新增getContentType默认值；解决IE浏览器验证码不显示

src/main/java/com/wf/captcha/ArithmeticCaptcha.java

@@ -50,6 +50,11 @@ public class ArithmeticCaptcha extends ArithmeticCaptchaAbstract {
         return toBase64("data:image/png;base64,");
     }
 
+    @Override
+    public String getContentType() {
+        return "image/png";
+    }
+
     /**
      * 生成验证码图形
      *
@@ -93,4 +98,4 @@ public class ArithmeticCaptcha extends ArithmeticCaptchaAbstract {
         }
         return false;
     }
-}
+}

src/main/java/com/wf/captcha/ChineseCaptcha.java

@@ -46,6 +46,11 @@ public class ChineseCaptcha extends ChineseCaptchaAbstract {
         return toBase64("data:image/png;base64,");
     }
 
+    @Override
+    public String getContentType() {
+        return "image/png";
+    }
+
     /**
      * 生成验证码图形
      *

src/main/java/com/wf/captcha/ChineseGifCaptcha.java

@@ -79,6 +79,11 @@ public class ChineseGifCaptcha extends ChineseCaptchaAbstract {
         return toBase64("data:image/gif;base64,");
     }
 
+    @Override
+    public String getContentType() {
+        return "image/gif";
+    }
+
     /**
      * 画随机码图
      *

src/main/java/com/wf/captcha/GifCaptcha.java

@@ -85,6 +85,11 @@ public class GifCaptcha extends Captcha {
         return toBase64("data:image/gif;base64,");
     }
 
+    @Override
+    public String getContentType() {
+        return "image/gif";
+    }
+
     /**
      * 画随机码图
      *

src/main/java/com/wf/captcha/SpecCaptcha.java

@@ -50,6 +50,11 @@ public class SpecCaptcha extends Captcha {
         return toBase64("data:image/png;base64,");
     }
 
+    @Override
+    public String getContentType() {
+        return "image/png";
+    }
+
     /**
      * 生成验证码图形
      *
@@ -96,4 +101,4 @@ public class SpecCaptcha extends Captcha {
         }
         return false;
     }
-}
+}

src/main/java/com/wf/captcha/base/Captcha.java

@@ -116,6 +116,13 @@ public abstract class Captcha extends Randoms {
      */
     public abstract String toBase64();
 
+    /**
+     * 获取图片歌手
+     *
+     * @return 图片格式 MINI
+     */
+    public abstract String getContentType();
+
     /**
      * 输出base64编码
      *
@@ -308,4 +315,4 @@ public abstract class Captcha extends Randoms {
     public void setCharType(int charType) {
         this.charType = charType;
     }
-}
+}

src/main/java/com/wf/captcha/utils/CaptchaUtil.java

@@ -117,6 +117,7 @@ public class CaptchaUtil {
      */
     public static void out(Captcha captcha, HttpServletRequest request, HttpServletResponse response)
             throws IOException {
+        response.setContentType(captcha.getContentType());
         setHeader(response);
         request.getSession().setAttribute(SESSION_KEY, captcha.text().toLowerCase());
         captcha.out(response.getOutputStream());
@@ -152,7 +153,6 @@ public class CaptchaUtil {
      * @param response HttpServletResponse
      */
     public static void setHeader(HttpServletResponse response) {
-        response.setContentType("image/gif");
         response.setHeader("Pragma", "No-cache");
         response.setHeader("Cache-Control", "no-cache");
         response.setDateHeader("Expires", 0);