Massey University159.251 - Software Design and ConstructionAssignment 2 (Individual) 2019 (19%)DeadlinesYou must submit your final work using the stream submission system no later than Friday15 Nov. 2019 before 23:59. Please note that without an extension, submissions beyond thistime are not possible.You are expected to manage your source code, this includes making frequent backups. It isstrongly recommended (but not required) to use a private repository for this assignment.How to submit1. Upload a zip file consisting of:a. The Maven project folder (inc. pom.xml)b. performance-analysis.pdfc. coverage.pdf - the pdf version of the coverage report created by Maven2. upload this file to stream - note: the max upload size is set to 20 MB3. verify the submission: download the zip file, unzip it into a new folder and inspectcontent, run Maven from the command line, check the output including generated jarfilesTaskWork individually to create the following program in Java.Create a project assign251_2 using the Maven project layout, and within this project, createa project that implements custom appender and layout objects for Log4j. For this, you willneed to create an appender and layout that work with the other Log4j objects (i.e.implementing relevant Log4j abstract classes or interfaces), test them and run profiling toolson them to gauge their correctness and efficiency.Note there is no main class for this project, it will be run via your tests from sections 3 and 4.You may want to consider a test driven development methodology where your first step is tostart with section 3 and work backwards. This will allow you to check that your classes areworking correctly as you go.1. Implement a log4j appender assign251_2.MemAppender [6 marks]In this task, you will need to implement a custom log4j appender, which can be used directlywith the log4j logger. This MemAppender, unlike normal appenders, stores logs in memoryand prints them on demand. There is a limit to how many log events will be kept in memory(this should be configurable), and if the maximum is reached, the oldest logs should bedeleted.Implementation details:- It enforces the singleton pattern.- It stores the LoggingEvents in a list. This is supplied by dependency injection (note: ifyou have already created a default, that is okay).- It will need a layout. This will need to be able to be supplied when the MemAppenderis collected, and via the setLayout() method. If a layout is not supplied, and codecalling it is needed, appropriate precondition checks should be used (as some codemay not use the appender with the layout, so it is a valid option not to supply one, aslong as you don’t use any functionality that requires it).- There are three ways to get information about the LoggingEvents that it stores:a. Call the method getCurrentLogs() which will return an unmodifiable list ofthe LoggingEvents.b. Call the method getEventStrings() which will return an unmodifiable list ofstrings (generated using a layout stored in the MemAppender).c. Call the method printLogs() which will print the logging events to the consoleusing the layout and then clear the logs from its memory.- It has a property called maxSize, which needs to be configurable. When this size isreached, the oldest logs should be removed to make space for the new ones.- The number of discarded logs should be tracked, and can be accessed usinggetDiscardedLogCount(). This should be stored as a long type, as there may bemany discarded logs.Note: Be careful to observe the DRY principle - there are overlapping requirements above.3 marks Correct implementation of the singleton pattern and dependency injectionoptions for the list and layout.2 marks Correct implementation of the information printing / collection methods,along with sensible precondition checks where appropriate.1 mark Correct implementation of maxSize and associated features.2. a layout assign251_2.VelocityLa代写159.251、Python程序设计代做、代写Java，yout [3 marks]a. VelocityLayout basically works like PatternLayout, but uses Velocity as thetemplate engine. This layout should work with log4j appenders as well as theMemAppender.b. Variable to be supported:i. c (category)ii. d (date using the default toString() representation)iii. m (message)iv. p (priority)v. t (thread)vi. n (line separator)c. This means that the variable syntax is different, e.g. use $m instead of %md. VelocityLayout should have options to set its pattern both in the constructorand via a setter. An example string pattern could look like:“[$p] $c $d: $m”3. write tests that test your appender and layout in combination with differentloggers, levels and appenders [3 marks]a. Use JUnit5 for testing your appender and layout. Aim for good test coverageand precise asserts. [2 marks]b. Use the tests to show both the appender and layout working with differentcombinations of built in log4j classes as well as with each other. [1 mark]c. Tests should be stored in the appropriate locations according to the Mavenfolder structure.4. write tests to stress-test your appender/layout by creating a large amount oflog statements [5 marks]a. Create a separate test class for stress tests.b. Use these tests to compare the performance between MemAppender using aLinkedList, MemAppender using an ArrayList, ConsoleAppender andFileAppender - measure time and memory consumption (using JConsole orVisualVM or any profiler)c. Consider how to output your logs in such a way that makes comparisonsbetween the MemAppender and other appenders sensible.d. Use these scripts to compare the performance between PatternLayout andVelocityLayoute. Stress tests should test performance before and after maxSize has beenreached, and with different maxSize values.i. parameterised tests may be helpful here.f. Write a short report summarising your findings (embed screenshots ofmemory usage charts in this reports taken from VisualVM)g. The report name should be performance-analysis.pdfh. Measure your test coverage of the written tests by generating a branch andstatement coverage reports using Jacoco or Emma.Note that the marks for this section will be based around your reporting, the effectiveness ofyour stress tests in probing into the efficiency of the classes, and the overall integrationtesting, checking that these classes work in combination with other relevant out-of-the-boxclasses.5. write a Maven build script [2 marks]a. The Maven script should be used the build the project including compiling,testing, measuring test coverage, dependency analysis.b. Use the jacoco Maven plugin for measuring test coverage.Hints● You can use any development environment you prefer as it is a Maven project.● Library whitelist: only the following libraries and libraries they depend on can beused: Apache log4j, Apache Velocity, Guava, Apache Commons Collections, Jacocoand Emma.Penalties1. Code that is not self-documenting, or long or complex methods.2. Violating the Maven standard project layout or class names here3. Use of absolute paths (e.g., libraries should not be referenced using absolute pathslike “C:\\Users\\..”, instead use relative references w.r.t. the project root folder)4. References to local libraries (libraries should be referenced via the Maven repository)5. Use of libraries not on the whitelistBonus Question [2 marks]You can get 100% for the assignment without this. This will give you additional marks up tothe maximum if you lose some elsewhere.Create an MBean object for each instance of the MemAppender to add JMX monitoring tothis object, the properties to be monitored are:1. the log messages as array2. the estimated size of the cached logs (total characters)3. the number of logs that have been discardedPlagiarismWe will check submissions for plagiarism. Please read the Massey guidelines onplagiarism and dishonesty for details: https://goo.gl/S3tn18 .转自：http://www.3daixie.com/contents/11/3444.html
