Add another example of composite pattern

Design Patterns/src/composite/file/directories/Directory.java

@@ -0,0 +1,80 @@
+package composite.file.directories;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Directory extends File {
+
+    private final List<File> files = new ArrayList<>();
+    private final String name;
+    private final String dateModified;
+    private final Long size;
+
+    Directory(String name, String dateModified, Long size) {
+        this.name = name;
+        this.dateModified = dateModified;
+        this.size = size;
+    }
+
+    FileIterator createIterator() {
+        return new FileIterator(files);
+    }
+
+    @Override
+    String getName() {
+        return name;
+    }
+
+    @Override
+    String getDateModified() {
+        return dateModified;
+    }
+
+    @Override
+    Long getSize() {
+        return size;
+    }
+
+    @Override
+    void add(File file) {
+        files.add(file);
+    }
+
+    @Override
+    void remove(File file) {
+        files.remove(file);
+    }
+
+    @Override
+    File getFile(int fileIndex) {
+        return files.get(fileIndex);
+    }
+
+    @Override
+    void displayFileInfo() {
+        System.out.println(
+                "\n\nFolder Name: " + getName() +
+                "\nDate Modified: " + getDateModified() +
+                "\nSize: " + getSize() +
+                "\nContents:"
+        );
+
+        FileIterator fileIterator = createIterator();
+        while (fileIterator.hasNext()) {
+            File file = fileIterator.next();
+            file.displayFileInfo();
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "\n\nFolder Name: " + name +
+                "\nDate Modified: " + dateModified +
+                "\nSize: " + size +
+                "\nContents{" + files +
+                ", name='" + name + '\'' +
+                ", dateModified='" + dateModified + '\'' +
+                ", size=" + size +
+                "}";
+    }
+}

Design Patterns/src/composite/file/directories/File.java

@@ -0,0 +1,15 @@
+package composite.file.directories;
+
+public abstract class File {
+
+    void add(File file) { throw new UnsupportedOperationException(); }
+    void remove(File file) { throw new UnsupportedOperationException(); }
+    File getFile(int fileIndex) { throw new UnsupportedOperationException(); }
+    void displayFileInfo() { throw new UnsupportedOperationException(); }
+
+    String getName() { throw new UnsupportedOperationException(); }
+    String getDateModified() { throw new UnsupportedOperationException(); }
+    Long getSize() { throw new UnsupportedOperationException(); }
+    String getExtension() { throw new UnsupportedOperationException(); }
+
+}

Design Patterns/src/composite/file/directories/FileIterator.java

@@ -0,0 +1,27 @@
+package composite.file.directories;
+
+import java.util.Iterator;
+import java.util.List;
+
+public class FileIterator implements Iterator<File> {
+
+    private final List<File> directory;
+    private int currentIndex = 0;
+
+    public FileIterator(List<File> directory) {
+        this.directory = directory;
+    }
+
+    @Override
+    public boolean hasNext() {
+        return currentIndex < directory.size();
+    }
+
+    @Override
+    public File next() {
+        if (this.hasNext()) {
+            return directory.get(currentIndex++);
+        }
+        return null;
+    }
+}

Design Patterns/src/composite/file/directories/Main.java

@@ -0,0 +1,28 @@
+package composite.file.directories;
+
+public class Main {
+    public static void main(String[] args) {
+
+        File rootDirectory = new Directory("Root", "27/02/2021", 100L);
+
+        rootDirectory.add(new TxtFile("Winston", "26/05/2019", 5L));
+        rootDirectory.add(new TxtFile("Readme", "06/02/2019", 202L));
+
+        File goudhamFolder = new Directory("Goudham", "12/03/2018", 150L);
+
+        goudhamFolder.add(new TxtFile("University", "07/08/2002", 90L));
+        goudhamFolder.add(new TxtFile("Overwatch", "02/12/2010", 678L));
+
+        rootDirectory.add(goudhamFolder);
+
+        File matthewFolder = new Directory("Matthew", "05/10/2019", 570L);
+
+        matthewFolder.add(new TxtFile("Grades", "10/03/2000", 700L));
+        matthewFolder.add(new TxtFile("Star Wars", "18/08/2016", 20L));
+
+        rootDirectory.add(matthewFolder);
+
+        rootDirectory.displayFileInfo();
+
+    }
+}

Design Patterns/src/composite/file/directories/TxtFile.java

@@ -0,0 +1,48 @@
+package composite.file.directories;
+
+public class TxtFile extends File {
+
+    private final String name;
+    private final String dateModified;
+    private final Long size;
+    private final String extension = ".txt";
+
+    public TxtFile(String name, String dateModified, Long size) {
+        this.name = name;
+        this.dateModified = dateModified;
+        this.size = size;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String getDateModified() {
+        return dateModified;
+    }
+
+    @Override
+    public Long getSize() {
+        return size;
+    }
+
+    @Override
+    public String getExtension() {
+        return extension;
+    }
+
+    @Override
+    public void displayFileInfo(){ System.out.println(this); }
+
+    @Override
+    public String toString() {
+        return "TxtFile{" +
+                "name='" + name + '\'' +
+                ", dateModified='" + dateModified + '\'' +
+                ", size=" + size +
+                ", extension='" + extension + '\'' +
+                "} ";
+    }
+}