Added the first version of a program that prints a

directory tree

PrintDirectoryTree.java

@@ -0,0 +1,77 @@
+//Java/JavaTutorials/PrintDirectoryTree.java
+//Matthew Ellison
+// Created: 01-07-2020
+//Modified: 01-07-2020
+//This class will step through a directory and print out the contents
+
+//TODO: I am still learning what exactly this code does. I need to insert some comments as soon as I learn what everything is doing.
+
+
+import java.util.EnumSet;
+import java.io.*;
+import java.nio.file.*;
+import java.nio.file.attribute.*;
+import static java.nio.file.FileVisitResult.*;
+
+
+public class PrintDirectoryTree{
+	public static void main(String[] args) throws IOException{
+		String searchDirectory = "";	//This string holds the directory that will be printed
+
+		//This makes sure something is set for the directory
+		if(args.length == 1){
+			//Set the argument as the directory
+			searchDirectory = args[0];
+		}
+		else if(args.length == 0){
+			//Set the entire C drive as the directory if none was given
+			searchDirectory = "C:/";
+		}
+		else{
+			//Print an error and exit if there are mutliple arguments sent
+			System.out.print("There are too many parameters!");
+			return;
+		}
+
+		try{
+			Path startingDir = Paths.get(searchDirectory);
+			EnumSet<FileVisitOption> opts = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
+			PrintTree pf = new PrintTree();
+			Files.walkFileTree(startingDir, opts, Integer.MAX_VALUE, pf);
+		}
+		catch(Exception x){
+			System.err.print("Exception raised: " + x);
+		}
+	}
+	public static class PrintTree extends SimpleFileVisitor<Path>{
+		@Override
+		public FileVisitResult visitFile(Path file, BasicFileAttributes attr){
+			//This prints out a particular string when a certain type of file is found
+			if(attr.isSymbolicLink()){
+				System.out.format("Symbolic Link: %s", file);
+			}
+			else if(attr.isRegularFile()){
+				System.out.format("Real File: %s", file);
+			}
+			else{
+				System.out.format("Other: %s", file);
+			}
+
+			//This prints out the size of any given file
+			System.out.println("(" + attr.size() + " bytes)");
+			return CONTINUE;
+		}
+		@Override
+		public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs){
+			//This simply prints out the name of the directory
+			System.out.format("Directory: %s\n", dir);
+			return CONTINUE;
+		}
+		@Override
+		public FileVisitResult visitFileFailed(Path file, IOException exc){
+			//This prints out whatever error message was thrown
+			System.err.println(exc);
+			return CONTINUE;
+		}
+	}
+}