From 4e91931b9ee2ade1593e9e21ca714220847e9ace Mon Sep 17 00:00:00 2001
From: wenc000 <450292408@qq.com>
Date: Fri, 27 Nov 2020 12:30:58 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E5=9B=BE=E7=89=87=E7=BC=93?=
 =?UTF-8?q?=E5=AD=98?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../service/file/impl/FileServiceImpl.java     | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/cloud-common-plugin/src/main/java/com/cm/common/plugin/service/file/impl/FileServiceImpl.java b/cloud-common-plugin/src/main/java/com/cm/common/plugin/service/file/impl/FileServiceImpl.java
index 32d33ce..3f3ac3c 100644
--- a/cloud-common-plugin/src/main/java/com/cm/common/plugin/service/file/impl/FileServiceImpl.java
+++ b/cloud-common-plugin/src/main/java/com/cm/common/plugin/service/file/impl/FileServiceImpl.java
@@ -15,7 +15,6 @@ import com.cm.common.plugin.service.file.IFileService;
 import com.cm.common.pojo.ListPage;
 import com.cm.common.pojo.dtos.FileDTO;
 import com.cm.common.pojo.pos.FilePO;
-import com.cm.common.result.SuccessResult;
 import com.cm.common.result.SuccessResultData;
 import com.cm.common.result.SuccessResultList;
 import com.cm.common.utils.DateUtil;
@@ -30,10 +29,11 @@ import net.coobird.thumbnailator.Thumbnails;
 import org.apache.catalina.connector.ClientAbortException;
 import org.apache.commons.fileupload.disk.DiskFileItem;
 import org.apache.commons.lang3.StringUtils;
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.security.core.parameters.P;
 import org.springframework.stereotype.Service;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.multipart.commons.CommonsMultipartFile;
@@ -343,6 +343,20 @@ public class FileServiceImpl extends AbstractService implements IFileService {
                 response.setHeader("Content-Disposition", "attachment;fileName=" + URLEncoder.encode(filePO.getFileName(), "UTF-8"));
             } else {
                 response.setHeader("Content-Disposition", "inline;fileName=" + URLEncoder.encode(filePO.getFileName(), "UTF-8"));
+                // 如果是图片资源，开启缓存
+                if (isImageFile(filePO.getFileType())) {
+                    // 如果存在校验修改时间且未做修改，返回304，使用本地资源
+                    String ifModifiedSince = request.getHeader("If-Modified-Since");
+                    if (StringUtils.isNotBlank(ifModifiedSince) && StringUtils.equalsIgnoreCase(ifModifiedSince, filePO.getGmtModified())) {
+                        response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
+                        return;
+                    }
+                    // 缓存有效时间为7天
+                    response.setHeader("Expires", DateTime.now().plusDays(7).toDateTime(DateTimeZone.forID("GMT")).toString());
+                    // 60秒之内不发送新请求
+                    response.setHeader("max-age", "60");
+                    response.setHeader("Last-Modified", filePO.getGmtModified());
+                }
             }
             String rangeString = null;
             if (canRange && request != null) {