U 解决 背景图为 png 设置指定转换类型为 jpg 导致的图片变色问题

src/main/java/cloud/tianai/captcha/generator/AbstractImageCaptchaGenerator.java

@@ -10,6 +10,7 @@ import lombok.Setter;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
 
+import javax.imageio.ImageIO;
 import java.awt.image.BufferedImage;
 import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
@@ -66,9 +67,12 @@ public abstract class AbstractImageCaptchaGenerator implements ImageCaptchaGener
             return result;
         }
         ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
-        long currentTimeMillis = System.currentTimeMillis();
-        ImgWriter.write(bufferedImage, formatType, byteArrayOutputStream, -1);
-        System.out.println("耗时:" + (System.currentTimeMillis() - currentTimeMillis));
+        if (CaptchaImageUtils.isPng(formatType) || CaptchaImageUtils.isJpeg(formatType)) {
+            // 如果是 jpg 或者 png图片的话 用hutool的生成
+            ImgWriter.write(bufferedImage, formatType, byteArrayOutputStream, -1);
+        }else {
+            ImageIO.write(bufferedImage, formatType, byteArrayOutputStream);
+        }
         //转换成字节码
         byte[] data = byteArrayOutputStream.toByteArray();
         String base64 = Base64.getEncoder().encodeToString(data);

src/main/java/cloud/tianai/captcha/generator/common/util/CaptchaImageUtils.java

@@ -8,9 +8,7 @@ import java.awt.*;
 import java.awt.geom.Area;
 import java.awt.geom.CubicCurve2D;
 import java.awt.geom.QuadCurve2D;
-import java.awt.image.BufferedImage;
-import java.awt.image.PixelGrabber;
-import java.awt.image.RenderedImage;
+import java.awt.image.*;
 import java.io.InputStream;
 import java.net.URL;
 import java.util.ArrayList;
@@ -564,4 +562,5 @@ public class CaptchaImageUtils {
     public static boolean isPng(String type) {
         return TYPE_PNG.equalsIgnoreCase(type);
     }
+
 }