BufferedImage图片验证码

package com.servlet02.servlet;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
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;

/**
 * 获取随机验证码图像
 * 
 * @author Administrator
 *
 */
@WebServlet(value = "/getCodes02")
public class CodesServelt02 extends HttpServlet {

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		response.setContentType("image/jpeg");
		// 1.创建验证码图像(宽,高,类型)
		BufferedImage image = new BufferedImage(160, 50, BufferedImage.TYPE_3BYTE_BGR);
		// 2.在该图像上获取画笔
		Graphics g = image.getGraphics();
		// 设置图像背景色和前景色
		g.setColor(Color.WHITE);//设置笔刷白色
		g.fillRect(1,1,158,48);//填充整个屏幕 (x,y,w,h)
		g.setColor(Color.BLACK); //设置笔刷 
		// 字体
		Font font = new Font("华文琥珀", Font.ITALIC , 24);
		g.setFont(font);
		// x轴坐标
		int x = 20;
		for (int i = 1; i <= 6; i++) {
			// 3.获取验证码
			String code = getCode();
			// 4.利用画笔向图像中写随机验证码(验证码,x轴,y轴)
			g.drawString(code, x, 30);
			x += 20;
		}
		// 5.释放画笔资源
		g.dispose();
		// 6. 将图像输出给客户端
		ImageIO.write(image, "JPEG", response.getOutputStream());
	}

	/**
	 * 获取随机验证码
	 * 
	 * @return
	 */
	protected String getCode() {
		// 要返回的随机验证码(一位)
		String code = "";
		// 验证码库
		String codes = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		// 验证码库的长度
		int len = codes.length();
		// 获取随机对象
		Random random = new Random();
		// 随机验证码
		// 获取随机索引
		int index = random.nextInt(len);
		// 根据索引获取随机字符
		char ch = codes.charAt(index);
		code = String.valueOf(ch);
		return code;
	}
}

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