[JavaScript] Java实现Web页面前数字字母验证码实现

<ul>
   <li><label>验证码：</label></li>
   <li>
  <div>
  <input  type="text" name="validateCode"  class="login_input" value=""/>
  <img  id="img" src="${baseURL }/validateCode"  />
  </div>
  </li>
</ul>

<script type="text/javascript" language="javascript">
   
   //请求获取验证码
   function onclickValidateCode(obj){
   $(obj).attr("src","${baseURL }/validateCode?"+new Date().getTime());
   }
</script>

package com.njcc.pay.controller.login;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.p_w_picpath.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.p_w_picpathio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang3.math.NumberUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import com.alibaba.dubbo.common.utils.StringUtils;
/**
 * 验证马  Controller
 * 
 * @author Administrator
 *
 */
@Controller
public class ValidateCodeController {
@SuppressWarnings("unused")
private static final Log LOG = LogFactory.getLog(ValidateCodeController.class);
  public static final String VALIDATE_CODE = "validateCode";
private int w = 70;
private int h = 23;
/**
 * @throws Exception 
 * 函数功能说明 ： 进入后台登陆页面.
 * 
 * @参数： @return
 * @return String
 * @throws
 */
@RequestMapping(value = "/validateCode")
public void validateCode(HttpServletRequest request,
HttpServletResponse response) throws Exception {
createImage(request,response);
}

private void createImage(HttpServletRequest request,HttpServletResponse response) throws IOException {
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
response.setContentType("p_w_picpath/jpeg");
String width = request.getParameter("width");
String height = request.getParameter("height");
if (StringUtils.isNumeric(width) && StringUtils.isNumeric(height)) {
w = NumberUtils.toInt(width);
h = NumberUtils.toInt(height);
}
BufferedImage p_w_picpath = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics g = p_w_picpath.getGraphics();
/*
 * 生成背景
 */
createBackground(g);
/*
 * 生成字符
 */
String s = createCharacter(g);
request.getSession().setAttribute(VALIDATE_CODE, s);
g.dispose();
OutputStream out = response.getOutputStream();
ImageIO.write(p_w_picpath, "JPEG", out);
out.close();
}
/**
 * 生成颜色
 * @param fc
 * @param bc
 * @return
 */
private Color getRandColor(int fc,int bc) { 
int f = fc;
int b = bc;
Random random=new Random();
    if(f>255) {
    f=255; 
    }
    if(b>255) {
    b=255; 
    }
    return new Color(f+random.nextInt(b-f),f+random.nextInt(b-f),f+random.nextInt(b-f)); 
}
/**
 * 生成背景
 * @param g
 */
private void createBackground(Graphics g) {
// 填充背景
g.setColor(getRandColor(220,250)); 
g.fillRect(0, 0, w, h);
// 加入干扰线条
for (int i = 0; i < 8; i++) {
g.setColor(getRandColor(40,150));
Random random = new Random();
int x = random.nextInt(w);
int y = random.nextInt(h);
int x1 = random.nextInt(w);
int y1 = random.nextInt(h);
g.drawLine(x, y, x1, y1);
}
}
/**
 * 生成字符
 * @param g
 * @return
 */
private String createCharacter(Graphics g) {
char[] codeSeq = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J',
'K', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };
String[] fontTypes = {"Arial","Arial Black","AvantGarde Bk BT","Calibri"}; 
Random random = new Random();
StringBuilder s = new StringBuilder();
for (int i = 0; i < 4; i++) {
String r = String.valueOf(codeSeq[random.nextInt(codeSeq.length)]);//random.nextInt(10));
g.setColor(new Color(50 + random.nextInt(100), 50 + random.nextInt(100), 50 + random.nextInt(100)));
g.setFont(new Font(fontTypes[random.nextInt(fontTypes.length)],Font.BOLD,26)); 
g.drawString(r, 15 * i + 5, 19 + random.nextInt(8));
//g.drawString(r, i*w/4, h-5);
s.append(r);
}
return s.toString();
}


}