标签:class java实现验证码 横线 坐标 lin 矩形区域 protect 代码 throws
package com.baojuan.servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
* Servlet implementation class ValidCodeServlet
*/
@WebServlet("/ValidCode")
public class ValidCodeServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
//创建一张图片
//单位:像素
BufferedImage image=new BufferedImage(200, 100, BufferedImage.TYPE_INT_RGB);
ServletOutputStream os=res.getOutputStream();
//创建画板
//在画板上画东西之前必须要设置画笔
Graphics2D gra=image.createGraphics();
//设为白色
gra.setColor(Color.WHITE);
//从哪个坐标开始填充,后边两个为矩形区域
gra.fillRect(0, 0, 200, 100);
List<Integer> randList=new ArrayList<Integer>();
Random random=new Random();
for (int i = 0; i < 4; i++) {
randList.add(random.nextInt(10));
}
//设置字体为宋体,加粗斜体,字体大小为40px
gra.setFont(new Font("宋体", Font.ITALIC|Font.BOLD, 40));
//写字,设置字体颜色,随机变化
Color[] colors=new Color[] {Color.PINK,Color.BLACK,Color.BLUE,Color.GREEN,Color.YELLOW};
for (int i = 0; i < randList.size(); i++) {
gra.setColor(colors[random.nextInt(colors.length)]);
//设置字体,在一定范围内随机变化大小
gra.drawString(randList.get(i)+"", i*40, 70+(random.nextInt(21)-10));
}
//在画板上的数字上花两条横线,以防被人破解
for(int i=0;i<=1;i++) {
gra.setColor(colors[random.nextInt(colors.length)]);
//划横线
gra.drawLine(0, random.nextInt(101), 200, random.nextInt(101));
}
/*gra.setColor(colors[random.nextInt(colors.length)]);
//划横线
gra.drawLine(0, 50, 200, 50);*/
//工具类,加载图片
ImageIO.write(image, "jpg", os);
//把验证码放入session对象中,对登录功能验证是进行使用。
HttpSession session=req.getSession();
session.setAttribute("code", ""+randList.get(0)+randList.get(1)+randList.get(2)+randList.get(3));
}
}
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标签:class java实现验证码 横线 坐标 lin 矩形区域 protect 代码 throws
原文地址:https://www.cnblogs.com/aasu/p/10714356.html