优化

app/src/main/java/io/legado/app/data/entities/Book.kt

@@ -19,7 +19,7 @@ data class Book(
     var bookUrl: String = "",                   // 详情页Url(本地书源存储完整文件路径)
     var tocUrl: String = "",                    // 目录页Url (toc=table of Contents)
     var origin: String = BookType.local,        // 书源URL(默认BookType.local)
-    var originName: String = "",                //书源名称
+    var originName: String = "",                //书源名称 or 本地书籍文件名
     var name: String = "",                   // 书籍名称(书源获取)
     var author: String = "",                 // 作者名称(书源获取)
     override var kind: String? = null,                    // 分类信息(书源获取)

app/src/main/java/io/legado/app/model/localBook/AnalyzeTxtFile.kt

@@ -2,20 +2,33 @@ package io.legado.app.model.localBook
 
 import android.content.Context
 import android.net.Uri
+import io.legado.app.App
 import io.legado.app.data.entities.Book
+import io.legado.app.utils.DocumentUtils
 import io.legado.app.utils.EncodingDetect
+import io.legado.app.utils.FileUtils
+import java.io.File
 
 object AnalyzeTxtFile {
-
+    private const val folderName = "bookTxt"
+    private val cacheFolder: File by lazy {
+        val rootFile = App.INSTANCE.getExternalFilesDir(null)
+            ?: App.INSTANCE.externalCacheDir
+            ?: App.INSTANCE.cacheDir
+        FileUtils.createFileIfNotExist(rootFile, subDirs = *arrayOf(folderName))
+    }
 
     fun analyze(context: Context, book: Book) {
-        context.contentResolver.openInputStream(Uri.parse(book.bookUrl))?.use { stream ->
-            val rawByteArray = ByteArray(2000)
-            stream.read(rawByteArray)
-            book.charset = EncodingDetect.getJavaEncode(rawByteArray)
-
-
+        val uri = Uri.parse(book.bookUrl)
+        val bookFile = FileUtils.getFile(cacheFolder, book.originName, subDirs = *arrayOf())
+        if (!bookFile.exists()) {
+            bookFile.createNewFile()
+            DocumentUtils.readBytes(context, uri)?.let {
+                bookFile.writeBytes(it)
+            }
         }
+        book.charset = EncodingDetect.getEncode(bookFile)
+
     }
 
 }

app/src/main/java/io/legado/app/ui/importbook/ImportBookViewModel.kt

@@ -23,7 +23,12 @@ class ImportBookViewModel(application: Application) : BaseViewModel(application)
                         if (smhStart != -1 && smhEnd != -1) {
                             name = (name.substring(smhStart + 1, smhEnd))
                         }
-                        val book = Book(bookUrl = uriStr, name = name, author = author)
+                        val book = Book(
+                            bookUrl = uriStr,
+                            name = name,
+                            author = author,
+                            originName = fileName
+                        )
                         App.db.bookDao().insert(book)
                     }
                 }

app/src/main/java/io/legado/app/utils/EncodingDetect.java

@@ -62,10 +62,10 @@ public class EncodingDetect {
             }
         } catch (Exception ignored) {
         }
-        return getJavaEncode(bytes);
+        return getEncode(bytes);
     }
 
-    public static String getJavaEncode(@NonNull byte[] bytes) {
+    public static String getEncode(@NonNull byte[] bytes) {
         int len = bytes.length > 2000 ? 2000 : bytes.length;
         byte[] cBytes = new byte[len];
         System.arraycopy(bytes, 0, cBytes, 0, len);
@@ -83,7 +83,7 @@ public class EncodingDetect {
     /**
      * 得到文件的编码
      */
-    public static String getJavaEncode(@NonNull String filePath) {
+    public static String getEncode(@NonNull String filePath) {
         BytesEncodingDetect s = new BytesEncodingDetect();
         String fileCode = BytesEncodingDetect.javaname[s
                 .detectEncoding(new File(filePath))];
@@ -102,7 +102,7 @@ public class EncodingDetect {
     /**
      * 得到文件的编码
      */
-    public static String getJavaEncode(@NonNull File file) {
+    public static String getEncode(@NonNull File file) {
         BytesEncodingDetect s = new BytesEncodingDetect();
         String fileCode = BytesEncodingDetect.javaname[s.detectEncoding(file)];
         // UTF-16LE 特殊处理