Upload 3493 files

08aee07 verified over 2 years ago

2.42 kB

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;

/**
 * 生成验证码
 */
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
		
		//服务器通知浏览器不要缓存
		response.setHeader("pragma","no-cache");
		response.setHeader("cache-control","no-cache");
		response.setHeader("expires","0");
		
		//在内存中创建一个长80，宽30的图片，默认黑色背景
		//参数一：长
		//参数二：宽
		//参数三：颜色
		int width = 80;
		int height = 30;
		BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
		
		//获取画笔
		Graphics g = image.getGraphics();
		//设置画笔颜色为灰色
		g.setColor(Color.GRAY);
		//填充图片
		g.fillRect(0,0, width,height);
		
		//产生4个随机验证码，12Ey
		String checkCode = getCheckCode();
		//将验证码放入HttpSession中
		request.getSession().setAttribute("CHECKCODE_SERVER",checkCode);
		
		//设置画笔颜色为黄色
		g.setColor(Color.YELLOW);
		//设置字体的小大
		g.setFont(new Font("黑体",Font.BOLD,24));
		//向图片上写入验证码
		g.drawString(checkCode,15,25);
		
		//将内存中的图片输出到浏览器
		//参数一：图片对象
		//参数二：图片的格式，如PNG,JPG,GIF
		//参数三：图片输出到哪里去
		ImageIO.write(image,"PNG",response.getOutputStream());
	}
	/**
	 * 产生4位随机字符串 
	 */
	private String getCheckCode() {
		String base = "0123456789ABCDEFGabcdefg";
		int size = base.length();
		Random r = new Random();
		StringBuffer sb = new StringBuffer();
		for(int i=1;i<=4;i++){
			//产生0到size-1的随机值
			int index = r.nextInt(size);
			//在base字符串中获取下标为index的字符
			char c = base.charAt(index);
			//将c放入到StringBuffer中去
			sb.append(c);
		}
		return sb.toString();
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		this.doGet(request,response);
	}
}

	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;

	/**
	* 生成验证码
	*/
	@WebServlet("/checkCodeServlet")
	public class CheckCodeServlet extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {

	//服务器通知浏览器不要缓存
	response.setHeader("pragma","no-cache");
	response.setHeader("cache-control","no-cache");
	response.setHeader("expires","0");

	//在内存中创建一个长80，宽30的图片，默认黑色背景
	//参数一：长
	//参数二：宽
	//参数三：颜色
	int width = 80;
	int height = 30;
	BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);

	//获取画笔
	Graphics g = image.getGraphics();
	//设置画笔颜色为灰色
	g.setColor(Color.GRAY);
	//填充图片
	g.fillRect(0,0, width,height);

	//产生4个随机验证码，12Ey
	String checkCode = getCheckCode();
	//将验证码放入HttpSession中
	request.getSession().setAttribute("CHECKCODE_SERVER",checkCode);

	//设置画笔颜色为黄色
	g.setColor(Color.YELLOW);
	//设置字体的小大
	g.setFont(new Font("黑体",Font.BOLD,24));
	//向图片上写入验证码
	g.drawString(checkCode,15,25);

	//将内存中的图片输出到浏览器
	//参数一：图片对象
	//参数二：图片的格式，如PNG,JPG,GIF
	//参数三：图片输出到哪里去
	ImageIO.write(image,"PNG",response.getOutputStream());
	}
	/**
	* 产生4位随机字符串
	*/
	private String getCheckCode() {
	String base = "0123456789ABCDEFGabcdefg";
	int size = base.length();
	Random r = new Random();
	StringBuffer sb = new StringBuffer();
	for(int i=1;i<=4;i++){
	//产生0到size-1的随机值
	int index = r.nextInt(size);
	//在base字符串中获取下标为index的字符
	char c = base.charAt(index);
	//将c放入到StringBuffer中去
	sb.append(c);
	}
	return sb.toString();
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	this.doGet(request,response);
	}
	}