Servlet 中实现图片验证码功能
Servlet 中实现图片验证码功能
shuimo_123 发表于1年前
Servlet 中实现图片验证码功能
  • 发表于 1年前
  • 阅读 2
  • 收藏 0
  • 点赞 0
  • 评论 0

腾讯云 十分钟定制你的第一个小程序>>>   

摘要: 初学者,记录
package com.controller;

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

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ImageValidateGenerator extends HttpServlet {
	private static final long serialVersionUID = 1L;
          //图片上生成的内容
	private static final String str="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
	private Random random = new Random();//声明一个随机对象
	/**
	 * Constructor of the object.
	 */
	public ImageValidateGenerator() {
		super();
	}
	/**
	 * 生成随机的颜色
	 */
	private Color createRandColor(){
		int r=random.nextInt(256);
		int g=random.nextInt(256);
		int b=random.nextInt(256);
		
		return new Color(r,g,b);
	}
	/**
	 * 随机生成一个四位验证码
	 */
	private String createVerfiyCode(){
		StringBuilder code=new StringBuilder();
		for(int i=0;i<4;i++){
			
			char c=str.charAt(random.nextInt(str.length()));
			
			System.out.println(code.append(c)+"------------");
		}
		return code.toString();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doPost(request,response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//定义一个图像数据缓冲区
		BufferedImage myimage=new BufferedImage(100,50,BufferedImage.TYPE_INT_RGB);
		//在图片之上绘制图形
		Graphics mypen=myimage.getGraphics();
		mypen.setColor(Color.WHITE);//画笔的颜色
		mypen.fillRect(0, 0, 100, 50);
		for(int i=0;i<70;i++){
			
			mypen.setColor(createRandColor());//设置的随机颜色
			int x1=random.nextInt(80);
			int y1=random.nextInt(50);
			int x2=random.nextInt(30);//第二次起始位置去画线
			int y2=random.nextInt(30);
			
			mypen.drawLine(x1, y1, x2, y2);
			
		}
		mypen.setFont(new Font("微软雅黑",Font.BOLD,30));
		String validateCode=createVerfiyCode();
		request.getSession().setAttribute("validateCode",validateCode);
		
		for(int i=0;i<validateCode.length();i++){
			mypen.setColor(createRandColor());//设置颜色
			mypen.drawString(validateCode.charAt(i)+"",i*15+5,30);
			
		}
		ServletOutputStream sos=response.getOutputStream();
		ImageIO.write(myimage, "png", sos);
		sos.flush();
		sos.close();
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

 

共有 人打赏支持
粉丝 0
博文 2
码字总数 458
×
shuimo_123
如果觉得我的文章对您有用,请随意打赏。您的支持将鼓励我继续创作!
* 金额(元)
¥1 ¥5 ¥10 ¥20 其他金额
打赏人
留言
* 支付类型
微信扫码支付
打赏金额:
已支付成功
打赏金额: