diff --git a/core/src/main/java/hudson/FilePath.java b/core/src/main/java/hudson/FilePath.java
index 216b361c89..ef4867ea0a 100644
--- a/core/src/main/java/hudson/FilePath.java
+++ b/core/src/main/java/hudson/FilePath.java
@@ -1639,7 +1639,7 @@ public final class FilePath implements SerializableOnlyOverRemoting {
             } else {
                 s = new String[]{prefix, suffix};
             }
-            String name = StringUtils.join(s, ".");
+            String name = String.join(".", s);
             return new FilePath(this, act(new CreateTempDir(name)));
         } catch (IOException e) {
             throw new IOException("Failed to create a temp directory on "+remote,e);
diff --git a/core/src/main/java/hudson/TcpSlaveAgentListener.java b/core/src/main/java/hudson/TcpSlaveAgentListener.java
index 32a8741b9a..e7875e95bd 100644
--- a/core/src/main/java/hudson/TcpSlaveAgentListener.java
+++ b/core/src/main/java/hudson/TcpSlaveAgentListener.java
@@ -57,7 +57,6 @@ import jenkins.slaves.RemotingVersionInfo;
 import jenkins.util.SystemProperties;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.io.output.NullOutputStream;
-import org.apache.commons.lang.StringUtils;
 import org.jenkinsci.Symbol;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
@@ -159,7 +158,7 @@ public final class TcpSlaveAgentListener extends Thread {
      * @since 2.16
      */
     public String getAgentProtocolNames() {
-        return StringUtils.join(Jenkins.get().getAgentProtocols(), ", ");
+        return String.join(", ", Jenkins.get().getAgentProtocols());
     }
 
     /**
diff --git a/core/src/main/java/hudson/logging/LogRecorder.java b/core/src/main/java/hudson/logging/LogRecorder.java
index ab82ffdd55..09c7a69cd3 100644
--- a/core/src/main/java/hudson/logging/LogRecorder.java
+++ b/core/src/main/java/hudson/logging/LogRecorder.java
@@ -72,7 +72,6 @@ import java.util.logging.Logger;
 import javax.servlet.ServletException;
 import jenkins.security.MasterToSlaveCallable;
 import net.sf.json.JSONObject;
-import org.apache.commons.lang.StringUtils;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
 import org.kohsuke.stapler.DataBoundConstructor;
@@ -169,7 +168,7 @@ public class LogRecorder extends AbstractModelObject implements Saveable {
 
             String longerPrefix = null;
             for (int i = loggerNameParts.length; i > 0; i--) {
-                String loggerNamePrefix = StringUtils.join(Arrays.copyOf(loggerNameParts, i), ".");
+                String loggerNamePrefix = String.join(".", Arrays.copyOf(loggerNameParts, i));
                 seenPrefixes.put(loggerNamePrefix, seenPrefixes.getOrDefault(loggerNamePrefix, 0) + 1);
                 if (longerPrefix == null) {
                     relevantPrefixes.add(loggerNamePrefix); // actual logger name
diff --git a/core/src/main/java/hudson/model/ChoiceParameterDefinition.java b/core/src/main/java/hudson/model/ChoiceParameterDefinition.java
index 7d04e5c4b5..286d12505a 100644
--- a/core/src/main/java/hudson/model/ChoiceParameterDefinition.java
+++ b/core/src/main/java/hudson/model/ChoiceParameterDefinition.java
@@ -130,7 +130,7 @@ public class ChoiceParameterDefinition extends SimpleParameterDefinition {
     }
 
     public String getChoicesText() {
-        return StringUtils.join(choices, "\n");
+        return String.join("\n", choices);
     }
 
     @Override
diff --git a/core/src/main/java/hudson/model/Items.java b/core/src/main/java/hudson/model/Items.java
index 7811e68225..ddb33a4e85 100644
--- a/core/src/main/java/hudson/model/Items.java
+++ b/core/src/main/java/hudson/model/Items.java
@@ -278,7 +278,7 @@ public class Items {
             }
             name.push(p[i]);
         }
-        return StringUtils.join(name, '/');
+        return String.join("/", name);
     }
 
     /**
@@ -312,7 +312,7 @@ public class Items {
                 newValue.add(relativeName);
             }
         }
-        return StringUtils.join(newValue, ",");
+        return String.join(",", newValue);
     }
 
     // Had difficulty adapting the version in Functions to use no live items, so rewrote it:
diff --git a/core/src/main/java/hudson/model/View.java b/core/src/main/java/hudson/model/View.java
index 7347db0834..384034a8a9 100644
--- a/core/src/main/java/hudson/model/View.java
+++ b/core/src/main/java/hudson/model/View.java
@@ -1131,7 +1131,7 @@ public abstract class View extends AbstractModelObject implements AccessControll
                 metadata.put("iconClassName", iconClassName);
                 if (ctx != null) {
                     Icon icon = IconSet.icons
-                            .getIconByClassSpec(StringUtils.join(new String[]{iconClassName, iconStyle}, " "));
+                            .getIconByClassSpec(String.join(" ", iconClassName, iconStyle));
                     if (icon != null) {
                         metadata.put("iconQualifiedUrl", icon.getQualifiedUrl(ctx));
                     }
diff --git a/core/src/main/java/jenkins/model/queue/CompositeCauseOfBlockage.java b/core/src/main/java/jenkins/model/queue/CompositeCauseOfBlockage.java
index 9cb04c3bb7..b389d385bb 100644
--- a/core/src/main/java/jenkins/model/queue/CompositeCauseOfBlockage.java
+++ b/core/src/main/java/jenkins/model/queue/CompositeCauseOfBlockage.java
@@ -29,7 +29,6 @@ import hudson.model.queue.CauseOfBlockage;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
-import org.apache.commons.lang.StringUtils;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
 
@@ -50,7 +49,7 @@ public class CompositeCauseOfBlockage extends CauseOfBlockage {
 
     @Override
     public String getShortDescription() {
-        return StringUtils.join(uniqueReasons.keySet(), "; ");
+        return String.join("; ", uniqueReasons.keySet());
     }
 
     @Override
diff --git a/core/src/main/java/jenkins/tasks/filters/impl/RetainVariablesLocalRule.java b/core/src/main/java/jenkins/tasks/filters/impl/RetainVariablesLocalRule.java
index ee867332cf..4419a6e384 100644
--- a/core/src/main/java/jenkins/tasks/filters/impl/RetainVariablesLocalRule.java
+++ b/core/src/main/java/jenkins/tasks/filters/impl/RetainVariablesLocalRule.java
@@ -163,12 +163,12 @@ public class RetainVariablesLocalRule implements EnvVarsFilterLocalRule {
         }
 
         if (!variablesRemoved.isEmpty()) {
-            context.getTaskListener().getLogger().println(Messages.RetainVariablesLocalRule_RemovalMessage(getDescriptor().getDisplayName(), StringUtils.join(variablesRemoved.toArray(), ", ")));
+            context.getTaskListener().getLogger().println(Messages.RetainVariablesLocalRule_RemovalMessage(getDescriptor().getDisplayName(), String.join(", ", variablesRemoved)));
         }
         if (!variablesReset.isEmpty()) {
             // reset the variables using the initial value from System
             variablesReset.forEach(variableName -> envVars.put(variableName, systemEnvVars.get(variableName)));
-            context.getTaskListener().getLogger().println(Messages.RetainVariablesLocalRule_ResetMessage(getDescriptor().getDisplayName(), StringUtils.join(variablesReset.toArray(), ", ")));
+            context.getTaskListener().getLogger().println(Messages.RetainVariablesLocalRule_ResetMessage(getDescriptor().getDisplayName(), String.join(", ", variablesReset)));
         }
     }
 
diff --git a/test/src/test/java/jenkins/AgentProtocolTest.java b/test/src/test/java/jenkins/AgentProtocolTest.java
index 55925be2d5..ccfdbb9ad2 100644
--- a/test/src/test/java/jenkins/AgentProtocolTest.java
+++ b/test/src/test/java/jenkins/AgentProtocolTest.java
@@ -30,7 +30,6 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
 import jenkins.model.Jenkins;
-import org.apache.commons.lang.StringUtils;
 import org.junit.Rule;
 import org.junit.Test;
 import org.jvnet.hudson.test.Issue;
@@ -84,9 +83,9 @@ public class AgentProtocolTest {
         if (!failedChecks.isEmpty()) {
             String message = String.format("Protocol(s) are not %s: %s. %sEnabled protocols: %s",
                     shouldBeEnabled ? "enabled" : "disabled",
-                    StringUtils.join(failedChecks, ','),
+                    String.join(",", failedChecks),
                     why != null ? "Reason: " + why + ". " : "",
-                    StringUtils.join(agentProtocols, ','));
+                    String.join(",", agentProtocols));
             fail(message);
         }
     }