Recursive Structures Lab

Introduction

The goal of this lab is to practice using recursion to interact with recursively structured data. One example of a recursively structured collection is the file system of a computer. A file system is made up of directories, each of which may contain additional directories, and so forth.

Please watch this 6-minute video by Gayle Laakmann McDowell :

Source Files

The following files are provided:

1. DirectorySearcher.java – This (unfinished) class is responsible for recursively traversing a directory tree starting from a designated directory.
2. DirectoryDriver.java – This is a driver class for executing the methods provided by DirectorySearcher. As currently written, the main method uses a DirectorySearcher to list the contents of the current directory.

Instructions

1. Download and test the two files above. Make sure you understand how the existing code works.
2. Complete the listDirectories (plural) method of the DirectorySearcher class. Test your method by modifying the driver so that it calls this method instead of listDirectory (singular).
   • Your solution should print a "/" after each directory name and indent the files under each directory. For example, if the starting path is "../P5", the output might look like this:

     P5/
         Beetle.class
         Pose.java
         SwarmConstants.java
         StdDraw.java
         Actor.class
         StdDraw$RetinaImageIcon.class
         Point.java
         Bee.java
         beetles.txt
         Swarm.class
         Actor.java
         Insect.class
         Simulation.class
         .checkstyle
         all_examples.txt
         Beetle.java
         Flower.class
         Swarm.java
         SwarmConstants.class
         PoseUtils.class
         PoseUtils.java
         Simulation.java
         Pose.class
         Bee.class
         .settings/
             org.eclipse.jdt.core.prefs
         SwarmDriver.class
         StdDraw.class
         swarm.txt
         flowers.txt
         bees.txt
         interesting.txt
         SwarmDriver.java
         .classpath
         .project
         Insect.java
         Point.class
         Flower.java
     

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3. Complete the searchDirectories method of the DirectorySearcher class. Test your method by modifying the driver; search for different patterns to make sure it works.
   • Your solution should print the path to each file that is found. (Just print the File object itself, rather than calling getName.) For example, if the search string is "se", the output might look like this:

     ../P5/Pose.java
     ../P5/Insect.class
     ../P5/PoseUtils.class
     ../P5/PoseUtils.java
     ../P5/Pose.class
     ../P5/.settings
     ../P5/.settings/org.eclipse.jdt.core.prefs
     ../P5/Insect.java
     

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4. Submit your completed DirectorySearcher.java file via GradeScope.