导出图片压缩

wangqian
1 parent afc19d1b
Showing 1 changed file with 71 additions and 1 deletions
urbanops-module-garden/src/main/java/com/zteits/urbanops/module/garden/util/ImgDownUtils.java
@@ -4,6 +4,13 @@ import com.zteits.urbanops.module.infra.framework.file.core.client.FileClient;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.util.StringUtils;
+import javax.imageio.ImageIO;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -65,7 +72,10 @@ public class ImgDownUtils {
 				try {
 					String realPath = ImgDownUtils.getRealPath(url);
 					byte[] bytes = client.getContent(realPath);
-					result.add(bytes);
+					//result.add(bytes);
+					 // 核心：图片压缩，可自行调整参数
+					byte[] compressBytes = compressImage(bytes, 1600, 0, 0.65f);
+					result.add(compressBytes);
 				} catch (Exception e) {
 					log.error("[图片下载] 异常：{}，路径：{}", e.getMessage(), url);
 					result.add(null);
@@ -73,4 +83,64 @@ public class ImgDownUtils {
 			}
 		return result;
 	}
+
+	/**
+     * 图片压缩方法
+     * @param imageBytes 原始图片字节
+     * @param maxWidth 最大宽度，0不限制
+     * @param maxHeight 最大高度，0不限制
+     * @param quality jpg质量 0~1
+     * @return 压缩后byte[]
+     * @throws IOException
+     */
+    public static byte[] compressImage(byte[] imageBytes, int maxWidth, int maxHeight, float quality) throws IOException {
+        try (ByteArrayInputStream bis = new ByteArrayInputStream(imageBytes);
+             ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
+
+            BufferedImage srcImg = ImageIO.read(bis);
+            if (srcImg == null) {
+                throw new IOException("无法解析图片流");
+            }
+
+            int srcW = srcImg.getWidth();
+            int srcH = srcImg.getHeight();
+            int targetW = srcW;
+            int targetH = srcH;
+
+            // 等比例缩放
+            if (maxWidth > 0 && srcW > maxWidth) {
+                targetW = maxWidth;
+                targetH = (int) (srcH * ((double) targetW / srcW));
+            }
+            if (maxHeight > 0 && targetH > maxHeight) {
+                targetH = maxHeight;
+                targetW = (int) (srcW * ((double) targetH / srcH));
+            }
+
+            // 创建缩放画布
+            BufferedImage targetImg = new BufferedImage(targetW, targetH, BufferedImage.TYPE_3BYTE_BGR);
+            Graphics2D g2d = targetImg.createGraphics();
+            try {
+                g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+                g2d.drawImage(srcImg, 0, 0, targetW, targetH, null);
+            } finally {
+                g2d.dispose();
+            }
+
+            // JPG输出并设置质量
+            javax.imageio.IIOImage iioImage = new javax.imageio.IIOImage(targetImg, null, null);
+            javax.imageio.ImageWriteParam writeParam = javax.imageio.ImageIO.getImageWritersByFormatName("jpg").next().getDefaultWriteParam();
+            writeParam.setCompressionMode(javax.imageio.ImageWriteParam.MODE_EXPLICIT);
+            writeParam.setCompressionQuality(quality);
+
+            javax.imageio.ImageWriter writer = javax.imageio.ImageIO.getImageWritersByFormatName("jpg").next();
+            writer.setOutput(ImageIO.createImageOutputStream(bos));
+            try {
+                writer.write(null, iioImage, writeParam);
+            } finally {
+                writer.dispose();
+            }
+            return bos.toByteArray();
+        }
+    }
 }