Chain of responsibility and template method design patterns

This exercise will test your knowledge of the chain of responsibility and template method design patterns. SET-UP Import the Netbeans project folder named 'AJP-P4-2012-2013-STUDENT'. Open it up. You have been given a set of unit tests. Initially, there will be LOTS of syntax errors in these unit tests. This is expected. The errors will disappear as you write the required classes.
INSTRUCTIONS FOR BRONZE TASK In the src folder of your new project, in the package named uk.ac.tees.bronze.username, create a file called Malfunction.java. This class represents a malfunction on a spaceship. Your class should satisfy the following criteria. • The Malfunction class should have a severity instance variable that records the severity of the problem. • The different levels of problem on a spaceship are as follows – TRIVIAL, LOW, MEDIUM and HIGH. These should be defined in a separate enum called Severity.java. • The Malfunction class should also have a description instance variable that stores a textual description of the problem. This variable should be of type String. • The constructor for the Malfunction class should be Malfunction(Severity severity, String description). Null and empty descriptions should be caught and converted into the default description - “No description available. Probably serious”. • You should write accessor methods for the description and severity instance variables. Next, create a new interface called MalfunctionHandler.java. This interface should define the following two methods: public void processMalfunction(Malfunction malfunction); public void setNextHandler(MalfunctionHandler next); Now implement this interface in 4 concrete classes, named as follows: • SpaceMonkey.java • ServiceRobot.java • Engineer.java • Captain.java Each of the classes above should have a constructor that takes a Severity parameter. This parameter is the competence level of the crew member. A crew member can handle problems up to (and including) their own competence level. For example, new Engineer(Severity.MEDIUM) creates an Engineer object that can deal with anything up to (and including) medium severity problems.
Inside each of these 4 classes, the processMalfunction(Malfunction) method should function like this:
IF   severity   of   malfunction   is   equal   to   or   below   my   level   of   my  competence WRITE the problem description to the log file WRITE “­­­ XXX assigned to problem.\n\n” to the log file ELSE Pass the malfunction to superior officer (the next element in the  chain) END IF *where XXX is the type of handler e.g. Space Monkey, and the log file is  'log­bronze.txt' I have given you a utility class called FileUtility.java to simplify the process of writing to the log file. Complete your solution so that it demonstrates the Chain of Responsibility pattern. The unit tests I have provided will guide your solution. Note that the expected result for this task can be found in expected-bronze.txt' which is in the root folder of your project. Make sure that your solution to the BRONZE task does not have any CheckStyle errors. You cannot pass this task if your code contains CheckStyle errors.
INSTRUCTIONS FOR SILVER TASK In the src folder of your new project, in the package named uk.ac.tees.silver.username, modify your solution to the previous task so that: • MalfunctionHandler is now defined as an abstract class containing the instance variables severity and description • MalfunctionHandler should also define an instance variable f, a File object that refers to the log file log-silver.txt. • In this class, change the processMalfunction(Malfunction) method from abstract to final protected. The method should function like this:
IF severity of malfunction is equal to or below my level of my  competence handleProblem() ELSE Pass the malfunction to superior officer (the next element in  the chain) END IF
• In MalfunctionHandler, define a new abstract method called handleProblem() • Change the 4 concrete handler classes so that they extend MalfunctionHandler.
• The constructors in the concrete classes should call the superconstructor. • Implement the handleProblem() method in each class to achieve the output listed in expected-silver.txt. The unit tests I have provided will guide your solution. Note that the expected result for this task can be found in expected-silver.txt' which is in the root folder of your project. Make sure that your solution to the SILVER task does not have any CheckStyle errors. You cannot pass this task if your code contains CheckStyle errors.
INSTRUCTIONS FOR GOLD TASK In the src folder of your new project, in the package named uk.ac.tees.gold.username, create a new file called Bot.java. This class represents a robot used to explore Mars. The Bot class should • Be an abstract class • Should declare an instance variable called identifier of String type. This will hold the unique serial number of the robot. • Should declare an instance variable called f, a reference to the File where the bot will write log entries. This should be set to log-gold.txt. • The constructor will initialise the identifier field. • The Bot class will also define a checkEnvironment() method, that always returns true • Should declare a method called powerUp() that writes the following to the log file: <ID: Powering up. • Should declare a method called powerDown() that writes the following to the log file: <ID: Powering down. • The Bot class should declare an abstract method called doTask() • The Bot class should declare a template method called executeTask() that does the following if ( checkEnvironment ) { powerUp() doTask() powerDown() } • The Bot class should be extended by DiggerBot, ScannerBot and AerialBot • The constructors of these sub-classes should call the superconstructor. • Each of the sub-classes should implement the doTask() method • When the DiggerBot is told to executeTask(), it will write the following to the log file: <ID: Burrowing through the Martian regolith.
• When the ScannerBot is told to executeTask(), it will write the following to the log file: <ID: Scanning local terrain for water. • When the AerialBot is told to executeTask(), it will write the following to the log file: <ID: Flying through the thin Martian atmosphere. • Now modify the checkEnvironment() method in AerialBot to prevent an AerielBot flying during a Martian dust storm i.e. the checkEnvironment() method will return false when Environment.dustStorm=true. • Now modify the checkEnvironment() method in ScannerBot to prevent a ScannerBot from working if radiation levels exceed MEDIUM i.e. the checkEnvironment() will return false when Environment.RadiationLevel MEDIUM The unit tests I have provided will guide your solution. Note that the expected result for this task can be found in expected-gold.txt and expected-gold2.txt which are in the root folder of your project. Make sure that your solution to the GOLD task does not have any CheckStyle errors. You cannot pass this task if your code contains CheckStyle errors.