In memory file system implementation using Java

filesystem_Directory.java

package oop.filesystem;

import java.util.Set;
import java.util.TreeSet;

/**
 * @author Bazlur Rahman Rokon
 * @since 3/31/17.
 */
public class Directory extends Node {
    private Set<Node> nodes;

    public Directory(String path) {
        super(path);
        nodes = new TreeSet<>();
    }

    public void add(Node node) {
        node.setRoot(this);
        nodes.add(node);
    }

    public Set<Node> getNodes() {
        return nodes;
    }

    @Override
    public long getLength() {
        long length = 0;
        for (Node node : nodes) {
            length += node.getLength();
        }
        return length;
    }

    public void printTree() {
        int indent = 0;
        StringBuilder sb = new StringBuilder();
        printDirectoryTree(this, indent, sb);
        System.out.println(sb.toString());
    }

    private void printDirectoryTree(Node node, int indent, StringBuilder sb) {
        sb.append(getIndentString(indent));
        sb.append("+--");
        sb.append(node.getName());
        sb.append("/");
        sb.append("\n");

        if (node.isDirectory()) {
            Directory directory = (Directory) node;
            for (Node file : directory.getNodes()) {
                printDirectoryTree(file, indent + 1, sb);
            }
        }
    }

    private static String getIndentString(int indent) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < indent; i++) {
            sb.append("|  ");
        }
        return sb.toString();
    }
}

filesystem_File.java

package oop.filesystem;

/**
 * @author Bazlur Rahman Rokon
 * @since 3/31/17.
 */
public class File extends Node {
    private String content; /// for simplicity

    public File(String name, String content) {
        super(name);
        this.content = content;
    }

    public File(String name) {
        super(name);
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    @Override
    public long getLength() {
        if (content != null) {
            return content.getBytes().length;
        }

        return 0;
    }
}

filesystem_Main.java

package oop.filesystem;

/**
 * @author Bazlur Rahman Rokon
 * @since 3/31/17.
 */
public class Main {
    public static void main(String[] args) {

        Directory root = new Directory("root");
        File file = new File("profile.jpg");
        root.add(file);

        Directory movie = new Directory("movie");
        root.add(movie);

        Directory englishMovie = new Directory("english");

        englishMovie.add(new File("IronFist.mp4"));
        englishMovie.add(new File("The Shawshank Redemption.mp4"));
        englishMovie.add(new File("ZotaPia.mp4"));
        File despicableMe = new File("DespicableMe.mp4");
        englishMovie.add(despicableMe);
        movie.add(englishMovie);

        Directory banglaMovie = new Directory("Bangla");
        banglaMovie.add(new File("The Clay Bird.mp4"));
        banglaMovie.add(new File("Jibon Thekey Neya.mp4"));

        movie.add(banglaMovie);

        root.printTree();

        System.out.println("name: " + movie.getName());
        System.out.println("Created: " + movie.getCreated());
    }
}

filesystem_Node.java

package oop.filesystem;

import java.time.LocalDateTime;

/**
 * @author Bazlur Rahman Rokon
 * @since 3/31/17.
 */
public abstract class Node implements Comparable<Node> {
    private Directory root;
    private String name;
    private LocalDateTime created;
    private LocalDateTime lastUpdated;
    private LocalDateTime lastAccessed;

    public Node(String name) {
        this.name = name;
        this.created = LocalDateTime.now();
        this.lastUpdated = LocalDateTime.now();
        this.lastAccessed = LocalDateTime.now();
    }

    public boolean isDirectory() {

        return this instanceof Directory;
    }

    public String getPath() {

        return root != null ? root.getPath() + "/" + name : name;
    }

    public Node getParent() {
        return root;
    }

    public abstract long getLength();

    public String getName() {
        return name;
    }

    @Override
    public int compareTo(Node o) {

        return this.getName().compareTo(o.getName());
    }

    public void setRoot(Directory root) {
        this.root = root;
    }

    public LocalDateTime getCreated() {
        return created;
    }

    public LocalDateTime getLastUpdated() {
        return lastUpdated;
    }

    public LocalDateTime getLastAccessed() {
        return lastAccessed;
    }

    @Override
    public String toString() {
        return "root=" + root +
                ", \nname='" + name + '\'' +
                ", \ncreated=" + created +
                ", \nlastUpdated=" + lastUpdated +
                ", \nlastAccessed=" + lastAccessed;

    }
}