Avoid this escape, and minor code clean up

config-application-package/src/main/java/com/yahoo/config/model/application/provider/AppSubDirs.java

@@ -11,7 +11,7 @@
  *
  * @author hmusum
  */
-public class AppSubDirs {
+public final class AppSubDirs {
 
     private final Tuple2<File, String> root;
     private final Tuple2<File, String> routingtables;

config-application-package/src/main/java/com/yahoo/config/model/application/provider/Bundle.java

@@ -4,9 +4,17 @@
 import com.yahoo.collections.Tuple2;
 import com.yahoo.vespa.config.util.ConfigUtils;
 
-import java.io.*;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.StringReader;
 import java.nio.charset.StandardCharsets;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.Objects;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.logging.Logger;
@@ -30,7 +38,7 @@ public class Bundle {
     public Bundle(JarFile jarFile, File bundleFile) {
         this.jarFile = jarFile;
         this.bundleFile = bundleFile;
-        defEntries = findDefEntries();
+        defEntries = List.copyOf(findDefEntries());
     }
 
     public static List<Bundle> getBundles(File bundleDir) {
@@ -56,11 +64,11 @@ private static List<File> getBundleFiles(File bundleDir) {
         if (!bundleDir.isDirectory()) {
             return new ArrayList<>();
         }
-        return List.of(bundleDir.listFiles((dir, name) -> name.endsWith(".jar")));
+        return List.of(Objects.requireNonNull(bundleDir.listFiles((dir, name) -> name.endsWith(".jar"))));
     }
 
     public List<DefEntry> getDefEntries() {
-        return Collections.unmodifiableList(defEntries);
+        return defEntries;
     }
 
     /**
@@ -93,18 +101,14 @@ private List<DefEntry> findDefEntries() {
         return defEntries;
     }
 
-    public JarFile getJarFile() {
-        return jarFile;
-    }
-
     public File getFile() {
         return bundleFile;
     }
 
     /**
      * Represents a def-file inside a Component. Immutable.
      */
-    public static class DefEntry {
+    public static final class DefEntry {
 
         private final Bundle bundle;
         private final ZipEntry zipEntry;
@@ -139,7 +143,7 @@ private String getNamespace() {
         }
 
         private String getContents() {
-            StringBuilder ret = new StringBuilder("");
+            StringBuilder ret = new StringBuilder();
             BufferedReader reader = new BufferedReader(getReader());
             try {
                 String str = reader.readLine();

tenant-cd-commons/src/main/java/ai/vespa/hosted/cd/commons/FeedClientBuilder.java

@@ -11,9 +11,9 @@
 /**
  * @author mortent
  */
-public class FeedClientBuilder extends FeedClientBuilderImpl {
+public final class FeedClientBuilder extends FeedClientBuilderImpl {
 
-    static AtomicReference<EndpointAuthenticator> endpointAuthenticator = new AtomicReference<>();
+    private static final AtomicReference<EndpointAuthenticator> endpointAuthenticator = new AtomicReference<>();
 
     public static void setEndpointAuthenticator(EndpointAuthenticator authenticator) {
         endpointAuthenticator.set(authenticator);