Due date: Monday, March 8, 2021.

In this homework you will write a Makefile for a Java project composed of several files.

Go to the folder week5 that you created for Lab 5 and Homework 5, and to the folder planets inside it. You have compiled these files manually for Homework 5. Now you'll write a Makefile for them.

Write a Makefile with the following features:

• Have a separate target for each class file. The list of dependencies should contain the source file that is being compiled and all the other source files for the classes used in that source file. Note that
  • The Earth class references the Sun class.
  • The Moon class references the Earth class.
  • The Main class references the Moon class.

  The compilation command for each object should be listed starting with a tab under that target.

  For example, to create a target for a compiled file called Earth.class based on compiling the source file earth.java, you have to look at the file Earth.java and see that it calls a method from the class Sun. Thus, the target will be listing both of them as dependencies:
  
  Earth.class: Earth.java Sun.java
        javac Earth.java

  Note: You'll have to manually replace the spaces at the beginning of the compilation command above with a tab.
  
  Proceed the same way for all of the others.
  
  

• Declare a variable called classes that contains the list of all the .class files. You can place it before all the targets. You will use it in the compilation command that creates the jar file and in the dependency list for it. For example, you can start with
  
  objects = Earth.class ...
  
  and replace the dots with the remaining objects, including the Main.
  
  
• Add a target for the jar file called planet.jar having all the class files as dependencies. Use the value of variable $(classes) in place of this list of classes. Write the appropriate compilation command below the target, using the variable again.
  
  
• Add a target called clean with no dependencies, having a command deleting all the .class files and the jar file.
  
  
• Add a default target at the top that redirects to the target planet.jar.
  
  
• Add a comment with your name at the top of the file.

Compile and execute the program using your Makefile. Then modify the file Main.java using any editor you want to print out an explanation message about what the program is doing. Place it before the one function call you'll find in the main. After that, recompile the program with the command make and run it again. Copy these commands and their outcome in a file called hw6.txt.

Upload to Canvas, Assignments, Homework 6:

• the file hw6.txt and
• the Makefile that you created for the homework (make sure it's not the one from the lab).