diff --git a/.gitignore b/.gitignore
index 04fb0b4f1..5ba10ef1c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
 *.iml
 .gradle
-/local.properties
+local.properties
 .DS_Store
 /build
 /captures
@@ -12,5 +12,5 @@ node_modules/
 /app/google
 /app/gradle.properties
 package-lock.json
-.idea/*
+.idea/
 
diff --git a/app/src/main/java/io/legado/app/data/entities/ReplaceRule.kt b/app/src/main/java/io/legado/app/data/entities/ReplaceRule.kt
index 62586271a..a8e375a28 100644
--- a/app/src/main/java/io/legado/app/data/entities/ReplaceRule.kt
+++ b/app/src/main/java/io/legado/app/data/entities/ReplaceRule.kt
@@ -7,6 +7,7 @@ import androidx.room.Entity
 import androidx.room.Index
 import androidx.room.PrimaryKey
 import io.legado.app.R
+import io.legado.app.constant.AppLog
 import io.legado.app.exception.NoStackTraceException
 import kotlinx.parcelize.Parcelize
 import splitties.init.appCtx
@@ -84,6 +85,7 @@ data class ReplaceRule(
             try {
                 Pattern.compile(pattern)
             } catch (ex: PatternSyntaxException) {
+                AppLog.put(ex.message)
                 return false
             }
         }
diff --git a/app/src/main/java/io/legado/app/help/book/BookExtensions.kt b/app/src/main/java/io/legado/app/help/book/BookExtensions.kt
index db1d15b9e..d5c2b821e 100644
--- a/app/src/main/java/io/legado/app/help/book/BookExtensions.kt
+++ b/app/src/main/java/io/legado/app/help/book/BookExtensions.kt
@@ -243,7 +243,7 @@ fun Book.getExportFileName(suffix: String): String {
         RhinoScriptEngine.eval(jsStr, bindings).toString() + "." + suffix
     }.onFailure {
         AppLog.put("导出书名规则错误,使用默认规则\n${it.localizedMessage}", it)
-    }.getOrDefault("${name} 作者：${getRealAuthor()}.$suffix")
+    }.getOrDefault("$name 作者：${getRealAuthor()}.$suffix")
 }
 
 /**
diff --git a/app/src/main/java/io/legado/app/help/http/ObsoleteUrlFactory.kt b/app/src/main/java/io/legado/app/help/http/ObsoleteUrlFactory.kt
index 39dc334c6..5d9a67b36 100644
--- a/app/src/main/java/io/legado/app/help/http/ObsoleteUrlFactory.kt
+++ b/app/src/main/java/io/legado/app/help/http/ObsoleteUrlFactory.kt
@@ -1,5 +1,7 @@
 package io.legado.app.help.http
 
+import android.os.Build
+import androidx.annotation.RequiresApi
 import io.legado.app.help.http.CookieManager.cookieJarHeader
 import io.legado.app.help.http.SSLHelper.unsafeTrustManager
 import okhttp3.Call
@@ -797,6 +799,7 @@ class ObsoleteUrlFactory(private var client: OkHttpClient) : URLStreamHandlerFac
         }
 
         // Should only be invoked on Java 8+ or Android API 24+.
+        @RequiresApi(Build.VERSION_CODES.N)
         override fun getContentLengthLong(): Long {
             return delegate.contentLengthLong
         }
@@ -846,6 +849,7 @@ class ObsoleteUrlFactory(private var client: OkHttpClient) : URLStreamHandlerFac
         }
 
         // Should only be invoked on Java 8+ or Android API 24+.
+        @RequiresApi(Build.VERSION_CODES.N)
         override fun getHeaderFieldLong(field: String, defaultValue: Long): Long {
             return delegate.getHeaderFieldLong(field, defaultValue)
         }
diff --git a/app/src/main/java/io/legado/app/lib/prefs/Preference.kt b/app/src/main/java/io/legado/app/lib/prefs/Preference.kt
index 784c2972b..619b5cc98 100644
--- a/app/src/main/java/io/legado/app/lib/prefs/Preference.kt
+++ b/app/src/main/java/io/legado/app/lib/prefs/Preference.kt
@@ -51,7 +51,7 @@ open class Preference(context: Context, attrs: AttributeSet) :
             val tvTitle = viewHolder.findViewById(R.id.preference_title) as? TextView
             tvTitle?.let {
                 tvTitle.text = title
-                tvTitle.isVisible = title != null && title.isNotEmpty()
+                tvTitle.isVisible = !title.isNullOrEmpty()
             }
             val tvSummary = viewHolder.findViewById(R.id.preference_desc) as? TextView
             tvSummary?.let {
diff --git a/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSonPath.kt b/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSonPath.kt
index b5b672e5b..71d9006ce 100644
--- a/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSonPath.kt
+++ b/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSonPath.kt
@@ -143,7 +143,7 @@ class AnalyzeByJSonPath(json: Any) {
             val results = ArrayList<ArrayList<*>>()
             for (rl in rules) {
                 val temp = getList(rl)
-                if (temp != null && temp.isNotEmpty()) {
+                if (!temp.isNullOrEmpty()) {
                     results.add(temp)
                     if (temp.isNotEmpty() && ruleAnalyzes.elementsType == "||") {
                         break
diff --git a/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSoup.kt b/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSoup.kt
index 05ae18c68..4963df95f 100644
--- a/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSoup.kt
+++ b/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByJSoup.kt
@@ -303,7 +303,7 @@ class AnalyzeByJSoup(doc: Any) {
                 }
 
             val len = elements.size
-            val lastIndexes = (indexDefault.size - 1).takeIf { it != -1 } ?: indexes.size - 1
+            val lastIndexes = (indexDefault.size - 1).takeIf { it != -1 } ?: (indexes.size - 1)
             val indexSet = mutableSetOf<Int>()
 
             /**
diff --git a/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByXPath.kt b/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByXPath.kt
index 0495a0916..b0d52cf3a 100644
--- a/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByXPath.kt
+++ b/app/src/main/java/io/legado/app/model/analyzeRule/AnalyzeByXPath.kt
@@ -63,7 +63,7 @@ class AnalyzeByXPath(doc: Any) {
             val results = ArrayList<List<JXNode>>()
             for (rl in rules) {
                 val temp = getElements(rl)
-                if (temp != null && temp.isNotEmpty()) {
+                if (!temp.isNullOrEmpty()) {
                     results.add(temp)
                     if (temp.isNotEmpty() && ruleAnalyzes.elementsType == "||") {
                         break
diff --git a/app/src/main/java/io/legado/app/model/localBook/PdfFile.kt b/app/src/main/java/io/legado/app/model/localBook/PdfFile.kt
index 6b44617dd..4b7e0433a 100644
--- a/app/src/main/java/io/legado/app/model/localBook/PdfFile.kt
+++ b/app/src/main/java/io/legado/app/model/localBook/PdfFile.kt
@@ -80,9 +80,7 @@ class PdfFile(var book: Book) {
                 if (!File(book.coverUrl!!).exists()) {
 
                     FileOutputStream(FileUtils.createFileIfNotExist(book.coverUrl!!)).use { out ->
-                        openPdfPage(renderer, 0)?.let { cover ->
-                            cover.compress(Bitmap.CompressFormat.JPEG, 90, out)
-                        }
+                        openPdfPage(renderer, 0)?.compress(Bitmap.CompressFormat.JPEG, 90, out)
                         out.flush()
                     }
                 }
@@ -159,7 +157,7 @@ class PdfFile(var book: Book) {
 
                 buildString {
                     val start = chapter.index * PAGE_SIZE
-                    val end = Math.min((chapter.index + 1) * PAGE_SIZE, renderer.pageCount)
+                    val end = ((chapter.index + 1) * PAGE_SIZE).coerceAtMost(renderer.pageCount)
                     (start until end).forEach {
                         append("<img src=").append('"').append(it).append('"').append(" >")
                             .append('\n')
diff --git a/app/src/main/java/io/legado/app/ui/widget/anima/RefreshProgressBar.kt b/app/src/main/java/io/legado/app/ui/widget/anima/RefreshProgressBar.kt
index 3a0af5b03..ad2a46b39 100644
--- a/app/src/main/java/io/legado/app/ui/widget/anima/RefreshProgressBar.kt
+++ b/app/src/main/java/io/legado/app/ui/widget/anima/RefreshProgressBar.kt
@@ -75,9 +75,6 @@ class RefreshProgressBar @JvmOverloads constructor(
 
         if (secondDurProgress > 0 && secondMaxProgress > 0) {
             var secondDur = secondDurProgress
-            if (secondDur < 0) {
-                secondDur = 0
-            }
             if (secondDur > secondMaxProgress) {
                 secondDur = secondMaxProgress
             }
diff --git a/app/src/main/java/io/legado/app/ui/widget/code/CodeViewExtensions.kt b/app/src/main/java/io/legado/app/ui/widget/code/CodeViewExtensions.kt
index e8d92759e..afefa8cd9 100644
--- a/app/src/main/java/io/legado/app/ui/widget/code/CodeViewExtensions.kt
+++ b/app/src/main/java/io/legado/app/ui/widget/code/CodeViewExtensions.kt
@@ -13,7 +13,7 @@ val legadoPattern: Pattern = Pattern.compile("\\|\\||&&|%%|@js:|@Json:|@css:|@@|
 val jsonPattern: Pattern = Pattern.compile("\"[A-Za-z0-9]*?\"\\:|\"|\\{|\\}|\\[|\\]")
 val wrapPattern: Pattern = Pattern.compile("\\\\n")
 val operationPattern: Pattern =
-    Pattern.compile(":|==|>|<|!=|>=|<=|->|=|>|<|%|-|-=|%=|\\+|\\-|\\-=|\\+=|\\^|\\&|\\|::|\\?|\\*")
+    Pattern.compile(":|==|>|<|!=|>=|<=|->|=|%|-|-=|%=|\\+|\\-|\\-=|\\+=|\\^|\\&|\\|::|\\?|\\*")
 val jsPattern: Pattern = Pattern.compile("var")
 
 fun CodeView.addLegadoPattern() {
diff --git a/build.gradle b/build.gradle
index c21da313c..b7fbe93f3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -23,5 +23,5 @@ plugins {
 }
 
 tasks.register('clean', Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }