diff --git a/src/main/java/run/halo/app/controller/admin/api/ThemeController.java b/src/main/java/run/halo/app/controller/admin/api/ThemeController.java
index 3cbd366f1..4734e1386 100644
--- a/src/main/java/run/halo/app/controller/admin/api/ThemeController.java
+++ b/src/main/java/run/halo/app/controller/admin/api/ThemeController.java
@@ -140,4 +140,9 @@ public class ThemeController {
     public void reload() {
         themeService.reload();
     }
+
+    @GetMapping(value = "activation/template/exists")
+    public BaseResponse exists(@RequestParam(value = "template") String template) {
+        return BaseResponse.ok(themeService.templateExists(template));
+    }
 }
diff --git a/src/main/java/run/halo/app/event/post/AbstractVisitEventListener.java b/src/main/java/run/halo/app/event/post/AbstractVisitEventListener.java
index 5af630d9d..1724e2b66 100644
--- a/src/main/java/run/halo/app/event/post/AbstractVisitEventListener.java
+++ b/src/main/java/run/halo/app/event/post/AbstractVisitEventListener.java
@@ -1,8 +1,8 @@
 package run.halo.app.event.post;
 
-import cn.hutool.core.lang.Assert;
 import lombok.NonNull;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.util.Assert;
 import run.halo.app.service.base.BasePostService;
 
 import java.util.Map;
diff --git a/src/main/java/run/halo/app/handler/file/AliYunFileHandler.java b/src/main/java/run/halo/app/handler/file/AliYunFileHandler.java
index 9dc1c6182..554499024 100644
--- a/src/main/java/run/halo/app/handler/file/AliYunFileHandler.java
+++ b/src/main/java/run/halo/app/handler/file/AliYunFileHandler.java
@@ -1,13 +1,14 @@
 package run.halo.app.handler.file;
 
-import cn.hutool.core.lang.Assert;
 import com.aliyun.oss.OSS;
 import com.aliyun.oss.OSSClientBuilder;
-import com.aliyun.oss.model.*;
+import com.aliyun.oss.model.DeleteObjectsRequest;
+import com.aliyun.oss.model.PutObjectResult;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.http.MediaType;
 import org.springframework.stereotype.Component;
+import org.springframework.util.Assert;
 import org.springframework.web.multipart.MultipartFile;
 import run.halo.app.exception.FileOperationException;
 import run.halo.app.model.enums.AttachmentType;
@@ -18,11 +19,11 @@ import run.halo.app.utils.FilenameUtils;
 
 import javax.imageio.ImageIO;
 import java.awt.image.BufferedImage;
-import java.util.Date;
 import java.util.Objects;
 
 /**
  * AliYun file handler.
+ *
  * @author MyFaith
  * @date 2019-04-04 00:06:13
  */
@@ -81,7 +82,7 @@ public class AliYunFileHandler implements FileHandler {
             }
 
             return uploadResult;
-        } catch (Exception e){
+        } catch (Exception e) {
             e.printStackTrace();
         } finally {
             ossClient.shutdown();
diff --git a/src/main/java/run/halo/app/security/handler/DefaultAuthenticationFailureHandler.java b/src/main/java/run/halo/app/security/handler/DefaultAuthenticationFailureHandler.java
index fa2aa4147..ada70d584 100644
--- a/src/main/java/run/halo/app/security/handler/DefaultAuthenticationFailureHandler.java
+++ b/src/main/java/run/halo/app/security/handler/DefaultAuthenticationFailureHandler.java
@@ -1,15 +1,14 @@
 package run.halo.app.security.handler;
 
-import run.halo.app.exception.HaloException;
-import run.halo.app.model.support.BaseResponse;
-import run.halo.app.utils.ExceptionUtils;
-import run.halo.app.utils.JsonUtils;
 import cn.hutool.extra.servlet.ServletUtil;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.http.MediaType;
 import org.springframework.util.Assert;
 import run.halo.app.exception.HaloException;
+import run.halo.app.model.support.BaseResponse;
+import run.halo.app.utils.ExceptionUtils;
+import run.halo.app.utils.JsonUtils;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
diff --git a/src/main/java/run/halo/app/service/impl/JournalCommentServiceImpl.java b/src/main/java/run/halo/app/service/impl/JournalCommentServiceImpl.java
index 40c580cac..5493b7968 100644
--- a/src/main/java/run/halo/app/service/impl/JournalCommentServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/JournalCommentServiceImpl.java
@@ -1,11 +1,11 @@
 package run.halo.app.service.impl;
 
 import cn.hutool.core.collection.CollectionUtil;
-import cn.hutool.core.lang.Assert;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.stereotype.Service;
+import org.springframework.util.Assert;
 import run.halo.app.exception.NotFoundException;
 import run.halo.app.model.dto.JournalDTO;
 import run.halo.app.model.entity.Journal;
diff --git a/src/main/java/run/halo/app/service/impl/RecoveryServiceImpl.java b/src/main/java/run/halo/app/service/impl/RecoveryServiceImpl.java
index 94ddb0248..6e4aaed99 100644
--- a/src/main/java/run/halo/app/service/impl/RecoveryServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/RecoveryServiceImpl.java
@@ -1,12 +1,12 @@
 package run.halo.app.service.impl;
 
-import cn.hutool.core.lang.Assert;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Service;
+import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.FileCopyUtils;
 import org.springframework.web.multipart.MultipartFile;
diff --git a/src/main/java/run/halo/app/service/impl/ThemeServiceImpl.java b/src/main/java/run/halo/app/service/impl/ThemeServiceImpl.java
index db20bd359..579ab2b4c 100644
--- a/src/main/java/run/halo/app/service/impl/ThemeServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/ThemeServiceImpl.java
@@ -1,6 +1,5 @@
 package run.halo.app.service.impl;
 
-import cn.hutool.core.io.FileUtil;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
 import org.eclipse.jgit.api.Git;
@@ -28,7 +27,6 @@ import run.halo.app.model.support.HaloConst;
 import run.halo.app.model.support.ThemeFile;
 import run.halo.app.service.OptionService;
 import run.halo.app.service.ThemeService;
-import run.halo.app.service.support.HaloMediaType;
 import run.halo.app.utils.FileUtils;
 import run.halo.app.utils.FilenameUtils;
 import run.halo.app.utils.HaloUtils;
@@ -248,7 +246,7 @@ public class ThemeServiceImpl implements ThemeService {
 
         try {
             // Delete the folder
-            FileUtil.del(Paths.get(themeProperty.getThemePath()));
+            FileUtils.del(Paths.get(themeProperty.getThemePath()));
 
             // Delete theme cache
             eventPublisher.publishEvent(new ThemeUpdatedEvent(this));
@@ -329,6 +327,16 @@ public class ThemeServiceImpl implements ThemeService {
         return activatedTheme;
     }
 
+    /**
+     * Sets activated theme.
+     *
+     * @param activatedTheme activated theme
+     */
+    private void setActivatedTheme(@Nullable ThemeProperty activatedTheme) {
+        this.activatedTheme = activatedTheme;
+        this.activatedThemeId = Optional.ofNullable(activatedTheme).map(ThemeProperty::getId).orElse(null);
+    }
+
     @Override
     public ThemeProperty activateTheme(String themeId) {
         // Check existence of the theme
@@ -513,16 +521,6 @@ public class ThemeServiceImpl implements ThemeService {
         return Files.createTempDirectory("halo");
     }
 
-    /**
-     * Sets activated theme.
-     *
-     * @param activatedTheme activated theme
-     */
-    private void setActivatedTheme(@Nullable ThemeProperty activatedTheme) {
-        this.activatedTheme = activatedTheme;
-        this.activatedThemeId = Optional.ofNullable(activatedTheme).map(ThemeProperty::getId).orElse(null);
-    }
-
     /**
      * Lists theme files as tree view.
      *
diff --git a/src/main/java/run/halo/app/utils/FileUtils.java b/src/main/java/run/halo/app/utils/FileUtils.java
index 30780f693..d7aac7685 100644
--- a/src/main/java/run/halo/app/utils/FileUtils.java
+++ b/src/main/java/run/halo/app/utils/FileUtils.java
@@ -1,5 +1,6 @@
 package run.halo.app.utils;
 
+import cn.hutool.core.io.IORuntimeException;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
@@ -259,4 +260,44 @@ public class FileUtils {
             log.warn("Failed to delete " + deletingPath);
         }
     }
+
+    /**
+     * 删除文件或者文件夹
+     *
+     * @param path path
+     * @return boolean
+     * @throws IORuntimeException IORuntimeException
+     */
+    public static boolean del(Path path) throws IORuntimeException {
+        if (Files.notExists(path)) {
+            return true;
+        }
+        try {
+            if (Files.isDirectory(path)) {
+                Files.walkFileTree(path, new SimpleFileVisitor<Path>() {
+
+                    @Override
+                    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+                        Files.delete(file);
+                        return FileVisitResult.CONTINUE;
+                    }
+
+                    @Override
+                    public FileVisitResult postVisitDirectory(Path dir, IOException e) throws IOException {
+                        if (e == null) {
+                            Files.delete(dir);
+                            return FileVisitResult.CONTINUE;
+                        } else {
+                            throw e;
+                        }
+                    }
+                });
+            } else {
+                Files.delete(path);
+            }
+        } catch (IOException e) {
+            throw new IORuntimeException(e);
+        }
+        return true;
+    }
 }