feat: 优化代码

app/src/main/java/io/legado/app/help/storage/ImportOldData.kt

@@ -36,7 +36,7 @@ object ImportOldData {
 
             try {// Book source
                 val sourceFile =
-                    FileUtils.createFileIfNotExist(file, "myBookSource.json")
+                    FileUtils.getFile(file, "myBookSource.json")
                 val json = sourceFile.readText()
                 val importCount = importOldSource(json)
                 withContext(Dispatchers.Main) {
@@ -49,13 +49,18 @@ object ImportOldData {
             }
 
             try {// Replace rules
-                val ruleFile =
+                val ruleFile = FileUtils.getFile(file, "myBookReplaceRule.json")
-                    FileUtils.createFileIfNotExist(file, "myBookReplaceRule.json")
+                if (ruleFile.exists()) {
                     val json = ruleFile.readText()
                     val importCount = importOldReplaceRule(json)
                     withContext(Dispatchers.Main) {
                         context.toast("成功导入替换规则${importCount}")
                     }
+                } else {
+                    withContext(Dispatchers.Main) {
+                        context.toast("未找到替换规则")
+                    }
+                }
             } catch (e: Exception) {
                 withContext(Dispatchers.Main) {
                     context.toast("导入替换规则失败\n${e.localizedMessage}")