优化

app/src/main/java/io/legado/app/ui/book/cache/CacheViewModel.kt

@@ -280,7 +280,8 @@ class CacheViewModel(application: Application) : BaseViewModel(application) {
             exportProgress.remove(book.bookUrl)
             exportMsg[book.bookUrl] = it.localizedMessage ?: "ERROR"
             upAdapterLiveData.postValue(book.bookUrl)
-            it.printOnDebug()
+            it.printStackTrace()
+            AppLog.put("导出epub书籍<${book.name}>出错\n${it.localizedMessage}", it)
         }.onSuccess {
             exportProgress.remove(book.bookUrl)
             exportMsg[book.bookUrl] = context.getString(R.string.export_success)