java springmvc實(shí)現(xiàn)驗(yàn)證碼功能

<form>
   <div id="login_tip">
   管理員登錄
   </div>
  <div><input type="text" id="user_code" name="user_code" class="username" placeholder="請(qǐng)輸入賬號(hào)"></div>
  <div><input type="password" id="user_account" name="user_account" class="pwd" placeholder="請(qǐng)輸入密碼"></div>    
   <div id="btn_area"> 
      <input type="text" id="VerificationCode" name="VerificationCode" placeholder="請(qǐng)輸入驗(yàn)證碼" class="verify">
      <a href="javascript:void(0);" rel="external nofollow" onclick="VerificationCode()">
       <img id="randCodeImage" alt="驗(yàn)證碼" src="VerificationCode/generate.action" width="100" height="40"/>
      </a>
     </div>
     <div >
      <input type="button" name="button" id="sub_btn" onclick="login()" value="登錄"/>
     </div>
     <div id="verification_Code"><b></b></div>
</form>

<script type="text/javascript"> 
 function login(){
  //這是使用ajax的方式提交
  $.ajax({
   type:'post',
   url:'Uase/query.action',
   //data:$('#loginInputForm').serialize(),
   data:{
     'user_code' : $("#user_code").val(),
     'user_account' :$("#user_account").val(),
     'VerificationCode':$("#VerificationCode").val(),
   }, 
   dataType:'json',
   success:function(obj){
    var rad = Math.floor(Math.random() * Math.pow(10, 8));
    if(obj && obj.success=='true'){
     window.location.href='Uase/login.action';
    }else{
     document.getElementById("verification_Code"). innerHTML =obj.msg;
     //uuuy是隨便寫(xiě)的一個(gè)參數(shù)名稱(chēng)，后端不會(huì)做處理，作用是避免瀏覽器讀取緩存的鏈接
     $("#randCodeImage").attr("src", "VerificationCode/generate.action?uuuy="+rad);
     $("#VerificationCode").val("").focus(); // 清空并獲得焦點(diǎn)
    }
   }
  });
 }

  /**
  *驗(yàn)證碼刷新
  */
  function VerificationCode(){
   var rad = Math.floor(Math.random() * Math.pow(10, 8));
   //uuuy是隨便寫(xiě)的一個(gè)參數(shù)名稱(chēng)，后端不會(huì)做處理，作用是避免瀏覽器讀取緩存的鏈接
   $("#randCodeImage").attr("src", "VerificationCode/generate.action?uuuy="+rad);
  }

 </script>

@RequestMapping("/VerificationCode")
public class VerificationCodeController extends HttpServlet{
 private static final long serialVersionUID = 1L;

 /**
  * 這里用作存入session的名稱(chēng)
  */
 private static final String SESSION_KEY_OF_RAND_CODE = "randCode"; // todo 要統(tǒng)一常量

 /**
  * 
  */
 private static final int count = 200;

 /**
  * 定義圖形大小(寬)
  */
 private static final int width = 105;
 /**
  * 定義圖形大小(高)
  */
 private static final int height = 35;
 /**
  * 干擾線的長(zhǎng)度=1.414*lineWidth
  */
 private static final int lineWidth = 1;

 @RequestMapping(value = "/generate", method = { RequestMethod.POST,
   RequestMethod.GET })
 public void VerificationCode( HttpServletRequest request,
   HttpServletResponse response) throws ServletException,
   IOException {
   // 設(shè)置頁(yè)面不緩存
    response.setHeader("Pragma", "No-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.setDateHeader("Expires", 0);
    // response.setContentType("image/png");
    // 在內(nèi)存中創(chuàng)建圖象
    final BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    // 獲取圖形上下文
    final Graphics2D graphics = (Graphics2D) image.getGraphics();

    // 設(shè)定背景顏色
    graphics.setColor(Color.WHITE); // ---1.Color.WHITE為白色
    graphics.fillRect(0, 0, width, height);//填充衍射
    // 設(shè)定邊框顏色
    //graphics.setColor(getRandColor(100, 200)); // ---2.這是以數(shù)字型來(lái)設(shè)置顏色，顏色模式是指使用三種基色：紅、綠、藍(lán)，通過(guò)三種顏色的調(diào)整得出其它各種顏色，這三種基色的值范圍為0～255
    graphics.drawRect(0, 0, width - 1, height - 1);


    final Random random = new Random();
    // 隨機(jī)產(chǎn)生干擾線，使圖象中的認(rèn)證碼不易被其它程序探測(cè)到
    for (int i = 0; i < count; i++) {
     graphics.setColor(getRandColor(150, 200)); // ---3.

     final int x = random.nextInt(width - lineWidth - 1) + 1; // 保證畫(huà)在邊框之內(nèi)
     final int y = random.nextInt(height - lineWidth - 1) + 1;
     final int xl = random.nextInt(lineWidth);
     final int yl = random.nextInt(lineWidth);
     graphics.drawLine(x, y, x + xl, y + yl);
    }
    // 取隨機(jī)產(chǎn)生的認(rèn)證碼(4位數(shù)字)
    final String resultCode = exctractRandCode();
    for (int i = 0; i < resultCode.length(); i++) {
     // 將認(rèn)證碼顯示到圖象中,調(diào)用函數(shù)出來(lái)的顏色相同，可能是因?yàn)榉N子太接近，所以只能直接生成
     // graphics.setColor(new Color(20 + random.nextInt(130), 20 + random
     // .nextInt(130), 20 + random.nextInt(130)));

     // 設(shè)置字體顏色
     graphics.setColor(Color.BLACK);
     // 設(shè)置字體樣式
     //graphics.setFont(new Font("Arial Black", Font.ITALIC, 18));
     graphics.setFont(new Font("Times New Roman", Font.BOLD, 24));
     // 設(shè)置字符，字符間距，上邊距
     System.out.print(resultCode.charAt(i));
     graphics.drawString(String.valueOf(resultCode.charAt(i)), (23 * i) + 8, 26);
    }
    System.out.println("直接輸出："+resultCode);
    // 將認(rèn)證碼存入SESSION
    request.getSession().setAttribute(SESSION_KEY_OF_RAND_CODE, resultCode);
    // 圖象生效
    graphics.dispose();

    // 輸出圖象到頁(yè)面
    ImageIO.write(image, "JPEG", response.getOutputStream());   
 }


 /**
  * @return 隨機(jī)碼
  */
 private String exctractRandCode() {
  final String randCodeType = ResourceUtil.getRandCodeType();
  int randCodeLength = Integer.parseInt(ResourceUtil.getRandCodeLength());
  if (randCodeType == null) {
   return RandCodeImageEnum.NUMBER_CHAR.generateStr(randCodeLength);
  } else {
   switch (randCodeType.charAt(0)) {
   case '1':
    return RandCodeImageEnum.NUMBER_CHAR.generateStr(randCodeLength);
   case '2':
    return RandCodeImageEnum.LOWER_CHAR.generateStr(randCodeLength);
   case '3':
    return RandCodeImageEnum.UPPER_CHAR.generateStr(randCodeLength);
   case '4':
    return RandCodeImageEnum.LETTER_CHAR.generateStr(randCodeLength);
   case '5':
    return RandCodeImageEnum.ALL_CHAR.generateStr(randCodeLength);

   default:
    return RandCodeImageEnum.NUMBER_CHAR.generateStr(randCodeLength);
   }
  }
 }




 /**
  * 描述：根據(jù)給定的數(shù)字生成不同的顏色
  * @param 這是以數(shù)字型來(lái)設(shè)置顏色，顏色模式是指使用三種基色：紅、綠、藍(lán)，通過(guò)三種顏色的調(diào)整得出其它各種顏色，這三種基色的值范圍為0～255
  * @param 這是以數(shù)字型來(lái)設(shè)置顏色，顏色模式是指使用三種基色：紅、綠、藍(lán)，通過(guò)三種顏色的調(diào)整得出其它各種顏色，這三種基色的值范圍為0～255
  * @return 描述：返回顏色
  */
 private Color getRandColor(int fc, int bc) { // 取得給定范圍隨機(jī)顏色
  final Random random = new Random();
  if (fc > 255) {
   fc = 255;
  }
  if (bc > 255) {
   bc = 255;
  }

  final int r = fc + random.nextInt(bc - fc);
  final int g = fc + random.nextInt(bc - fc);
  final int b = fc + random.nextInt(bc - fc);

  return new Color(r, g, b);
 }



 /**
  * 驗(yàn)證碼輔助類(lèi)
  */
 enum RandCodeImageEnum {
  /**
   * 混合字符串
   */
  ALL_CHAR("0123456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), // 去除小寫(xiě)的l和o這個(gè)兩個(gè)不容易區(qū)分的字符；
  /**
   * 字符
   */
  LETTER_CHAR("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"),
  /**
   * 小寫(xiě)字母
   */
  LOWER_CHAR("abcdefghijklmnopqrstuvwxyz"),
  /**
   * 數(shù)字
   */
  NUMBER_CHAR("0123456789"),
  /**
   * 大寫(xiě)字符
   */
  UPPER_CHAR("ABCDEFGHIJKLMNOPQRSTUVWXYZ");
  /**
   * 待生成的字符串
   */
  private String charStr;

  /**
   * @param charStr
   */
  private RandCodeImageEnum(final String charStr) {
   this.charStr = charStr;
  }

  /**
   * 生產(chǎn)隨機(jī)驗(yàn)證碼
   * 
   * @param codeLength
   *   驗(yàn)證碼的長(zhǎng)度
   * @return 驗(yàn)證碼
   */
  public String generateStr(final int codeLength) {
   final StringBuffer sb = new StringBuffer();
   final Random random = new Random();
   final String sourseStr = getCharStr();

   for (int i = 0; i < codeLength; i++) {
    sb.append(sourseStr.charAt(random.nextInt(sourseStr.length())));
   }

   return sb.toString();
  }

  /**
   * @return the {@link #charStr}
   */
  public String getCharStr() {
   return charStr;
  }

 }
}

/**
 * 項(xiàng)目參數(shù)工具類(lèi)
 * 
 */
public class ResourceUtil {

 private static final ResourceBundle bundle = java.util.ResourceBundle.getBundle("sysConfig");
 /**
  * 獲取隨機(jī)碼的長(zhǎng)度
  *
  * @return 隨機(jī)碼的長(zhǎng)度
  */
 public static String getRandCodeLength() {
  return bundle.getString("randCodeLength");
 }

 /**
  * 獲取隨機(jī)碼的類(lèi)型
  *
  * @return 隨機(jī)碼的類(lèi)型
  */
 public static String getRandCodeType() {
  return bundle.getString("randCodeType");
 }

}

randCodeLength=4
randCodeType=5