web实现图形验证功能

来源：互联网发布：java开发求职简历编辑：程序博客网时间：2024/06/06 08:42

这里直接上工程文件源码：

ValidateImage.java:

package jpeg;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.sun.image.codec.jpeg.JPEGCodec;import com.sun.image.codec.jpeg.JPEGEncodeParam;import com.sun.image.codec.jpeg.JPEGImageEncoder;public class ValidateImage extends HttpServlet {protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{    response.setContentType("image/jpeg");    createImage(response.getOutputStream());    response.setHeader("Pragma","No-cache");    response.setHeader("Cache-Control","no-cache");    response.setDateHeader("Expires", 0);}private void createImage(OutputStream out)throws IOException{int width=60, height=20;BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);Graphics g = image.getGraphics();Random random = new Random();g.setColor(getRandColor(200,250));g.fillRect(0, 0, width, height);g.setFont(new Font("Times New Roman",1,15));//g.setColor(new Color());//g.drawRect(0,0,width-1,height-1);g.setColor(getRandColor(160,200));for (int i=0;i<155;i++){int x = random.nextInt(width);int y = random.nextInt(height);        int xl = random.nextInt(12);        int yl = random.nextInt(12);g.drawLine(x,y,x+xl,y+yl);}//String rand = request.getParameter("rand");//rand = rand.substring(0,rand.indexOf("."));String sRand="";for (int i=0;i<4;i++){    String rand=String.valueOf(random.nextInt(10));    sRand+=rand;    g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));    g.drawString(rand,13*i+6,16);}              //session.setAttribute("rand",sRand);g.dispose();JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(image);param.setQuality(1.0f, false);encoder.setJPEGEncodeParam(param);try{encoder.encode(image);}catch (IOException ioe){ioe.printStackTrace();}}Color getRandColor(int fc,int bc){        Random random = new Random();        if(fc>255) fc=255;        if(bc>255) bc=255;        int r=fc+random.nextInt(bc-fc);        int g=fc+random.nextInt(bc-fc);        int b=fc+random.nextInt(bc-fc);        return new Color(r,g,b);        }}

TestImage.jsp:

  <body>    <img src="validate"> <br>  </body>

web.xml:

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">  <servlet>    <description>This is the description of my J2EE component</description>    <display-name>This is the display name of my J2EE component</display-name>    <servlet-name>ValidateImage</servlet-name>    <servlet-class>jpeg.ValidateImage</servlet-class>  </servlet>  <servlet-mapping>    <servlet-name>ValidateImage</servlet-name>    <url-pattern>/validate</url-pattern>  </servlet-mapping>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list></web-app>

地址栏：http://localhost:8080/JPEG/jsp/TestImage.jsp 结果：