　　　　　return sb.toString();
    }

    private void drawRandomNum(Graphics g) {
        g.setColor(Color.RED);
        g.setFont(new Font("宋体",Font.BOLD,20));
        //[\u4e00-\u9fa5]      
        String base = "一二三四五六七八九十百千万兆亿啊我饿依无余";

        int x = 5;
        for(int i = 0;i<4;i++) {
String ch = "" + base.charAt(new Random().nextInt(base.length()));
g.drawString(ch, x, 20);
x+=30;
}

}

private void setBorder(Graphics g) {
g.setColor(Color.BLUE);
g.drawRect(1, 1, WIDTH-2, HEIGHT-2);

}


private void setBackGround(Graphics g) {
// TODO Auto-generated method stub
g.setColor(Color.WHITE);
g.fillRect(0, 0, WIDTH, HEIGHT);
}


public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {


}

}