重构下载文件的代码，修复文件重新下载的问题 (#485)

* 重构下载文件的代码，修复文件重新下载的问题

* fix: 修复可能得空指针问题

server/src/main/java/cn/keking/utils/DownloadUtils.java

@@ -7,15 +7,11 @@ import io.mola.galimatias.GalimatiasParseException;
 import org.apache.commons.io.FileUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.util.StringUtils;
 
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
-import java.net.HttpURLConnection;
 import java.net.URL;
-import java.net.URLDecoder;
 import java.util.UUID;
 
 import static cn.keking.utils.KkFileUtils.isFtpUrl;
@@ -40,7 +36,6 @@ public class DownloadUtils {
     public static ReturnResponse<String> downLoad(FileAttribute fileAttribute, String fileName) {
         // 忽略ssl证书
         String urlStr = null;
-        HttpURLConnection urlcon;
         try {
             SslUtils.ignoreSsl();
             urlStr = fileAttribute.getUrl().replaceAll("\\+", "%20");
@@ -49,7 +44,9 @@ public class DownloadUtils {
         }
         ReturnResponse<String> response = new ReturnResponse<>(0, "下载成功!!!", "");
         String realPath = getRelFilePath(fileName, fileAttribute);
-        if(!StringUtils.hasText(realPath)){
+
+        // 判断是否非法地址
+        if (KkFileUtils.isIllegalFileName(realPath)) {
             response.setCode(1);
             response.setContent(null);
             response.setMsg("下载失败:文件名不合法!" + urlStr);
@@ -67,57 +64,14 @@ public class DownloadUtils {
             response.setMsg(fileName);
             return response;
         }
-        if(realPath.equals("cunzhai")){
-            response.setContent(fileDir + fileName);
+        // 如果文件是否已经存在、且不强制更新，则直接返回文件路径
+        if (KkFileUtils.isExist(realPath) && !fileAttribute.forceUpdatedCache()) {
+            response.setContent(realPath);
             response.setMsg(fileName);
             return response;
         }
         try {
             URL url = WebUtils.normalizedURL(urlStr);
-            if (!urlStr.toLowerCase().startsWith("ftp:")&& !urlStr.toLowerCase().startsWith("file")){
-                urlcon=(HttpURLConnection)url.openConnection();
-                urlcon.setConnectTimeout(30000);
-                urlcon.setReadTimeout(30000);
-                urlcon.setInstanceFollowRedirects(false);
-                int responseCode = urlcon.getResponseCode();
-                if(responseCode != 200){
-                    if (responseCode == HttpURLConnection.HTTP_MOVED_PERM || responseCode == HttpURLConnection.HTTP_MOVED_TEMP) { //301 302
-                        url =new URL(urlcon.getHeaderField("Location"));
-                    }
-                    if (responseCode == 403|| responseCode == 500) { //301 302
-                        response.setCode(1);
-                        response.setContent(null);
-                        response.setMsg("下载失败:地址错误!" + urlStr);
-                        return response;
-                    }
-                    if (responseCode  == 404 ) {  //404
-                        try {
-                            urlStr = URLDecoder.decode(urlStr, "UTF-8");
-                            urlStr = URLDecoder.decode(urlStr, "UTF-8");
-                            url = WebUtils.normalizedURL(urlStr);
-                            urlcon=(HttpURLConnection)url.openConnection();
-                            urlcon.setConnectTimeout(30000);
-                            urlcon.setReadTimeout(30000);
-                            urlcon.setInstanceFollowRedirects(false);
-                            responseCode = urlcon.getResponseCode();
-                            if (responseCode == HttpURLConnection.HTTP_MOVED_PERM || responseCode == HttpURLConnection.HTTP_MOVED_TEMP) { //301 302
-                                url =new URL(urlcon.getHeaderField("Location"));
-                            }
-                            if(responseCode == 404 ||responseCode == 403|| responseCode == 500 ){
-                                response.setCode(1);
-                                response.setContent(null);
-                                response.setMsg("下载失败:地址错误!" + urlStr);
-                                return response;
-                            }
-                        } catch (UnsupportedEncodingException e) {
-                            e.printStackTrace();
-                        }finally {
-                            assert urlcon != null;
-                            urlcon.disconnect();
-                        }
-                    }
-                }
-            }
             if (!fileAttribute.getSkipDownLoad()) {
                 if (isHttpUrl(url)) {
                     File realFile = new File(realPath);
@@ -163,25 +117,12 @@ public class DownloadUtils {
         } else { // 文件后缀不一致时，以type为准(针对simText【将类txt文件转为txt】)
             fileName = fileName.replace(fileName.substring(fileName.lastIndexOf(".") + 1), type);
         }
-        // 判断是否非法地址
-        if (KkFileUtils.isIllegalFileName(fileName)) {
-            return null;
-        }
+
         String realPath = fileDir + fileName;
         File dirFile = new File(fileDir);
         if (!dirFile.exists() && !dirFile.mkdirs()) {
             logger.error("创建目录【{}】失败,可能是权限不够，请检查", fileDir);
         }
-        Boolean forceUpdatedCache = fileAttribute.forceUpdatedCache();
-        //判断是否启用强制更新功能如果启用 文件必须重新下载
-        if (null == forceUpdatedCache || !forceUpdatedCache) {
-            // 文件已在本地存在，跳过文件下载
-            File realFile = new File(realPath);
-            if (realFile.exists()) {
-                fileAttribute.setSkipDownLoad(true);
-                return "cunzhai"; //这里给的值是不能修改的 对应的是下载方法里面有个强制输出地址的
-            }
-        }
         return realPath;
     }
 

server/src/main/java/cn/keking/utils/KkFileUtils.java

@@ -34,29 +34,33 @@ public class KkFileUtils {
 
     /**
      * 检查文件名是否合规
+     *
      * @param fileName 文件名
-     * @return 合规结果,true:不合规，false:合规
+     * @return 合规结果, true:不合规，false:合规
      */
-    public static boolean isIllegalFileName(String fileName){
-        for (String str: illegalFileStrList){
-            if(fileName.contains(str)){
+    public static boolean isIllegalFileName(String fileName) {
+        for (String str : illegalFileStrList) {
+            if (fileName.contains(str)) {
                 return true;
             }
         }
         return false;
     }
+
     /**
      * 检查是否是数字
+     *
      * @param str 文件名
-     * @return 合规结果,true:不合规，false:合规
+     * @return 合规结果, true:不合规，false:合规
      */
     public static boolean isInteger(String str) {
-        if(StringUtils.hasText(str)){
+        if (StringUtils.hasText(str)) {
             boolean strResult = str.matches("-?[0-9]+.?[0-9]*");
-            return strResult ;
+            return strResult;
         }
         return false;
     }
+
     /**
      * 判断url是否是http资源
      *
@@ -102,7 +106,7 @@ public class KkFileUtils {
 
 
     public static String htmlEscape(String input) {
-        if(StringUtils.hasText(input)){
+        if (StringUtils.hasText(input)) {
             //input = input.replaceAll("\\{", "%7B").replaceAll("}", "%7D").replaceAll("\\\\", "%5C");
             String htmlStr = HtmlUtils.htmlEscape(input, "UTF-8");
             //& -> &
@@ -186,11 +190,23 @@ public class KkFileUtils {
      */
     public static boolean isAllowedUpload(String file) {
         String fileType = suffixFromFileName(file);
-            for (String type : ConfigConstants.getProhibit()) {
-            if (type.equals(fileType))
+        for (String type : ConfigConstants.getProhibit()) {
+            if (type.equals(fileType)){
                 return false;
+            }
         }
         return !ObjectUtils.isEmpty(fileType);
     }
 
+    /**
+     * 判断文件是否存在
+     *
+     * @param filePath 文件路径
+     * @return 是否存在 true:存在，false:不存在
+     */
+    public static boolean isExist(String filePath) {
+        File file = new File(filePath);
+        return file.exists();
+    }
+
 }