效果图如上,
package cn.gdin.captcha;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
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;
public class JcaptchaServlet extends HttpServlet {
Random random = new Random();
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
int height = 220; //图片高
int width = 220; //图片宽
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D) image.getGraphics();
String picPath= JcaptchaServlet.class.getClassLoader().getResource("../image/"+(random.nextInt(4)+1)+".jpg").getPath(); 读取本地图片,做背景图片
g.drawImage(ImageIO.read(new File(picPath)), 0, 20, width, height, null); //将背景图片从高度20开始
g.setColor(Color.white); //设置颜色
g.drawRect(0, 0, width-1, height-1); //画边框
g.setFont(new Font("宋体",Font.BOLD,20)); //设置字体
Integer x=null,y=null; //用于记录坐标