Java验证码图片生成

来源：互联网发布：寺院设计效果图软件编辑：程序博客网时间：2024/06/10 14:50
Servlet类如下：
/* * 日期：2017-02-18 * 作者： * 功能：生成一个验证码图片 * */package com.fox.hello;import java.awt.BasicStroke;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.geom.AffineTransform;import java.awt.geom.Line2D;import java.awt.image.BufferedImage;import java.io.IOException;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 IdentityServlet */@WebServlet(description = "生成验证码", urlPatterns = { "/IdentityServlet" })public class IdentityServlet extends HttpServlet {private static final long serialVersionUID = 1L;    /*该方法主要作用是获得随机生成的颜色*/       public Color getRandColor(int s,int e){          Random random=new Random ();          if(s>255) s=255;          if(e>255) e=255;          int r,g,b;          r=s+random.nextInt(e-s);    //随机生成RGB颜色中的r值          g=s+random.nextInt(e-s);    //随机生成RGB颜色中的g值          b=s+random.nextInt(e-s);    //随机生成RGB颜色中的b值          return new Color(r,g,b);      }    /**     * @see HttpServlet#HttpServlet()     */    public IdentityServlet() {        super();        // TODO Auto-generated constructor stub    }/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//设置不缓存图片          response.setHeader("Pragma", "No-cache");          response.setHeader("Cache-Control", "No-cache");          response.setDateHeader("Expires", 0);          //指定生成的响应图片,一定不能缺少这句话,否则错误.          response.setContentType("image/jpeg");          int width=100,height=30;     //指定生成验证码的宽度和高度          BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); //创建BufferedImage对象,其作用相当于一图片          Graphics g=image.getGraphics();     //创建Graphics对象,其作用相当于画笔          Graphics2D g2d=(Graphics2D)g;       //创建Grapchics2D对象          Random random=new Random();          Font mfont=new Font("楷体",Font.BOLD,16); //定义字体样式          g.setColor(getRandColor(200,250));          g.fillRect(0, 0, width, height);    //绘制背景          g.setFont(mfont);                   //设置字体          g.setColor(getRandColor(180,200));                    //绘制100条颜色和位置全部为随机产生的线条,该线条为2f          for(int i=0;i<100;i++){              int x=random.nextInt(width-1);              int y=random.nextInt(height-1);              int x1=random.nextInt(6)+1;              int y1=random.nextInt(12)+1;              BasicStroke bs=new BasicStroke(2f,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL); //定制线条样式              Line2D line=new Line2D.Double(x,y,x+x1,y+y1);              g2d.setStroke(bs);              g2d.draw(line);     //绘制直线          }          //输出由英文，数字，和中文随机组成的验证文字，具体的组合方式根据生成随机数确定。          String sRand="";          String ctmp="";          int itmp=0;          //制定输出的验证码为四位          for(int i=0;i<4;i++){              switch(random.nextInt(3)){                  case 1:     //生成A-Z的字母                       itmp=random.nextInt(26)+65;                       ctmp=String.valueOf((char)itmp);                       break;                  case 2:     //生成汉字                       String[] rBase={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};                        //生成第一位区码                       int r1=random.nextInt(3)+11;                       String str_r1=rBase[r1];                       //生成第二位区码                       int r2;                       if(r1==13){                           r2=random.nextInt(7);                          }else{                           r2=random.nextInt(16);                       }                       String str_r2=rBase[r2];                       //生成第一位位码                       int r3=random.nextInt(6)+10;                       String str_r3=rBase[r3];                       //生成第二位位码                       int r4;                       if(r3==10){                           r4=random.nextInt(15)+1;                       }else if(r3==15){                           r4=random.nextInt(15);                       }else{                           r4=random.nextInt(16);                       }                       String str_r4=rBase[r4];                       //将生成的机内码转换为汉字                       byte[] bytes=new byte[2];                       //将生成的区码保存到字节数组的第一个元素中                       String str_12=str_r1+str_r2;                       int tempLow=Integer.parseInt(str_12, 16);                       bytes[0]=(byte) tempLow;                       //将生成的位码保存到字节数组的第二个元素中                       String str_34=str_r3+str_r4;                       int tempHigh=Integer.parseInt(str_34, 16);                       bytes[1]=(byte)tempHigh;                       ctmp=new String(bytes);                       break;                  default:                       itmp=random.nextInt(10)+48;                       ctmp=String.valueOf((char)itmp);                       break;              }              sRand+=ctmp;              Color color=new Color(20+random.nextInt(110),20+random.nextInt(110),random.nextInt(110));              g.setColor(color);              //将生成的随机数进行随机缩放并旋转制定角度 PS.建议不要对文字进行缩放与旋转,因为这样图片可能不正常显示              /*将文字旋转制定角度*/              Graphics2D g2d_word=(Graphics2D)g;              AffineTransform trans=new AffineTransform();              trans.rotate((45)*3.14/180,15*i+8,7);              /*缩放文字*/              float scaleSize=random.nextFloat()+0.8f;              if(scaleSize>1f) scaleSize=1f;              trans.scale(scaleSize, scaleSize);              g2d_word.setTransform(trans);              g.drawString(ctmp, 15*i+18, 14);          }          HttpSession session=request.getSession(true);          session.setAttribute("randCheckCode", sRand);          g.dispose();    //释放g所占用的系统资源          ImageIO.write(image,"JPEG",response.getOutputStream()); //输出图片  }/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stubdoGet(request, response);}}
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