Sync Composite to Java 25: H6 file labels, fix console output typo, README mapping

02-structural/composite/Directory.java

@@ -1,53 +1,39 @@
 package composite;
-
 import java.util.ArrayList;
 import java.util.List;
-
 /**
- * Composite — a directory that can hold both Files (leaves)
- * and other Directories (composites).
+ * Composite — a directory that holds both Files (leaves) and other Directories.
+ *
+ * getSize() is recursive: asks each child for its size and sums them.
+ * print() recurses with deeper indentation.
  *
- * getSize() is recursive: it asks each child for its size and sums them.
  * The caller doesn't care whether a child is a File or Directory —
- * both implement FileSystemItem and answer getSize().
- *
- * This is the power of Composite: uniform treatment of simple and complex.
+ * both answer getSize() and print() the same way.
  */
 public class Directory implements FileSystemItem {
-
     private final String name;
     private final List<FileSystemItem> children = new ArrayList<>();
-
-    public Directory(String name) {
-        this.name = name;
-    }
-
+    public Directory(String name) { this.name = name; }
+    // Fluent add() — allows chaining: dir.add(file1).add(file2).add(subDir)
     public Directory add(FileSystemItem item) {
         children.add(item);
-        return this;  // fluent API for easy nesting
+        return this;
     }
-
-    public void remove(FileSystemItem item) {
-        children.remove(item);
-    }
-
-    @Override
-    public String getName() { return name; }
-
+    public void remove(FileSystemItem item) { children.remove(item); }
+    @Override public String getName() { return name; }
     @Override
     public long getSize() {
-        // Recursion: each child knows its own size.
-        // Files return their bytes; directories sum their children.
+        // Each child knows its own size: files return bytes, directories recurse.
+        // This is the Composite's core: uniform delegation down the tree.
         return children.stream()
                        .mapToLong(FileSystemItem::getSize)
                        .sum();
     }
-
     @Override
     public void print(String indent) {
         System.out.printf("%s[DIR]  %s/ (%,d bytes total)%n", indent, name, getSize());
         for (FileSystemItem child : children) {
-            child.print(indent + "    ");  // recurse with deeper indent
+            child.print(indent + "    ");  // each level indents 4 more spaces
         }
     }
 }