优化

app/src/main/java/io/legado/app/ui/main/bookshelf/BookshelfViewModel.kt

@@ -1,6 +1,7 @@
 package io.legado.app.ui.main.bookshelf
 
 import android.app.Application
+import com.google.gson.stream.JsonWriter
 import io.legado.app.R
 import io.legado.app.base.BaseViewModel
 import io.legado.app.data.appDb
@@ -14,6 +15,9 @@ import io.legado.app.model.webBook.WebBook
 import io.legado.app.utils.*
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.isActive
+import java.io.File
+import java.io.FileOutputStream
+import java.io.OutputStreamWriter
 
 class BookshelfViewModel(application: Application) : BaseViewModel(application) {
 
@@ -66,19 +70,33 @@ class BookshelfViewModel(application: Application) : BaseViewModel(application)
         }
     }
 
-    fun exportBookshelf(books: List<Book>?, success: (json: String) -> Unit) {
+    fun exportBookshelf(books: List<Book>?, success: (file: File) -> Unit) {
         execute {
-            val exportList = arrayListOf<Map<String, String?>>()
-            books?.forEach {
+            books?.let {
+                val path = "${context.filesDir}/books.json"
+                FileUtils.delete(path)
+                val file = FileUtils.createFileWithReplace(path)
+                @Suppress("BlockingMethodInNonBlockingContext")
+                FileOutputStream(file).use { out ->
+                    val writer = JsonWriter(OutputStreamWriter(out, "UTF-8"))
+                    writer.setIndent("  ")
+                    writer.beginArray()
+                    books.forEach {
                         val bookMap = hashMapOf<String, String?>()
                         bookMap["name"] = it.name
                         bookMap["author"] = it.author
                         bookMap["intro"] = it.getDisplayIntro()
-                exportList.add(bookMap)
+                        GSON.toJson(bookMap, bookMap::class.java, writer)
                     }
-            GSON.toJson(exportList)
+                    writer.endArray()
+                    writer.close()
+                }
+                file
+            } ?: throw NoStackTraceException("书籍不能为空")
         }.onSuccess {
             success(it)
+        }.onError {
+            context.toastOnUi("导出书籍出错\n${it.localizedMessage}")
         }
     }
 

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

@@ -49,12 +49,12 @@ fun Gson.writeToOutputStream(out: OutputStream, any: Any) {
         writer.beginArray()
         any.forEach {
             it?.let {
-                GSON.toJson(it, it::class.java, writer)
+                toJson(it, it::class.java, writer)
             }
         }
         writer.endArray()
     } else {
-        GSON.toJson(any, any::class.java, writer)
+        toJson(any, any::class.java, writer)
     }
     writer.close()
 }