一、引用所需的包
<dependencies>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.10</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.osgi</groupId>
<artifactId>org.osgi</artifactId>
<version>3.0.0</version>
<type>jar</type>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.7</version>
<type>jar</type>
</dependency>
</dependencies>
public class CodeUtil {
public static final String VERIFY_CODES = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
/**
* 使用系統默認字符源生成驗證碼
* @param verifySize 驗證碼長度
* @return
*/
public static String generateVerifyCode(int verifySize){
return generateVerifyCode(verifySize, VERIFY_CODES);
}
/**
* 使用指定源生成驗證碼
* @param verifySize 驗證碼長度
* @param sources 驗證碼字符源
* @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();
}
/**
* 生成隨機驗證碼文件,並返回驗證碼值
* @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;
}
/**
* 輸出隨機驗證碼圖片流,並返回驗證碼值
* @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;
}
/**
* 生成指定驗證碼圖像文件
* @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;
}
}
/**
* 輸出指定驗證碼圖片流
* @param w
* @param h
* @param os
* @param code
* @throws IOException
*/
public static void outputImage(int w,
int h,
OutputStream os,
String code) throws IOException{
int verifySize = code.length();
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Random rand = new Random();
Graphics2D g2 = image.createGraphics();
Color[] colors = new Color[5];
Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN,
Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
Color.PINK, Color.YELLOW };
float[] fractions = new float[colors.length];
for(int i = 0; i < colors.length; i++){
colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
fractions[i] = rand.nextFloat();
}
Arrays.sort(fractions);
Paint linearPaint = new LinearGradientPaint(0, 0, w, h, fractions, colors);
Paint linearPaint2 = new LinearGradientPaint(0, 0, w, h, new float[]{0.3f, .6f, .8f, .9f}, new Color[]{Color.BLUE, Color.BLACK, Color.GREEN, Color.BLUE});
//設置圖片背景爲白色
g2.setPaint(Color.WHITE);
g2.fillRect(0, 0, w, h);
//設置圖片漸變背景
g2.setPaint(linearPaint);
g2.fillRoundRect(0, 0, w, h, 5, 5);
g2.setPaint(linearPaint2);
int fontSize = (int) (Math.min(w/verifySize, h));
Font font = new Font("微軟雅黑", Font.BOLD, fontSize);
g2.setFont(font);
char[] chars = code.toCharArray();
for(int i = 0; i < verifySize; i++){
AffineTransform affine = new AffineTransform();
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 / verifySize) * i, h/2 + fontSize /2);
}
g2.dispose();
ImageIO.write(image, "jpg", os);
}
// public static void main(String[] args) throws IOException{
// File dir = new File("F:/verifies");
// int w = 200, h = 80;
// for(int i = 0; i < 100; i++){
// String verifyCode = generateVerifyCode(4);
// File file = new File(dir, verifyCode + ".jpg");
// outputImage(w, h, file, verifyCode);
// }
// }
}
三、調用
<div class="form-group">
<label for="verifyCode"><span class="form-require"></span>驗證碼:</label>
<div class="form-control-box">
<input class="form-control" type="text" id="verifyCode" value="" name="verifyCode">
<img id="vCode" src="/Image.do" />
<a href="javascript:changeCode();" class="login-forget primary"> 看不清,換一個</a>
</div>
</div>
public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
int w = 70, h = 40;
String validateCode=CodeUtil.generateVerifyCode(4);
request.getSession().setAttribute("validateCode", validateCode);//必須放在方法調用的前面
CodeUtil.outputImage(w,h,response.getOutputStream(),validateCode);
}
完畢!