jquery实现无刷新验证码的简单实例_jquery

import java.awt.Color;  
import java.awt.Font;  
import java.awt.Graphics2D;  
import java.awt.image.BufferedImage;  
import java.util.Random;  
  
import javax.imageio.ImageIO;  
import javax.servlet.ServletException;  
import javax.servlet.ServletOutputStream;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import javax.servlet.http.HttpSession;  
  
public class https://img.gxlcms.com/verifyCodeServlet extends HttpServlet {  
  
  // 验证码图片的宽度。  
  private int width = 60;  
  
  // 验证码图片的高度。  
  private int height = 20;  
  
  // 验证码字符个数  
  private int codeCount = 4;  
  
  private int x = 0;  
  
  // 字体高度  
  private int fontHeight;  
  
  private int codeY;  
  
  char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',  
      'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',  
      'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };  
  
  /**  
   * 初始化验证图片属性  
   */  
  public void init() throws ServletException {  
    // 从web.xml中获取初始信息  
    // 宽度  
    String strWidth = this.getInitParameter("width");  
    // 高度  
    String strHeight = this.getInitParameter("height");  
    // 字符个数  
    String strCodeCount = this.getInitParameter("codeCount");  
  
    // 将配置的信息转换成数值  
    try {  
      if (strWidth != null && strWidth.length() != 0) {  
        width = Integer.parseInt(strWidth);  
      }  
      if (strHeight != null && strHeight.length() != 0) {  
        height = Integer.parseInt(strHeight);  
      }  
      if (strCodeCount != null && strCodeCount.length() != 0) {  
        codeCount = Integer.parseInt(strCodeCount);  
      }  
    } catch (NumberFormatException e) {  
    }  
  
    x = width / (codeCount + 1);  
    fontHeight = height - 2;  
    codeY = height - 4;  
  
  }  
  
  protected void service(HttpServletRequest req, HttpServletResponse resp)  
      throws ServletException, java.io.IOException {  
  
    // 定义图像buffer  
    BufferedImage buffImg = new BufferedImage(width, height,  
        BufferedImage.TYPE_INT_RGB);  
    Graphics2D g = buffImg.createGraphics();  
  
    // 创建一个随机数生成器类  
    Random random = new Random();  
  
    // 将图像填充为白色  
    g.setColor(Color.WHITE);  
    g.fillRect(0, 0, width, height);  
  
    // 创建字体，字体的大小应该根据图片的高度来定。  
    Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);  
    // 设置字体。  
    g.setFont(font);  
  
    // 画边框。  
    g.setColor(Color.BLACK);  
    g.drawRect(0, 0, width - 1, height - 1);  
  
    // 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到。  
    g.setColor(Color.BLACK);  
    for (int i = 0; i < 160; 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);  
    }  
  
    // randomCode用于保存随机产生的验证码，以便用户登录后进行验证。  
    StringBuffer randomCode = new StringBuffer();  
    int red = 0, green = 0, blue = 0;  
  
    // 随机产生codeCount数字的验证码。  
    for (int i = 0; i < codeCount; i++) {  
      // 得到随机产生的验证码数字。  
      String strRand = String.valueOf(codeSequence[random.nextInt(36)]);  
      // 产生随机的颜色分量来构造颜色值，这样

输出的每位数字的颜色值都将不同。 red = random.nextInt(255); green = random.nextInt(255); blue = random.nextInt(255); // 用随机产生的颜色将验证码绘制到图像中。 g.setColor(new Color(red, green, blue)); g.drawString(strRand, (i + 1) * x, codeY); // 将产生的四个随机数组合在一起。 randomCode.append(strRand); } // 将四位数字的验证码保存到Session中。 HttpSession session = req.getSession(); session.setAttribute("validateCode", randomCode.toString()); // 禁止图像缓存。 resp.setHeader("Pragma", "no-cache"); resp.setHeader("Cache-Control", "no-cache"); resp.setDateHeader("Expires", 0); resp.setContentType("image/jpeg"); // 将图像输出到Servlet输出流中。 ServletOutputStream sos = resp.getOutputStream(); ImageIO.write(buffImg, "jpeg", sos); sos.close(); } } import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class https://img.gxlcms.com/verifyCodeServlet extends HttpServlet { // 验证码图片的宽度。 private int width = 60; // 验证码图片的高度。 private int height = 20; // 验证码字符个数 private int codeCount = 4; private int x = 0; // 字体高度 private int fontHeight; private int codeY; char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' }; /** * 初始化验证图片属性 */ public void init() throws ServletException { // 从web.xml中获取初始信息 // 宽度 String strWidth = this.getInitParameter("width"); // 高度 String strHeight = this.getInitParameter("height"); // 字符个数 String strCodeCount = this.getInitParameter("codeCount"); // 将配置的信息转换成数值 try { if (strWidth != null && strWidth.length() != 0) { width = Integer.parseInt(strWidth); } if (strHeight != null && strHeight.length() != 0) { height = Integer.parseInt(strHeight); } if (strCodeCount != null && strCodeCount.length() != 0) { codeCount = Integer.parseInt(strCodeCount); } } catch (NumberFormatException e) { } x = width / (codeCount + 1); fontHeight = height - 2; codeY = height - 4; } protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { // 定义图像buffer BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = buffImg.createGraphics(); // 创建一个随机数生成器类 Random random = new Random(); // 将图像填充为白色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); // 创建字体，字体的大小应该根据图片的高度来定。 Font font = new Font("Fixedsys", Font.PLAIN, fontHeight); // 设置字体。 g.setFont(font); // 画边框。 g.setColor(Color.BLACK); g.drawRect(0, 0, width - 1, height - 1); // 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到。 g.setColor(Color.BLACK); for (int i = 0; i < 160; 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); } // randomCode用于保存随机产生的验证码，以便用户登录后进行验证。 StringBuffer randomCode = new StringBuffer(); int red = 0, green = 0, blue = 0; // 随机产生codeCount数字的验证码。 for (int i = 0; i < codeCount; i++) { // 得到随机产生的验证码数字。 String strRand = String.valueOf(codeSequence[random.nextInt(36)]); // 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。 red = random.nextInt(255); green = random.nextInt(255); blue = random.nextInt(255); // 用随机产生的颜色将验证码绘制到图像中。 g.setColor(new Color(red, green, blue)); g.drawString(strRand, (i + 1) * x, codeY); // 将产生的四个随机数组合在一起。 randomCode.append(strRand); } // 将四位数字的验证码保存到Session中。 HttpSession session = req.getSession(); session.setAttribute("validateCode", randomCode.toString()); // 禁止图像缓存。 resp.setHeader("Pragma", "no-cache"); resp.setHeader("Cache-Control", "no-cache"); resp.setDateHeader("Expires", 0); resp.setContentType("image/jpeg"); // 将图像输出到Servlet输出流中。 ServletOutputStream sos = resp.getOutputStream(); ImageIO.write(buffImg, "jpeg", sos); sos.close(); } }

import java.io.IOException;  
import java.io.PrintWriter;  
  
import javax.servlet.ServletException;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
  
public class ResultServlet extends HttpServlet {  
  
  /**  
   * The doGet method of the servlet. 
  
   *  
   * This method is called when a form has its tag value method equals to get.  
   *  
   * @param request the request send by the client to the server  
   * @param response the response send by the server to the client  
   * @throws ServletException if an error occurred  
   * @throws IOException if an error occurred  
   */  
  public void doGet(HttpServletRequest request, HttpServletResponse response)  
      throws ServletException, IOException {  
  
    doPost(request, response);  
  }  
  
  /**  
   * The doPost method of the servlet. 
  
   *  
   * This method is called when a form has its tag value method equals to post.  
   *  
   * @param request the request send by the client to the server  
   * @param response the response send by the server to the client  
   * @throws ServletException if an error occurred  
   * @throws IOException if an error occurred  
   */  
  public void doPost(HttpServletRequest request, HttpServletResponse response)  
      throws ServletException, IOException {  
  
    response.setContentType("text/html;charset=utf-8");  
    String validateC = (String) request.getSession().getAttribute("validateCode");  
    String veryCode = request.getParameter("c");  
    PrintWriter out = response.getWriter();  
    if(veryCode==null||"".equals(veryCode)){  
      out.println("验证码为空");  
    }else{  
      if(validateC.equals(veryCode)){  
        out.println("验证码正确");  
      }else{  
        out.println("验证码错误");  
      }  
    }  
    out.flush();  
    out.close();  
  }  
  
} 
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ResultServlet extends HttpServlet {

 /**
 * The doGet method of the servlet. 

 *
 * This method is called when a form has its tag value method equals to get.
 * 
 * @param request the request send by the client to the server
 * @param response the response send by the server to the client
 * @throws ServletException if an error occurred
 * @throws IOException if an error occurred
 */
 public void doGet(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

 doPost(request, response);
 }

 /**
 * The doPost method of the servlet. 

 *
 * This method is called when a form has its tag value method equals to post.
 * 
 * @param request the request send by the client to the server
 * @param response the response send by the server to the client
 * @throws ServletException if an error occurred
 * @throws IOException if an error occurred
 */
 public void doPost(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

 response.setContentType("text/html;charset=utf-8");
 String validateC = (String) request.getSession().getAttribute("validateCode");
 String veryCode = request.getParameter("c");
 PrintWriter out = response.getWriter();
 if(veryCode==null||"".equals(veryCode)){
  out.println("验证码为空");
 }else{
  if(validateC.equals(veryCode)){
  out.println("验证码正确");
  }else{
  out.println("验证码错误");
  }
 }
 out.flush();
 out.close();
 }

}

<%@ page language="java" contentType="text/html; charset=UTF-8"  
  pageEncoding="UTF-8"%>