生成验证码的工具类：VerifyCodeUtils（有几种实现方式，放入流，保存文件等）
public class VerifyCodeUtils {
//使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
private static Random random = new Random();
/**
* 使用系统默认字符源生成验证码
* @param verifySize 验证码长度
* @return
*/
public static String generateVerifyCode(int verifySize){
return generateVerifyCode(verifySize, VERIFY_CODES);
}
/**
* 使用指定源生成验证码
* @param verifySize 验证码长度
* @param sources 验证码字符源
* @return
*/
public static String generateVerifyCode(int verifySize, String sources){
if(sources == null || sources.length() == 0){
sources = VERIFY_CODES;
}
int codesLen = sources.length();
Random rand = new Random(System.currentTimeMillis());
StringBuilder verifyCode = new StringBuilder(verifySize);
for(int i = 0; i < verifySize; i++){
verifyCode.append(sources.charAt(rand.nextInt(codesLen-1)));
}
return verifyCode.toString();
}
/**
* 生成随机验证码文件,并返回验证码值
* @param w
* @param h
* @param outputFile
* @param verifySize
* @return
* @throws IOException
*/
public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException{
String verifyCode = generateVerifyCode(verifySize);
outputImage(w, h, outputFile, verifyCode);
return verifyCode;
}
/**
* 输出随机验证码图片流,并返回验证码值
* @param w
* @param h
* @param os
* @param verifySize
* @return
* @throws IOException
*/
public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException{
String verifyCode = generateVerifyCode(verifySize);
outputImage(w, h, os, verifyCode);
return verifyCode;
}
/**
* 生成指定验证码图像文件
* @param w
* @param h
* @param outputFile
* @param code
* @throws IOException
*/
public static void outputImage(int w, int h, File outputFile, String code) throws IOException{
if(outputFile == null){
return;
}
File dir = outputFile.getParentFile();
if(!dir.exists()){
dir.mkdirs();
}
try{
outputFile.createNewFile();
FileOutputStream fos = new FileOutputStream(outputFile);
outputImage(w, h, fos, code);
fos.close();
} catch(IOException e){
throw e;
}
}
/**
* 输出指定验证码图片流
* @param w
* @param h
* @param os
* @param code
* @throws IOException
*/
public static void outputImage(int w, int h, OutputStream os,String code)throwsIOException{
int verifySize = code.length();
BufferedImage image =newBufferedImage(w, h,BufferedImage.TYPE_INT_RGB);
Random rand =newRandom();
Graphics2D g2 = image.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
Color[] colors =newColor[5];
Color[] colorSpaces =newColor[]{Color.WHITE,Color.CYAN,
Color.GRAY,Color.LIGHT_GRAY,Color.MAGENTA,Color.ORANGE,
Color.PINK,Color.YELLOW };
float[] fractions =newfloat[colors.length];
for(int i =0; i < colors.length; i++){
colors[i]= colorSpaces[rand.nextInt(colorSpaces.length)];
fractions[i]= rand.nextFloat();
}
Arrays.sort(fractions);
g2.setColor(Color.GRAY);// 设置边框色
g2.fillRect(0,0, w, h);
Color c = getRandColor(200,250);
g2.setColor(c);// 设置背景色
g2.fillRect(0,2, w, h-4);
//绘制干扰线
Random random =newRandom();
g2.setColor(getRandColor(160,200));// 设置线条的颜色
for(int i =0; i <20; i++){
int x = random.nextInt(w -1);
int y = random.nextInt(h -1);
int xl = random.nextInt(6)+1;
int yl = random.nextInt(12)+1;
g2.drawLine(x, y, x + xl +40, y + yl +20);
}
// 添加噪点
float yawpRate =0.05f;// 噪声率
int area =(int)(yawpRate * w * h);
for(int i =0; i < area; i++){
int x = random.nextInt(w);
int y = random.nextInt(h);
int rgb = getRandomIntColor();
image.setRGB(x, y, rgb);
}
shear(g2, w, h, c);// 使图片扭曲
g2.setColor(getRandColor(100,160));
int fontSize = h-4;
Font font =newFont("Algerian",Font.ITALIC, fontSize);
g2.setFont(font);
char[] chars = code.toCharArray();
for(int i =0; i < verifySize; i++){
AffineTransform affine =newAffineTransform();
affine.setToRotation(Math.PI /4* rand.nextDouble()*(rand.nextBoolean()?1:-1),(w / verifySize)* i + fontSize/2, h/2);
g2.setTransform(affine);
g2.drawChars(chars, i,1,((w-10)/ verifySize)* i +5, h/2+ fontSize/2-10);
}
g2.dispose();
ImageIO.write(image,"jpg", os);
}
privatestaticColor getRandColor(int fc,int bc){
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);
returnnewColor(r, g, b);
}
privatestaticint getRandomIntColor(){
int[] rgb = getRandomRgb();
int color =0;
for(int c : rgb){
color = color <<8;
color = color | c;
}
return color;
}
privatestaticint[] getRandomRgb(){
int[] rgb =newint[3];
for(int i =0; i <3; i++){
rgb[i]= random.nextInt(255);
}
return rgb;
}
privatestaticvoid shear(Graphics g,int w1,int h1,Color color){
shearX(g, w1, h1, color);
shearY(g, w1, h1, color);
}
privatestaticvoid shearX(Graphics g,int w1,int h1,Color color){
int period = random.nextInt(2);
boolean borderGap =true;
int frames =1;
int phase = random.nextInt(2);
for(int i =0; i < h1; i++){
double d =(double)(period >>1)
*Math.sin((double) i /(double) period
+(6.2831853071795862D*(double) phase)
/(double) frames);
g.copyArea(0, i, w1,1,(int) d,0);
if(borderGap){
g.setColor(color);
g.drawLine((int) d, i,0, i);
g.drawLine((int) d + w1, i, w1, i);
}
}
}
privatestaticvoid shearY(Graphics g,int w1,int h1,Color color){
int period = random.nextInt(40)+10;// 50;
boolean borderGap =true;
int frames =20;
int phase =7;
for(int i =0; i < w1; i++){
double d =(double)(period >>1)
*Math.sin((double) i /(double) period
+(6.2831853071795862D*(double) phase)
/(double) frames);
g.copyArea(i,0,1, h1,0,(int) d);
if(borderGap){
g.setColor(color);
g.drawLine(i,(int) d, i,0);
g.drawLine(i,(int) d + h1, i, h1);
}
}
}
publicstaticvoid main(String[] args)throwsIOException{
File dir =newFile("c:/verifies");
int w =200, h =80;
// for(int i = 0; i < 50; i++){
String verifyCode = generateVerifyCode(4);
File file =newFile(dir, verifyCode +".jpg");
outputImage(w, h, file, verifyCode);
// }
}
}
2.servlet：CaptchaServlet
public class CaptchaServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
response.setContentType("image/jpeg");
//(先生成字符串保存，然后在把字符串绘制到图画)
//生成随机字串
String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
//存入会话session
HttpSession session = request.getSession(true);
DoradoContext context = DoradoContext.getCurrent();
session.setAttribute("code", verifyCode.toLowerCase());
//生成图片
int w = 120, h = 30;
VerifyCodeUtils.outputImage(w, h, response.getOutputStream(), verifyCode);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
}
4.web.xml
<servlet-mapping> <servlet-name>doradoServlet</servlet-name> <url-pattern>/dorado/*</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>CaptchaServlet</servlet-name> <url-pattern>/servlet/CaptchaServlet</url-pattern> </servlet-mapping>
5.调用
<div class="input-append"> <input id="captcha" type="text" name="j_captcha" /> <div class="add-on"> <img id="captchaImage" src="servlet/CaptchaServlet" /> </div> </div>
时间： 2024-08-25 16:32:33