优化

app/src/main/java/io/legado/app/help/BookHelp.kt

@@ -36,18 +36,18 @@ object BookHelp {
         return String.format("%05d-%s", bookChapter.index, MD5Utils.md5Encode(bookChapter.title))
     }
 
-    private fun getBookCachePath(): String {
-        return "$downloadPath${File.separator}$cacheFolderName"
-    }
-
     fun clearCache() {
         if (downloadUri.isDocumentUri(App.INSTANCE)) {
             DocumentFile.fromTreeUri(App.INSTANCE, downloadUri)
                 ?.findFile(cacheFolderName)
                 ?.delete()
         } else {
-            FileUtils.deleteFile(getBookCachePath())
-            FileUtils.createFolderIfNotExist(getBookCachePath())
+            FileUtils.deleteFile(
+                FileUtils.getPath(
+                    File(downloadPath),
+                    subDirs = *arrayOf(cacheFolderName)
+                )
+            )
         }
     }
 

app/src/main/java/io/legado/app/utils/FileUtils.kt

@@ -13,28 +13,20 @@ import java.io.IOException
 
 object FileUtils {
 
-    fun exists(file: File, fileName: String, vararg subDirs: String): Boolean {
-        val filePath =
-            file.absolutePath + File.separator + subDirs.joinToString(File.separator) + File.separator + fileName
-        return File(filePath).exists()
+    fun exists(root: File, fileName: String, vararg subDirs: String): Boolean {
+        return getFile(root, fileName, subDirs = *subDirs).exists()
     }
 
-    fun createFileIfNotExist(file: File, fileName: String, vararg subDirs: String): File {
-        val filePath =
-            file.absolutePath + File.separator + subDirs.joinToString(File.separator) + File.separator + fileName
+    fun createFileIfNotExist(root: File, fileName: String, vararg subDirs: String): File {
+        val filePath = getPath(root, fileName, *subDirs)
         return createFileIfNotExist(filePath)
     }
 
-    fun createFileIfNotExist(file: File, vararg subDirs: String): File {
-        val filePath = file.absolutePath + File.separator + subDirs.joinToString(File.separator)
+    fun createFileIfNotExist(root: File, vararg subDirs: String): File {
+        val filePath = root.absolutePath + File.separator + subDirs.joinToString(File.separator)
         return createFolderIfNotExist(filePath)
     }
 
-    fun getCachePath(): String {
-        return App.INSTANCE.externalCacheDir?.absolutePath
-            ?: App.INSTANCE.cacheDir.absolutePath
-    }
-
     fun createFolderIfNotExist(filePath: String): File {
         val file = File(filePath)
         //如果文件夹不存在，就创建它
@@ -62,6 +54,24 @@ object FileUtils {
         return file
     }
 
+    fun getFile(file: File, fileName: String, vararg subDirs: String): File {
+        val filePath = getPath(file, fileName, *subDirs)
+        return File(filePath)
+    }
+
+    fun getFile(root: File, vararg subDirs: String): File {
+        val filePath = getPath(root, subDirs = *subDirs)
+        return File(filePath)
+    }
+
+    fun getPath(root: File, fileName: String? = null, vararg subDirs: String): String {
+        return if (fileName.isNullOrEmpty()) {
+            root.absolutePath + File.separator + subDirs.joinToString(File.separator)
+        } else {
+            root.absolutePath + File.separator + subDirs.joinToString(File.separator) + File.separator + fileName
+        }
+    }
+
     //递归删除文件夹下的数据
     @Synchronized
     fun deleteFile(filePath: String) {
@@ -79,6 +89,11 @@ object FileUtils {
         file.delete()
     }
 
+    fun getCachePath(): String {
+        return App.INSTANCE.externalCacheDir?.absolutePath
+            ?: App.INSTANCE.cacheDir.absolutePath
+    }
+
     fun getSdCardPath(): String {
         @Suppress("DEPRECATION")
         var sdCardDirectory = Environment.getExternalStorageDirectory().absolutePath