diff --git a/src/main/scala/gitbucket/core/api/ApiContents.scala b/src/main/scala/gitbucket/core/api/ApiContents.scala
index 1d5753b..8b3735a 100644
--- a/src/main/scala/gitbucket/core/api/ApiContents.scala
+++ b/src/main/scala/gitbucket/core/api/ApiContents.scala
@@ -1,8 +1,9 @@
 package gitbucket.core.api
 
+import java.util.Base64
+
 import gitbucket.core.util.JGitUtil.FileInfo
 import gitbucket.core.util.RepositoryName
-import org.apache.commons.codec.binary.Base64
 
 case class ApiContents(
   `type`: String,
@@ -20,7 +21,7 @@
       ApiContents("dir", fileInfo.name, fileInfo.path, fileInfo.commitId, None, None)(repositoryName)
     } else {
       content.map(arr =>
-        ApiContents("file", fileInfo.name, fileInfo.path, fileInfo.commitId, Some(Base64.encodeBase64String(arr)), Some("base64"))(repositoryName)
+        ApiContents("file", fileInfo.name, fileInfo.path, fileInfo.commitId, Some(Base64.getEncoder.encodeToString(arr)), Some("base64"))(repositoryName)
       ).getOrElse(ApiContents("file", fileInfo.name, fileInfo.path, fileInfo.commitId, None, None)(repositoryName))
     }
   }
diff --git a/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala b/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
index 7ba1026..b299004 100644
--- a/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
+++ b/src/main/scala/gitbucket/core/plugin/PluginRegistory.scala
@@ -2,6 +2,7 @@
 
 import java.io.{File, FilenameFilter, InputStream}
 import java.net.URLClassLoader
+import java.util.Base64
 import javax.servlet.ServletContext
 
 import gitbucket.core.controller.{Context, ControllerBase}
@@ -15,7 +16,6 @@
 import io.github.gitbucket.solidbase.Solidbase
 import io.github.gitbucket.solidbase.manager.JDBCVersionManager
 import io.github.gitbucket.solidbase.model.Module
-import org.apache.commons.codec.binary.{Base64, StringUtils}
 import org.slf4j.LoggerFactory
 
 import scala.collection.mutable
@@ -54,7 +54,7 @@
   def getPlugins(): List[PluginInfo] = plugins.toList
 
   def addImage(id: String, bytes: Array[Byte]): Unit = {
-    val encoded = StringUtils.newStringUtf8(Base64.encodeBase64(bytes, false))
+    val encoded = Base64.getEncoder.encodeToString(bytes)
     images += ((id, encoded))
   }
 
diff --git a/src/main/scala/gitbucket/core/ssh/SshUtil.scala b/src/main/scala/gitbucket/core/ssh/SshUtil.scala
index 42167ed..62eb97a 100644
--- a/src/main/scala/gitbucket/core/ssh/SshUtil.scala
+++ b/src/main/scala/gitbucket/core/ssh/SshUtil.scala
@@ -1,8 +1,8 @@
 package gitbucket.core.ssh
 
 import java.security.PublicKey
+import java.util.Base64
 
-import org.apache.commons.codec.binary.Base64
 import org.apache.sshd.common.config.keys.KeyUtils
 import org.apache.sshd.common.util.buffer.ByteArrayBuffer
 import org.eclipse.jgit.lib.Constants
@@ -22,7 +22,7 @@
     }
     try {
       val encodedKey = parts(1)
-      val decode = Base64.decodeBase64(Constants.encodeASCII(encodedKey))
+      val decode = Base64.getDecoder.decode(Constants.encodeASCII(encodedKey))
       Some(new ByteArrayBuffer(decode).getRawPublicKey)
     } catch {
       case e: Throwable =>
diff --git a/src/main/scala/gitbucket/core/util/AuthUtil.scala b/src/main/scala/gitbucket/core/util/AuthUtil.scala
index 7a83c13..5d937ca 100644
--- a/src/main/scala/gitbucket/core/util/AuthUtil.scala
+++ b/src/main/scala/gitbucket/core/util/AuthUtil.scala
@@ -1,5 +1,6 @@
 package gitbucket.core.util
 
+import java.util.Base64
 import javax.servlet.http.HttpServletResponse
 
 /**
@@ -13,9 +14,9 @@
 
   def decodeAuthHeader(header: String): String = {
     try {
-      new String(new sun.misc.BASE64Decoder().decodeBuffer(header.substring(6)))
+      new String(Base64.getDecoder.decode(header.substring(6)))
     } catch {
       case _: Throwable => ""
     }
   }
-}
\ No newline at end of file
+}
diff --git a/src/main/scala/gitbucket/core/util/StringUtil.scala b/src/main/scala/gitbucket/core/util/StringUtil.scala
index 587df35..d1eadf3 100644
--- a/src/main/scala/gitbucket/core/util/StringUtil.scala
+++ b/src/main/scala/gitbucket/core/util/StringUtil.scala
@@ -1,12 +1,12 @@
 package gitbucket.core.util
 
 import java.net.{URLDecoder, URLEncoder}
+import java.util.Base64
 
 import org.mozilla.universalchardet.UniversalDetector
 import SyntaxSugars._
 import org.apache.commons.io.input.BOMInputStream
 import org.apache.commons.io.IOUtils
-import org.apache.commons.codec.binary.Base64
 
 import scala.util.control.Exception._
 
@@ -34,14 +34,14 @@
     val spec = new javax.crypto.spec.SecretKeySpec(BlowfishKey.getBytes(), "Blowfish")
     val cipher = javax.crypto.Cipher.getInstance("Blowfish")
     cipher.init(javax.crypto.Cipher.ENCRYPT_MODE, spec)
-    new String(Base64.encodeBase64(cipher.doFinal(value.getBytes("UTF-8"))), "UTF-8")
+    Base64.getEncoder.encodeToString(cipher.doFinal(value.getBytes("UTF-8")))
   }
 
   def decodeBlowfish(value: String): String = {
     val spec = new javax.crypto.spec.SecretKeySpec(BlowfishKey.getBytes(), "Blowfish")
     val cipher = javax.crypto.Cipher.getInstance("Blowfish")
     cipher.init(javax.crypto.Cipher.DECRYPT_MODE, spec)
-    new String(cipher.doFinal(Base64.decodeBase64(value)), "UTF-8")
+    new String(cipher.doFinal(Base64.getDecoder.decode(value)), "UTF-8")
   }
 
   def urlEncode(value: String): String = URLEncoder.encode(value, "UTF-8").replace("+", "%20")