优化

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

@@ -171,7 +171,7 @@ class ACache private constructor(cacheDir: File, max_size: Long, max_count: Int)
      * @return JSONObject数据
      */
     fun getAsJSONObject(key: String): JSONObject? {
-        val json = getAsString(key)
+        val json = getAsString(key) ?: return null
         return try {
             JSONObject(json)
         } catch (e: Exception) {
@@ -311,17 +311,17 @@ class ACache private constructor(cacheDir: File, max_size: Long, max_count: Int)
     fun getAsObject(key: String): Any? {
         val data = getAsBinary(key)
         if (data != null) {
-            var bais: ByteArrayInputStream? = null
+            var bis: ByteArrayInputStream? = null
             var ois: ObjectInputStream? = null
             try {
-                bais = ByteArrayInputStream(data)
-                ois = ObjectInputStream(bais)
+                bis = ByteArrayInputStream(data)
+                ois = ObjectInputStream(bis)
                 return ois.readObject()
             } catch (e: Exception) {
                 e.printStackTrace()
             } finally {
                 try {
-                    bais?.close()
+                    bis?.close()
                 } catch (e: IOException) {
                     e.printStackTrace()
                 }

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

@@ -43,7 +43,7 @@ object FileUtils {
             val storageVolumeClazz = Class.forName("android.os.storage.StorageVolume")
             val getPath = storageVolumeClazz.getMethod("getPath")
 
-            val invokeVolumeList = getVolumeList.invoke(storageManager)
+            val invokeVolumeList = getVolumeList.invoke(storageManager) ?: return null
             val length = Array.getLength(invokeVolumeList)
 
             val list = ArrayList<String>()