diff --git a/src/main/java/net/lamgc/oracle/sentry/OracleIdentityManager.java b/src/main/java/net/lamgc/oracle/sentry/OracleIdentityManager.java
index 031477d..07afc30 100644
--- a/src/main/java/net/lamgc/oracle/sentry/OracleIdentityManager.java
+++ b/src/main/java/net/lamgc/oracle/sentry/OracleIdentityManager.java
@@ -13,7 +13,6 @@ import com.oracle.bmc.identity.requests.GetUserRequest;
 import com.oracle.bmc.identity.responses.GetUserResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.stereotype.Component;
 
 import java.io.File;
 import java.io.FileNotFoundException;
diff --git a/src/main/java/net/lamgc/oracle/sentry/common/OutputStreamWrapper.java b/src/main/java/net/lamgc/oracle/sentry/common/OutputStreamWrapper.java
index 3a4a4b6..c41e56d 100644
--- a/src/main/java/net/lamgc/oracle/sentry/common/OutputStreamWrapper.java
+++ b/src/main/java/net/lamgc/oracle/sentry/common/OutputStreamWrapper.java
@@ -1,7 +1,6 @@
 package net.lamgc.oracle.sentry.common;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.OutputStream;
 
 public class OutputStreamWrapper extends OutputStream {
diff --git a/src/main/java/net/lamgc/oracle/sentry/oci/compute/ssh/SshAuthInfoSerializer.java b/src/main/java/net/lamgc/oracle/sentry/oci/compute/ssh/SshAuthInfoSerializer.java
index 7c08911..92309ed 100644
--- a/src/main/java/net/lamgc/oracle/sentry/oci/compute/ssh/SshAuthInfoSerializer.java
+++ b/src/main/java/net/lamgc/oracle/sentry/oci/compute/ssh/SshAuthInfoSerializer.java
@@ -4,10 +4,8 @@ import com.google.common.base.Strings;
 import com.google.gson.*;
 import org.apache.sshd.common.config.keys.KeyUtils;
 import org.apache.sshd.common.config.keys.PublicKeyEntry;
-import org.apache.sshd.common.config.keys.PublicKeyEntryDataResolver;
 import org.apache.sshd.common.config.keys.PublicKeyEntryDecoder;
 
-import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.lang.reflect.Type;
@@ -23,6 +21,8 @@ public final class SshAuthInfoSerializer implements JsonSerializer<SshAuthInfo>,
 
     public final static SshAuthInfoSerializer INSTANCE = new SshAuthInfoSerializer();
 
+    private SshAuthInfoSerializer() {}
+
     @Override
     public SshAuthInfo deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
         if (!json.isJsonObject()) {
@@ -109,22 +109,6 @@ public final class SshAuthInfoSerializer implements JsonSerializer<SshAuthInfo>,
         StringBuilder builder = new StringBuilder();
         PublicKeyEntry.appendPublicKeyEntry(builder, key);
         return builder.toString();
-        /*
-        // 以下代码改写自 KnownHosts 的那个认证器, 说实话翻一下官方代码还可以找到不错的东西.
-        @SuppressWarnings("unchecked") PublicKeyEntryDecoder<PublicKey, ?> decoder
-                = (PublicKeyEntryDecoder<PublicKey, ?>) KeyUtils.getPublicKeyEntryDecoder(key);
-        if (decoder == null) {
-            throw new JsonParseException("Cannot retrieve decoder for key=" + key.getAlgorithm());
-        }
-
-        try (ByteArrayOutputStream s = new ByteArrayOutputStream(Byte.MAX_VALUE)) {
-            String keyType = decoder.encodePublicKey(s, key);
-            byte[] bytes = s.toByteArray();
-            PublicKeyEntryDataResolver encoder = PublicKeyEntry.resolveKeyDataEntryResolver(keyType);
-            return encoder.encodeEntryKeyData(bytes);
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }*/
     }
 
 }
diff --git a/src/main/java/net/lamgc/oracle/sentry/script/Script.java b/src/main/java/net/lamgc/oracle/sentry/script/Script.java
index a6dd598..9812cc9 100644
--- a/src/main/java/net/lamgc/oracle/sentry/script/Script.java
+++ b/src/main/java/net/lamgc/oracle/sentry/script/Script.java
@@ -1,8 +1,5 @@
 package net.lamgc.oracle.sentry.script;
 
-import groovy.lang.Closure;
-import groovy.lang.DelegatesTo;
-
 /**
  * @author LamGC
  */
diff --git a/src/main/java/net/lamgc/oracle/sentry/script/groovy/GroovyDslDelegate.java b/src/main/java/net/lamgc/oracle/sentry/script/groovy/GroovyDslDelegate.java
index 689fa4e..8c0a6c0 100644
--- a/src/main/java/net/lamgc/oracle/sentry/script/groovy/GroovyDslDelegate.java
+++ b/src/main/java/net/lamgc/oracle/sentry/script/groovy/GroovyDslDelegate.java
@@ -1,17 +1,11 @@
 package net.lamgc.oracle.sentry.script.groovy;
 
-import net.lamgc.oracle.sentry.ComputeInstanceManager;
-import net.lamgc.oracle.sentry.script.*;
-
 import groovy.lang.Closure;
 import groovy.lang.DelegatesTo;
 import net.lamgc.oracle.sentry.script.groovy.trigger.*;
 import net.lamgc.oracle.sentry.script.tools.http.ScriptHttpClient;
 import org.codehaus.groovy.runtime.DefaultGroovyMethods;
 
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
-
 /**
  * Groovy DSL 脚本的父类.
  * @author LamGC