Use Java 11 methods where possible

bom/pom.xml

@@ -40,7 +40,8 @@ THE SOFTWARE.
   <properties>
     <asm.version>9.3</asm.version>
     <slf4jVersion>1.7.36</slf4jVersion>
-    <stapler.version>1685.v3b_5035c4ce05</stapler.version>
+    <!-- TODO https://github.com/jenkinsci/stapler/pull/377 -->
+    <stapler.version>1701.va_9519c27c7c2</stapler.version>
     <groovy.version>2.4.21</groovy.version>
   </properties>
 

cli/src/main/java/hudson/cli/CLI.java

@@ -47,7 +47,6 @@
 import java.security.KeyPair;
 import java.security.SecureRandom;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -267,7 +266,7 @@ public boolean verify(String s, SSLSession sslSession) {
         }
 
         if (args.isEmpty())
-            args = Collections.singletonList("help"); // default to help
+            args = List.of("help"); // default to help
 
         if (mode == null) {
             mode = Mode.HTTP;
@@ -346,7 +345,7 @@ class Authenticator extends ClientEndpointConfig.Configurator {
             @Override
             public void beforeRequest(Map<String, List<String>> headers) {
                 if (factory.authorization != null) {
-                    headers.put("Authorization", Collections.singletonList(factory.authorization));
+                    headers.put("Authorization", List.of(factory.authorization));
                 }
             }
         }

cli/src/main/java/hudson/cli/SSHCLI.java

@@ -35,7 +35,6 @@
 import java.net.URLConnection;
 import java.security.KeyPair;
 import java.security.PublicKey;
-import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 import java.util.logging.Level;
@@ -114,7 +113,7 @@ public boolean verifyServerKey(ClientSession clientSession, SocketAddress remote
                     WaitableFuture wf = channel.open();
                     wf.await();
 
-                    Set<ClientChannelEvent> waitMask = channel.waitFor(Collections.singletonList(ClientChannelEvent.CLOSED), 0L);
+                    Set<ClientChannelEvent> waitMask = channel.waitFor(List.of(ClientChannelEvent.CLOSED), 0L);
 
                     if (waitMask.contains(ClientChannelEvent.TIMEOUT)) {
                         throw new SocketTimeoutException("Failed to retrieve command result in time: " + command);

core/src/main/java/hudson/ClassicPluginStrategy.java

@@ -50,6 +50,7 @@
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.jar.Attributes;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
@@ -338,7 +339,7 @@ public <T> List<ExtensionComponent<T>> findComponents(Class<T> type, Hudson huds
         List<ExtensionFinder> finders;
         if (type == ExtensionFinder.class) {
             // Avoid infinite recursion of using ExtensionFinders to find ExtensionFinders
-            finders = Collections.singletonList(new ExtensionFinder.Sezpoz());
+            finders = List.of(new ExtensionFinder.Sezpoz());
         } else {
             finders = hudson.getExtensionList(ExtensionFinder.class);
         }
@@ -629,7 +630,7 @@ protected List<PluginWrapper> getEdges(PluginWrapper pw) {
                     for (Dependency d : dependencies) {
                         PluginWrapper p = pluginManager.getPlugin(d.shortName);
                         if (p != null && p.isActive())
-                            cgd.run(Collections.singleton(p));
+                            cgd.run(Set.of(p));
                     }
                 } catch (CycleDetectedException e) {
                     throw new AssertionError(e);    // such error should have been reported earlier

core/src/main/java/hudson/Functions.java

@@ -1945,7 +1945,7 @@ public boolean hyperlinkMatchesCurrentPage(String href) throws UnsupportedEncodi
     }
 
     public <T> List<T> singletonList(T t) {
-        return Collections.singletonList(t);
+        return List.of(t);
     }
 
     /**

core/src/main/java/hudson/PluginManager.java

@@ -930,7 +930,7 @@ public void dynamicLoad(File arc, boolean removeExisting, @CheckForNull List<Plu
                 if (batch != null) {
                     batch.add(p);
                 } else {
-                    start(Collections.singletonList(p));
+                    start(List.of(p));
                 }
 
             } catch (Exception e) {

core/src/main/java/hudson/PluginWrapper.java

@@ -222,7 +222,7 @@ public boolean hasDerivedDependencyErrors() {
      * The core can depend on a plugin if it is bundled. Sometimes it's the only thing that
      * depends on the plugin e.g. UI support library bundle plugin.
      */
-    private static Set<String> CORE_ONLY_DEPENDANT = Collections.singleton("jenkins-core");
+    private static Set<String> CORE_ONLY_DEPENDANT = Set.of("jenkins-core");
 
     /**
      * Set the list of components that depend on this plugin.

core/src/main/java/hudson/StructuredForm.java

@@ -67,7 +67,7 @@ public static List<JSONObject> toList(JSONObject parent, String propertyName) {
         if (v == null)
             return Collections.emptyList();
         if (v instanceof JSONObject)
-            return Collections.singletonList((JSONObject) v);
+            return List.of((JSONObject) v);
         if (v instanceof JSONArray)
             return (List) v;
 

core/src/main/java/hudson/WebAppMain.java

@@ -140,7 +140,7 @@ public void contextInitialized(ServletContextEvent event) {
         // Nicer console log formatting when using mvn jetty:run.
         if (Main.isDevelopmentMode && System.getProperty("java.util.logging.config.file") == null) {
             try {
-                Formatter formatter = (Formatter) Class.forName("io.jenkins.lib.support_log_formatter.SupportLogFormatter").newInstance();
+                Formatter formatter = (Formatter) Class.forName("io.jenkins.lib.support_log_formatter.SupportLogFormatter").getDeclaredConstructor().newInstance();
                 for (Handler h : Logger.getLogger("").getHandlers()) {
                     if (h instanceof ConsoleHandler) {
                         ((ConsoleHandler) h).setFormatter(formatter);

core/src/main/java/hudson/model/AbstractBuild.java

@@ -925,7 +925,7 @@ public boolean tearDown(AbstractBuild build, BuildListener listener) throws IOEx
     @Override
     @NonNull public List<ChangeLogSet<? extends ChangeLogSet.Entry>> getChangeSets() {
         ChangeLogSet<? extends ChangeLogSet.Entry> cs = getChangeSet();
-        return cs.isEmptySet() ? Collections.emptyList() : Collections.singletonList(cs);
+        return cs.isEmptySet() ? Collections.emptyList() : List.of(cs);
     }
 
     /**

core/src/main/java/hudson/model/Actionable.java

@@ -31,6 +31,7 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -227,7 +228,7 @@ public boolean removeAction(@Nullable Action a) {
             return false;
         }
         // CopyOnWriteArrayList does not support Iterator.remove, so need to do it this way:
-        return getActions().removeAll(Collections.singleton(a));
+        return getActions().removeAll(Set.of(a));
     }
 
     /**

core/src/main/java/hudson/model/Descriptor.java

@@ -59,13 +59,13 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -863,7 +863,7 @@ Permission getRequiredGlobalConfigPagePermission() {
     }
 
     private String getViewPage(Class<?> clazz, String pageName, String defaultValue) {
-        return getViewPage(clazz, Collections.singleton(pageName), defaultValue);
+        return getViewPage(clazz, Set.of(pageName), defaultValue);
     }
 
     private String getViewPage(Class<?> clazz, Collection<String> pageNames, String defaultValue) {
@@ -978,7 +978,7 @@ public void doHelp(StaplerRequest req, StaplerResponse rsp) throws IOException,
                 rsp.setContentType("text/html;charset=UTF-8");
                 try (InputStream in = url.openStream()) {
                     String literal = IOUtils.toString(in, StandardCharsets.UTF_8);
-                    rsp.getWriter().println(Util.replaceMacro(literal, Collections.singletonMap("rootURL", req.getContextPath())));
+                    rsp.getWriter().println(Util.replaceMacro(literal, Map.of("rootURL", req.getContextPath())));
                 }
                 return;
             }

core/src/main/java/hudson/model/DirectoryBrowserSupport.java

@@ -39,7 +39,6 @@
 import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Comparator;
 import java.util.GregorianCalendar;
 import java.util.LinkedHashMap;
@@ -764,7 +763,7 @@ private static List<List<Path>> buildChildPaths(VirtualFile cur, Locale locale)
                 for (VirtualFile f : files) {
                     Path p = new Path(Util.rawEncode(f.getName()), f.getName(), f.isDirectory(), f.length(), f.canRead(), f.lastModified());
                     if (!f.isDirectory()) {
-                        r.add(Collections.singletonList(p));
+                        r.add(List.of(p));
                     } else {
                         // find all empty intermediate directory
                         List<Path> l = new ArrayList<>();

core/src/main/java/hudson/model/JDK.java

@@ -197,7 +197,7 @@ public List<? extends ToolInstaller> getDefaultInstallers() {
                 Class<? extends ToolInstaller> jdkInstallerClass = Jenkins.get().getPluginManager()
                         .uberClassLoader.loadClass("hudson.tools.JDKInstaller").asSubclass(ToolInstaller.class);
                 Constructor<? extends ToolInstaller> constructor = jdkInstallerClass.getConstructor(String.class, boolean.class);
-                return Collections.singletonList(constructor.newInstance(null, false));
+                return List.of(constructor.newInstance(null, false));
             } catch (ClassNotFoundException e) {
                 return Collections.emptyList();
             } catch (Exception e) {

core/src/main/java/hudson/model/Job.java

@@ -81,6 +81,7 @@
 import java.util.GregorianCalendar;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.SortedMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -505,7 +506,7 @@ public void suggest(String token, List<SearchItem> result) {
 
     @Override
     public Collection<? extends Job> getAllJobs() {
-        return Collections.<Job>singleton(this);
+        return Set.of(this);
     }
 
     /**

core/src/main/java/hudson/model/JobProperty.java

@@ -36,6 +36,7 @@
 import java.io.IOException;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 import jenkins.model.Jenkins;
 import jenkins.model.OptionalJobProperty;
 import net.sf.json.JSONObject;
@@ -134,7 +135,7 @@ public Collection<? extends Action> getJobActions(J job) {
         // delegate to getJobAction (singular) for backward compatible behavior
         Action a = getJobAction(job);
         if (a == null)    return Collections.emptyList();
-        return Collections.singletonList(a);
+        return List.of(a);
     }
 
 //

core/src/main/java/hudson/model/ListView.java

@@ -143,7 +143,7 @@ protected Object readResolve() {
                 includePattern = Pattern.compile(includeRegex);
             } catch (PatternSyntaxException x) {
                 includeRegex = null;
-                OldDataMonitor.report(this, Collections.singleton(x));
+                OldDataMonitor.report(this, Set.of(x));
             }
         }
         synchronized (this) {

core/src/main/java/hudson/model/ParametersDefinitionProperty.java

@@ -39,8 +39,8 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import javax.servlet.ServletException;
 import jenkins.model.Jenkins;
@@ -112,7 +112,7 @@ public List<String> getParameterDefinitionNames() {
     @NonNull
     @Override
     public Collection<Action> getJobActions(Job<?, ?> job) {
-        return Collections.singleton(this);
+        return Set.of(this);
     }
 
     @Deprecated

core/src/main/java/hudson/model/Queue.java

@@ -1987,7 +1987,7 @@ default boolean isConcurrentBuild() {
          * @since 1.377
          */
         default Collection<? extends SubTask> getSubTasks() {
-            return Collections.singleton(this);
+            return Set.of(this);
         }
 
         /**

core/src/main/java/hudson/model/Slave.java

@@ -59,10 +59,7 @@
 import java.net.URL;
 import java.net.URLConnection;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.jar.JarFile;
@@ -744,5 +741,5 @@ private Object readResolve() {
     /**
      * Provides a collection of file names, which are accessible via /jnlpJars link.
      */
-    private static final Set<String> ALLOWED_JNLPJARS_FILES = Collections.unmodifiableSet(new HashSet<>(Arrays.asList("agent.jar", "slave.jar", "remoting.jar", "jenkins-cli.jar", "hudson-cli.jar")));
+    private static final Set<String> ALLOWED_JNLPJARS_FILES = Set.of("agent.jar", "slave.jar", "remoting.jar", "jenkins-cli.jar", "hudson-cli.jar");
 }

core/src/main/java/hudson/model/User.java

@@ -441,7 +441,7 @@ private LegitimateButUnknownUserDetails(String username) throws IllegalArgumentE
             super(
                     username, "",
                     true, true, true, true,
-                    Collections.singleton(SecurityRealm.AUTHENTICATED_AUTHORITY2)
+                    Set.of(SecurityRealm.AUTHENTICATED_AUTHORITY2)
             );
         }
     }

core/src/main/java/hudson/model/labels/LabelAtom.java

@@ -170,7 +170,7 @@ public <V, P> V accept(LabelVisitor<V, P> visitor, P param) {
 
     @Override
     public Set<LabelAtom> listAtoms() {
-        return Collections.singleton(this);
+        return Set.of(this);
     }
 
     @Override

core/src/main/java/hudson/scm/EditType.java

@@ -24,8 +24,6 @@
 
 package hudson.scm;
 
-import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import org.kohsuke.stapler.export.CustomExportedBean;
 
@@ -60,5 +58,5 @@ public String toExportedObject() {
     public static final EditType EDIT = new EditType("edit", "The file was modified");
     public static final EditType DELETE = new EditType("delete", "The file was removed");
 
-    public static final List<EditType> ALL = Collections.unmodifiableList(Arrays.asList(ADD, EDIT, DELETE));
+    public static final List<EditType> ALL = List.of(ADD, EDIT, DELETE);
 }

core/src/main/java/hudson/security/HudsonPrivateSecurityRealm.java

@@ -56,6 +56,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Random;
+import java.util.Set;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -586,7 +587,7 @@ public User getUser(String id) {
     }
 
     // TODO
-    private static final Collection<? extends GrantedAuthority> TEST_AUTHORITY = Collections.singleton(AUTHENTICATED_AUTHORITY2);
+    private static final Collection<? extends GrantedAuthority> TEST_AUTHORITY = Set.of(AUTHENTICATED_AUTHORITY2);
 
     public static final class SignupInfo {
         public String username, password1, password2, fullname, email, captcha;

core/src/main/java/hudson/security/LegacyAuthorizationStrategy.java

@@ -28,7 +28,7 @@
 import hudson.Extension;
 import hudson.model.Descriptor;
 import java.util.Collection;
-import java.util.Collections;
+import java.util.Set;
 import jenkins.model.Jenkins;
 import org.acegisecurity.acls.sid.GrantedAuthoritySid;
 import org.jenkinsci.Symbol;
@@ -55,7 +55,7 @@ public ACL getRootACL() {
 
     @Override
     public Collection<String> getGroups() {
-        return Collections.singleton("admin");
+        return Set.of("admin");
     }
 
     @Extension @Symbol("legacy")

core/src/main/java/hudson/security/Permission.java

@@ -27,10 +27,8 @@
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.model.Hudson;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -150,7 +148,7 @@ public Permission(@NonNull PermissionGroup group, @NonNull String name,
         this.description = description;
         this.impliedBy = impliedBy;
         this.enabled = enable;
-        this.scopes = Collections.unmodifiableSet(new HashSet<>(Arrays.asList(scopes)));
+        this.scopes = Set.of(scopes);
         this.id = owner.getName() + '.' + name;
 
         group.add(this);