优化

app/src/main/java/io/legado/app/service/ExportBookService.kt

@@ -41,6 +41,7 @@ import io.legado.app.utils.activityPendingIntent
 import io.legado.app.utils.cnCompare
 import io.legado.app.utils.createFolderIfNotExist
 import io.legado.app.utils.isContentScheme
+import io.legado.app.utils.outputStream
 import io.legado.app.utils.postEvent
 import io.legado.app.utils.readBytes
 import io.legado.app.utils.readText
@@ -230,9 +231,11 @@ class ExportBookService : BaseService() {
         DocumentUtils.delete(doc, filename)
         val bookDoc = DocumentUtils.createFileIfNotExist(doc, filename)
             ?: throw NoStackTraceException("创建文档失败，请尝试重新设置导出文件夹")
+        val charset = Charset.forName(AppConfig.exportCharset)
         contentResolver.openOutputStream(bookDoc.uri, "wa")?.use { bookOs ->
+            BufferedOutputStream(bookOs, 64 * 1024).use { bos ->
                 getAllContents(book) { text, srcList ->
-                bookOs.write(text.toByteArray(Charset.forName(AppConfig.exportCharset)))
+                    bos.write(text.toByteArray(charset))
                     srcList?.forEach {
                         val vFile = BookHelp.getImage(book, it.src)
                         if (vFile.exists()) {
@@ -249,6 +252,7 @@ class ExportBookService : BaseService() {
                     }
                 }
             }
+        }
         if (AppConfig.exportToWebDav) {
             // 导出到webdav
             AppWebDav.exportWebDav(bookDoc.uri, filename)
@@ -259,8 +263,11 @@ class ExportBookService : BaseService() {
         val filename = book.getExportFileName("txt")
         val bookPath = FileUtils.getPath(file, filename)
         val bookFile = FileUtils.createFileWithReplace(bookPath)
+        val charset = Charset.forName(AppConfig.exportCharset)
+        val bos = BufferedOutputStream(bookFile.outputStream(true), 64 * 1024)
+        bos.use {
             getAllContents(book) { text, srcList ->
-            bookFile.appendText(text, Charset.forName(AppConfig.exportCharset))
+                bos.write(text.toByteArray(charset))
                 srcList?.forEach {
                     val vFile = BookHelp.getImage(book, it.src)
                     if (vFile.exists()) {
@@ -274,6 +281,7 @@ class ExportBookService : BaseService() {
                     }
                 }
             }
+        }
         if (AppConfig.exportToWebDav) {
             AppWebDav.exportWebDav(Uri.fromFile(bookFile), filename) // 导出到webdav
         }

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

@@ -4,6 +4,7 @@ package io.legado.app.utils
 
 import android.net.Uri
 import java.io.File
+import java.io.FileOutputStream
 
 fun File.getFile(vararg subDirFiles: String): File {
     val path = FileUtils.getPath(this, *subDirFiles)
@@ -79,3 +80,7 @@ fun File.checkWrite(): Boolean {
         false
     }
 }
+
+fun File.outputStream(append: Boolean = false): FileOutputStream {
+    return FileOutputStream(this, append)
+}