diff --git a/src/main/java/JettyLauncher.java b/src/main/java/JettyLauncher.java
index d810941..bae7ae1 100644
--- a/src/main/java/JettyLauncher.java
+++ b/src/main/java/JettyLauncher.java
@@ -19,19 +19,25 @@
             if(arg.startsWith("--") && arg.contains("=")) {
                 String[] dim = arg.split("=");
                 if(dim.length >= 2) {
-                    if(dim[0].equals("--host")) {
-                        host = dim[1];
-                    } else if(dim[0].equals("--port")) {
-                        port = Integer.parseInt(dim[1]);
-                    } else if(dim[0].equals("--prefix")) {
-                        contextPath = dim[1];
-                        if(!contextPath.startsWith("/")){
-                            contextPath = "/" + contextPath;
-                        }
-                    } else if(dim[0].equals("--gitbucket.home")){
-                        System.setProperty("gitbucket.home", dim[1]);
-                    } else if(dim[0].equals("--temp_dir")){
-                        tmpDirPath = dim[1];
+                    switch (dim[0]) {
+                        case "--host":
+                            host = dim[1];
+                            break;
+                        case "--port":
+                            port = Integer.parseInt(dim[1]);
+                            break;
+                        case "--prefix":
+                            contextPath = dim[1];
+                            if (!contextPath.startsWith("/")) {
+                                contextPath = "/" + contextPath;
+                            }
+                            break;
+                        case "--gitbucket.home":
+                            System.setProperty("gitbucket.home", dim[1]);
+                            break;
+                        case "--temp_dir":
+                            tmpDirPath = dim[1];
+                            break;
                     }
                 }
             }
diff --git a/src/main/scala/gitbucket/core/api/CreateAStatus.scala b/src/main/scala/gitbucket/core/api/CreateAStatus.scala
index 3871999..f8c087f 100644
--- a/src/main/scala/gitbucket/core/api/CreateAStatus.scala
+++ b/src/main/scala/gitbucket/core/api/CreateAStatus.scala
@@ -19,8 +19,8 @@
   def isValid: Boolean = {
     CommitState.valueOf(state).isDefined &&
       // only http
-      target_url.filterNot(f => "\\Ahttps?://".r.findPrefixOf(f).isDefined && f.length<255).isEmpty &&
-      context.filterNot(f => f.length<255).isEmpty &&
-      description.filterNot(f => f.length<1000).isEmpty
+      target_url.forall(f => "\\Ahttps?://".r.findPrefixOf(f).isDefined && f.length < 255) &&
+      context.forall(f => f.length < 255) &&
+      description.forall(f => f.length < 1000)
   }
 }
diff --git a/src/main/scala/gitbucket/core/controller/ApiController.scala b/src/main/scala/gitbucket/core/controller/ApiController.scala
index ab2a0f1..e873ae2 100644
--- a/src/main/scala/gitbucket/core/controller/ApiController.scala
+++ b/src/main/scala/gitbucket/core/controller/ApiController.scala
@@ -125,7 +125,7 @@
   get ("/api/v3/repos/:owner/:repo/branches/:branch")(referrersOnly { repository =>
     //import gitbucket.core.api._
     (for{
-      branch     <- params.get("branch") if repository.branchList.find(_ == branch).isDefined
+      branch     <- params.get("branch") if repository.branchList.contains(branch)
       br <- getBranches(repository.owner, repository.name, repository.repository.defaultBranch, repository.repository.originUserName.isEmpty).find(_.name == branch)
     } yield {
       val protection = getProtectedBranchInfo(repository.owner, repository.name, branch)
@@ -287,7 +287,7 @@
   patch("/api/v3/repos/:owner/:repo/branches/:branch")(ownerOnly { repository =>
     import gitbucket.core.api._
     (for{
-      branch     <- params.get("branch") if repository.branchList.find(_ == branch).isDefined
+      branch     <- params.get("branch") if repository.branchList.contains(branch)
       protection <- extractFromJsonBody[ApiBranchProtection.EnablingAndDisabling].map(_.protection)
       br <- getBranches(repository.owner, repository.name, repository.repository.defaultBranch, repository.repository.originUserName.isEmpty).find(_.name == branch)
     } yield {
diff --git a/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala b/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
index 0ca0305..7e016a5 100644
--- a/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
@@ -157,7 +157,7 @@
 
   /** Update default branch */
   post("/:owner/:repository/settings/update_default_branch", defaultBranchForm)(ownerOnly { (form, repository) =>
-    if(repository.branchList.find(_ == form.defaultBranch).isEmpty){
+    if(!repository.branchList.contains(form.defaultBranch)){
       redirect(s"/${repository.owner}/${repository.name}/settings/options")
     } else {
       saveRepositoryDefaultBranch(repository.owner, repository.name, form.defaultBranch)
@@ -174,7 +174,7 @@
   get("/:owner/:repository/settings/branches/:branch")(ownerOnly { repository =>
     import gitbucket.core.api._
     val branch = params("branch")
-    if(repository.branchList.find(_ == branch).isEmpty){
+    if(!repository.branchList.contains(branch)){
       redirect(s"/${repository.owner}/${repository.name}/settings/branches")
     } else {
       val protection = ApiBranchProtection(getProtectedBranchInfo(repository.owner, repository.name, branch))
diff --git a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
index 1b4ecc9..896ec82 100644
--- a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
@@ -232,7 +232,7 @@
       oldFileName = form.oldFileName,
       content     = appendNewLine(convertLineSeparator(form.content, form.lineSeparator), form.lineSeparator),
       charset     = form.charset,
-      message     = if(form.oldFileName.exists(_ == form.newFileName)){
+      message     = if(form.oldFileName.contains(form.newFileName)){
         form.message.getOrElse(s"Update ${form.newFileName}")
       } else {
         form.message.getOrElse(s"Rename ${form.oldFileName.get} to ${form.newFileName}")
@@ -614,7 +614,7 @@
 
         val permission = JGitUtil.processTree(git, headTip){ (path, tree) =>
           // Add all entries except the editing file
-          if(!newPath.exists(_ == path) && !oldPath.exists(_ == path)){
+          if(!newPath.contains(path) && !oldPath.contains(path)){
             builder.add(JGitUtil.createDirCacheEntry(path, tree.getEntryFileMode, tree.getEntryObjectId))
           }
           // Retrieve permission if file exists to keep it
diff --git a/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala b/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
index c0bc923..a2e8976 100644
--- a/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
+++ b/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
@@ -83,7 +83,7 @@
 
   def addRenderer(extension: String, renderer: Renderer): Unit = renderers += ((extension, renderer))
 
-  def getRenderer(extension: String): Renderer = renderers.get(extension).getOrElse(DefaultRenderer)
+  def getRenderer(extension: String): Renderer = renderers.getOrElse(extension, DefaultRenderer)
 
   def renderableExtensions: Seq[String] = renderers.keys.toSeq
 
diff --git a/src/main/scala/gitbucket/core/service/IssuesService.scala b/src/main/scala/gitbucket/core/service/IssuesService.scala
index c6c4085..4a9b12c 100644
--- a/src/main/scala/gitbucket/core/service/IssuesService.scala
+++ b/src/main/scala/gitbucket/core/service/IssuesService.scala
@@ -111,7 +111,7 @@
       val (_, cs) = status.head
       Some(CommitStatusInfo(
         count        = status.length,
-        successCount = status.filter(_._2.state == CommitState.SUCCESS).length,
+        successCount = status.count(_._2.state == CommitState.SUCCESS),
         context      = (if(status.length == 1) Some(cs.context) else None),
         state        = (if(status.length == 1) Some(cs.state)   else None),
         targetUrl    = (if(status.length == 1) cs.targetUrl     else None),
diff --git a/src/main/scala/gitbucket/core/service/ProtectedBranchService.scala b/src/main/scala/gitbucket/core/service/ProtectedBranchService.scala
index 577b843..d74280c 100644
--- a/src/main/scala/gitbucket/core/service/ProtectedBranchService.scala
+++ b/src/main/scala/gitbucket/core/service/ProtectedBranchService.scala
@@ -76,7 +76,7 @@
     includeAdministrators: Boolean) extends AccountService with CommitStatusService {
 
     def isAdministrator(pusher: String)(implicit session: Session): Boolean =
-      pusher == owner || getGroupMembers(owner).filter(gm => gm.userName == pusher && gm.isManager).nonEmpty
+      pusher == owner || getGroupMembers(owner).exists(gm => gm.userName == pusher && gm.isManager)
 
     /**
      * Can't be force pushed
diff --git a/src/main/scala/gitbucket/core/service/PullRequestService.scala b/src/main/scala/gitbucket/core/service/PullRequestService.scala
index 3807e55..03f2e6e 100644
--- a/src/main/scala/gitbucket/core/service/PullRequestService.scala
+++ b/src/main/scala/gitbucket/core/service/PullRequestService.scala
@@ -265,7 +265,7 @@
       val summary = stateMap.map{ case (keyState, states) => states.size+" "+keyState.name }.mkString(", ")
       state -> summary
     }
-    lazy val statusesAndRequired:List[(CommitStatus, Boolean)] = statuses.map{ s => s -> branchProtection.contexts.exists(_==s.context) }
+    lazy val statusesAndRequired:List[(CommitStatus, Boolean)] = statuses.map{ s => s -> branchProtection.contexts.contains(s.context) }
     lazy val isAllSuccess = commitStateSummary._1==CommitState.SUCCESS
   }
 }
diff --git a/src/main/scala/gitbucket/core/service/WikiService.scala b/src/main/scala/gitbucket/core/service/WikiService.scala
index c5dad27..ab034fc 100644
--- a/src/main/scala/gitbucket/core/service/WikiService.scala
+++ b/src/main/scala/gitbucket/core/service/WikiService.scala
@@ -177,7 +177,7 @@
             val headId   = git.getRepository.resolve(Constants.HEAD + "^{commit}")
 
             JGitUtil.processTree(git, headId){ (path, tree) =>
-              if(revertInfo.find(x => x.filePath == path).isEmpty){
+              if(!revertInfo.exists(x => x.filePath == path)){
                 builder.add(JGitUtil.createDirCacheEntry(path, tree.getEntryFileMode, tree.getEntryObjectId))
               }
             }
diff --git a/src/main/scala/gitbucket/core/ssh/GitCommand.scala b/src/main/scala/gitbucket/core/ssh/GitCommand.scala
index 9461803..0629c14 100644
--- a/src/main/scala/gitbucket/core/ssh/GitCommand.scala
+++ b/src/main/scala/gitbucket/core/ssh/GitCommand.scala
@@ -105,7 +105,7 @@
         }
       }
       case AuthType.DeployKeyType(key) => {
-        getDeployKeys(owner, repoName).filter(sshKey => SshUtil.str2PublicKey(sshKey.publicKey).exists(_ == key)) match {
+        getDeployKeys(owner, repoName).filter(sshKey => SshUtil.str2PublicKey(sshKey.publicKey).contains(key)) match {
           case List(_) => true
           case _ => false
         }
@@ -123,7 +123,7 @@
         }
       }
       case AuthType.DeployKeyType(key) => {
-        getDeployKeys(owner, repoName).filter(sshKey => SshUtil.str2PublicKey(sshKey.publicKey).exists(_ == key)) match {
+        getDeployKeys(owner, repoName).filter(sshKey => SshUtil.str2PublicKey(sshKey.publicKey).contains(key)) match {
           case List(x) if x.allowWrite => true
           case _ => false
         }
diff --git a/src/main/scala/gitbucket/core/ssh/PublicKeyAuthenticator.scala b/src/main/scala/gitbucket/core/ssh/PublicKeyAuthenticator.scala
index 814e3e9..e3be40d 100644
--- a/src/main/scala/gitbucket/core/ssh/PublicKeyAuthenticator.scala
+++ b/src/main/scala/gitbucket/core/ssh/PublicKeyAuthenticator.scala
@@ -68,7 +68,7 @@
   private def authenticateGenericUser(userName: String, key: PublicKey, session: ServerSession, genericUser: String)(implicit s: Session): Boolean = {
     // find all users having the key we got from ssh
     val possibleUserNames = getAllKeys().filter { sshKey =>
-      SshUtil.str2PublicKey(sshKey.publicKey).exists(_ == key)
+      SshUtil.str2PublicKey(sshKey.publicKey).contains(key)
     }.map(_.userName).distinct
 
     // determine the user - if different accounts share the same key, tough luck
@@ -85,7 +85,7 @@
     }.getOrElse {
       // search deploy keys
       val existsDeployKey = getAllDeployKeys().exists { sshKey =>
-        SshUtil.str2PublicKey(sshKey.publicKey).exists(_ == key)
+        SshUtil.str2PublicKey(sshKey.publicKey).contains(key)
       }
       if(existsDeployKey){
         // found deploy key for repository
diff --git a/src/main/scala/gitbucket/core/util/JGitUtil.scala b/src/main/scala/gitbucket/core/util/JGitUtil.scala
index ac1a9b5..3c494ae 100644
--- a/src/main/scala/gitbucket/core/util/JGitUtil.scala
+++ b/src/main/scala/gitbucket/core/util/JGitUtil.scala
@@ -952,7 +952,7 @@
    * @return the last modified commit of specified path
    */
   def getLastModifiedCommit(git: Git, startCommit: RevCommit, path: String): RevCommit = {
-    return git.log.add(startCommit).addPath(path).setMaxCount(1).call.iterator.next
+    git.log.add(startCommit).addPath(path).setMaxCount(1).call.iterator.next
   }
 
   def getBranches(owner: String, name: String, defaultBranch: String, origin: Boolean): Seq[BranchInfo] = {