1、 在action中书写获取验证码的方法
需要注意的是,要将验证码存入session ,切记return null
//验证码
public String execute()throws Exception{
//生成验证码
String code = SecurityCode.getSecurityCode();
ServletActionContext.getRequest().getSession().setAttribute(“code”,code);
//生成图片
BufferedImage image = SecurityImage.createImage(code);
//将验证码图片输出到浏览器
HttpServletResponse res = ServletActionContext.getResponse();
OutputStream out = res.getOutputStream();
ImageIO.write(image,“png”,out);
return null;
}
2、 配置struts文件
3、 配置jsp页面
需要使用img标签接收 ,更换点击超链接 设置单击事件,
在页面javascript 标签内书写function函数
package util; import java.util.Arrays; /** * * @author others * date:2021-3-26 下午2:17:19 * 描述:随机生成验证码值:验证码串 */ public class SecurityCode { /** * 验证码难度级别 * Simple-数字 * Medium-数字和小写字母 * Hard-数字和大小写字母 */ public enum SecurityCodeLevel { Simple, Medium, Hard }; /** * 产生默认验证码,4位中等难度 * * @return */ public static String getSecurityCode() { return getSecurityCode(4, SecurityCodeLevel.Medium, false); } /** * 产生长度和难度任意的验证码 * * @param length * @param level * @param isCanRepeat * @return */ private static String getSecurityCode(int length, SecurityCodeLevel level, boolean isCanRepeat) { // 随机抽取len个字符 int len = length; // 字符集合(--除去易混淆的数字0,1,字母l,o,O) char[] codes = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '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', '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' }; // 根据不同难度截取字符串 if (level == SecurityCodeLevel.Simple) { codes = Arrays.copyOfRange(codes, 0, 10); } else if (level == SecurityCodeLevel.Medium) { codes = Arrays.copyOfRange(codes, 0, 36); } // 字符集和长度 int n = codes.length; // 抛出运行时异常 if (len > n && isCanRepeat == false) { throw new RuntimeException(String.format("调用SecurityCode.getSecurityCode(%1$s,%2$s,%3$s)出现异常" + "当isCanRepeatΪ%3$s时,传入参数%1$s不能大于ܴ4$s", len, level, isCanRepeat, n)); } // 存放抽取出来的字符 char[] result = new char[len]; // 判断能否出现重复字符 if (isCanRepeat) { for (int i = 0; i < result.length; i++) { // 索引0 and n-1 int r = (int) (Math.random() * n); // 将result中的第i个元素设置为code[r]存放的数值ֵ result[i] = codes[r]; } } else { for (int i = 0; i < result.length; i++) { // 索引0 and n-1 int r = (int) (Math.random() * n); // 将result中的第i个元素设置为code[r]存放的数值ֵ result[i] = codes[r]; // 必须确保不会再次抽取到那个字符,这里用数组中最后一个字符改写code[r],并将n-1 codes[r] = codes[n - 1]; n--; } } return String.valueOf(result); } public static void main(String[] args) { System.out.println(SecurityCode.getSecurityCode()); } }
SecurityImage.java
package util; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.util.Random; import com.sun.image.codec.jpeg.*; public class SecurityImage { /** * 生成验证码图片 * @param securityCode * @return */ public static BufferedImage createImage(String securityCode){ int codeLength = securityCode.length();//验证码长度 int fontSize = 15;///字体大小 int fontWidth = fontSize+1; //图片宽高 int width = codeLength*fontWidth+6; int height = fontSize*2+1; //图片 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.setColor(Color.WHITE);//设置背景色 g.fillRect(0, 0, width, height);//填充背景 g.setColor(Color.LIGHT_GRAY);//设置边框颜色 g.setFont(new Font("Arial", Font.BOLD, height-2));//边框字体样式 g.drawRect(0, 0, width-1, height-1);//绘制边框 //绘制噪点 Random rand = new Random(); g.setColor(Color.LIGHT_GRAY); for (int i = 0; i < codeLength*6; i++) { int x = rand.nextInt(width); int y = rand.nextInt(height); g.drawRect(x, y, 1, 1);//绘制1*1大小的矩形 } //绘制验证码 int codeY = height-10; g.setColor(new Color(19,148,246)); g.setFont(new Font("Georgia", Font.BOLD, fontSize)); for(int i=0;i<codeLength;i++){ double deg=new Random().nextDouble()*20; g.rotate(Math.toRadians(deg), i*16+13,codeY-7.5); g.drawString(String.valueOf(securityCode.charAt(i)), i*16+5, codeY); g.rotate(Math.toRadians(-deg), i*16+13,codeY-7.5); } g.dispose();//关闭资源 return image; } /** * 返回验证码图片的流格式 * @param securityCode * @return */ private static ByteArrayInputStream getImageAsInputStream(String securityCode){ BufferedImage image = createImage(securityCode); return convertImageToStream(image); } /** * 将BufferedImage转换成ByteArrayinputStream * @param image * @return */ private static ByteArrayInputStream convertImageToStream(BufferedImage image){ ByteArrayInputStream inputStream = null; ByteArrayOutputStream outStream = new ByteArrayOutputStream(); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(outStream); try { encoder.encode(image); byte[] b = outStream.toByteArray(); inputStream = new ByteArrayInputStream(b); } catch (Exception e) { e.printStackTrace(); } return inputStream; } }