java驗證碼功能

後台java代碼：

package net.cloudsun.base.controller; import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.PrintWriter;
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;
import net.cloudsun.base.service.CheckCodeService;
import net.cloudsun.base.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;


/**
 * @author 熊浪
 *
 */
@Controller
@RequestMapping(value = "/xuan")
public class VerifyCodeServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Autowired
private CheckCodeService checkCodeService;
@Autowired
private UserService userService;


// 驗證碼圖片的寬度。
private int width = 55;
// 驗證碼圖片的高度。
private int height = 30;
// 驗證碼字元個數
private int codeCount = 4;
private int x = 0;
// 字型高度
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' };
char[] codeSequence_tele = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
'9' };


/**
* 初始化驗證圖片屬性
*/
public void initxuan() throws ServletException {
// 從web.xml中擷取初始資訊
// 寬度
String strWidth = "70";
// 高度
String strHeight = "30";
// 字元個數
String strCodeCount = "4";
// 將配置的資訊轉換成數值
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;


}


@RequestMapping(value = "/verifyCode/{id}", method = RequestMethod.GET)
public @ResponseBody void service(@PathVariable("id") int id,
HttpServletRequest req, HttpServletResponse resp)
throws ServletException, java.io.IOException {
String type_tele = req.getParameter("type_tele");
initxuan();
// 定義映像buffer
BufferedImage buffImg = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
Graphics2D g = buffImg.createGraphics();
// 建立一個隨機數產生器類
Random random = new Random();
// 將映像填充為白色
g.setColor(new Color(255, 193, 37));
g.fillRect(0, 0, width, height);
// 建立字型，字型的大小應該根據圖片的高度來定。
Font font = new Font("Fixedsys", Font.BOLD, fontHeight);
// 設定字型。
g.setFont(font);
// 畫邊框。
g.setColor(Color.BLACK);
g.drawRect(0, 0, width - 1, height - 1);
// 隨機產生160條幹擾線，使圖象中的認證碼不易被其它程式探測到。
// g.setColor(Color.BLACK);
for (int i = 0; i < 10; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(5);
int yl = random.nextInt(5);
g.drawLine(x, y, x + xl, y + yl);
}
// randomCode用於儲存隨機產生的驗證碼，以便使用者登入後進行驗證。
StringBuffer randomCode = new StringBuffer();
int red = 0, green = 0, blue = 0;
// 隨機產生codeCount數位驗證碼。
for (int i = 0; i < codeCount; i++) {
// 得到隨機產生的驗證碼數字。
String strRand = " ";
if ('1' == type_tele.charAt(0)) {
strRand = String.valueOf(codeSequence[random.nextInt(30)]);
}
if ('2' == type_tele.charAt(0)) {
strRand = String.valueOf(codeSequence[random.nextInt(30)]);
}
// 產生隨機的顏色分量來構造顏色值，這樣輸出的每位元字的顏色值都將不同。
red = random.nextInt(255);
green = random.nextInt(255);
blue = random.nextInt(255);
// 用隨機產生的顏色將驗證碼繪製到映像中。
g.setColor(new Color(red, green, blue));
g.drawString(strRand, i * x, codeY);
// 將產生的四個隨機數組合在一起。
randomCode.append(strRand);
}
// 將四位元字的驗證碼儲存到Session中。
HttpSession session = req.getSession();
session.setAttribute("validateCode" + id, randomCode.toString());
// 禁止映像緩衝。
resp.setHeader("Pragma", "no-cache");
resp.setHeader("Cache-Control", "no-cache");
resp.setDateHeader("Expires", 0);
resp.setContentType("image/jpeg");
// 將映像輸出到Servlet輸出資料流中。
ServletOutputStream sos = resp.getOutputStream();
ImageIO.write(buffImg, "jpeg", sos);
sos.close();
}


@RequestMapping(value = "/valiCode", method = RequestMethod.POST)
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String id = request.getParameter("id");
String validateC = (String) request.getSession().getAttribute(
"validateCode" + id);//獲得儲存在session中的驗證碼
String veryCode = request.getParameter("c").toLowerCase();//獲得前台輸入的驗證碼
PrintWriter out = response.getWriter();
if (veryCode == null || "".equals(veryCode)) {
out.println("1");
} else {
if (validateC == null) {
out.println("3");
} else {
if (validateC.toLowerCase().equals(veryCode)) {
out.println("0");
} else {
out.println("2");
}
}
}
out.flush();
out.close();

}

}

前台jsp代碼：

<img src="/xuan/verifyCode/1?type_tele=1" width="51px;" id="imgObj" />js校正就不說了。

效果圖：