优化

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

@@ -1,7 +1,6 @@
 package io.legado.app.model.localBook
 
 import android.graphics.Bitmap
-import android.graphics.BitmapFactory
 import android.text.TextUtils
 import io.legado.app.data.entities.Book
 import io.legado.app.data.entities.BookChapter
@@ -85,11 +84,13 @@ class EpubFile(var book: Book) {
                 if (!File(book.coverUrl!!).exists()) {
                     /*部分书籍DRM处理后，封面获取异常，待优化*/
                     it.coverImage?.inputStream?.use { input ->
-                        val cover = BitmapFactory.decodeStream(input)
-                        val out = FileOutputStream(FileUtils.createFileIfNotExist(book.coverUrl!!))
-                        cover.compress(Bitmap.CompressFormat.JPEG, 90, out)
-                        out.flush()
-                        out.close()
+                        BitmapUtils.decodeBitmap(input)?.let { cover ->
+                            val out =
+                                FileOutputStream(FileUtils.createFileIfNotExist(book.coverUrl!!))
+                            cover.compress(Bitmap.CompressFormat.JPEG, 90, out)
+                            out.flush()
+                            out.close()
+                        }
                     }
                 }
             }

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

@@ -10,6 +10,7 @@ import android.graphics.Color
 import com.google.android.renderscript.Toolkit
 import java.io.FileInputStream
 import java.io.IOException
+import java.io.InputStream
 import kotlin.math.*
 
 
@@ -81,6 +82,23 @@ object BitmapUtils {
         }
     }
 
+    /** 从path中获取Bitmap图片
+     * @param path 图片路径
+     * @return
+     */
+    @Throws(IOException::class)
+    fun decodeBitmap(inputStream: InputStream): Bitmap? {
+        return inputStream.use {
+            val opts = BitmapFactory.Options()
+            opts.inJustDecodeBounds = true
+
+            BitmapFactory.decodeStream(inputStream, null, opts)
+            opts.inSampleSize = computeSampleSize(opts, -1, 128 * 128)
+            opts.inJustDecodeBounds = false
+            BitmapFactory.decodeStream(inputStream, null, opts)
+        }
+    }
+
     /**
      * 以最省内存的方式读取本地资源的图片
      * @param context 设备上下文