本次Java代写是一个有趣的任务，要求学生使用Java程序模拟一个包含捕食者/猎物的生态栖息系统（可以在水下，在丛林中，或在幻想世界中）。

This Java Writing Service is an interesting task that requires students to use Java programs to simulate an ecological habitat system that contains predators/prey (either underwater, in the jungle, or in a fantasy world).

4CCS1PPA Programming Practice and Applications

Your task is to extend a predator/prey simulation. You should use the foxes-and-rabbits-handout project (presented in the lecture, available for download from KEATS) as a basis for your own project, and modify and extend it to make it more interesting. Note that this is slightly different from the book project, so please use the version from KEATS, not from the book projects.

You must replace the Fox and Rabbit classes with different kinds of predator and prey to simulate a different habitat (for example, under water, in a jungle, or in a fantasy world). You may add additional classes to those included in the existing project.

This project is a pair programming task. You must work in pairs. Information about pair programming is provided separately. We will not accept submissions by individuals.

1 Core tasks

You should aim at completing all core tasks. They are as follows.

• Your simulation should have at least five different kinds of acting species. At least two of these should be predators (they eat another species), and at least two of them should not be predators (they may eat plants). Plants can either be assumed to always be available (as in the original project), or they can be simulated (see below).
• At least two predators should compete for the same food source.
• Some or all of the species should distinguish male and female individuals. For these, the creatures can only propagate when a male and female individual meet. (“Meet” means they need to be within a specified distance to each other, for example in a neighbouring cell.) You will need to experiment with the parameters for breeding probability to create a stable population.
• You should keep track of the time of day. At least some creatures should exhibit different behaviour at some time of the day (for example: they may sleep at night and not move during that time).

You should implement the core tasks first before you move on to the extension tasks.

2 Challenge tasks

Once you have finished the core tasks, implement one or more extension tasks. You can either choose from the following suggestions, or invent your own. You will be graded on a maximum of four extensions.

• Add plants. Plants grow at a given rate, but they do not move. Some creatures eat plants.They will die if they do not find their food plant.
• Add weather. Weather can change, and it influences the behaviour of some simulated aspects.
• For example, grass may not grow without rain, or predators cannot see well in fog.
• Add disease. Some animals are occasionally infected. Infection can spread to other animals when they meet.

If you invent your own extension tasks, check with your class supervisor before implementing them. You can get their comments to ensure they your idea is not too simple or too difficult.

To get full marks on this assignment you must demonstrate exceptional technical aptitude with the challenge tasks you implement.

3 Extra work — just for fun

You can extend the GUI (the graphical user interface) itself if you like, but no marks will be awarded for this work. If you do this — that’s good, but it is purely for fun and for your own practice.

4 Submission and Deadline

The submission consists of two parts: your code and a report documenting it.

The code

You have to submit a Jar of your project to the “Assignment 3: code submission” link in the assignment 3 section on the PPA KEATS page, before the due date. Your code will be assessed for:

• correct use of language constructs;
• commenting (is everything well-documented?);
• style (is the code nicely laid out and formatted, and are the variable names chosen well?);
• design (consideration given to cohesion, coupling, maintainability);
• challenge tasks (extra marks for technically impressive extensions).

The report

You also need to submit a written report that includes the following.

• A description of your simulation, including the types of species that you are simulating, their behaviour and interactions.
• A list and description of all extension tasks you have implemented.
• Known bugs or problems (Note: for a bug in your code that you document yourself, you may not lose many marks — maybe none, if it is in a challenge task. For bugs that we find that you did not document you will probably lose marks.)

The report must be submitted to the “Assignment 2: report submission” link in the assignment 2 section on the PPA KEATS page, before the deadline.

The report should be no more than four pages long.

Marking the assignment will involve an interview in your lab class. More detail about the interview will be provided separately.

The report must clearly state the names and student numbers of all students who worked on the submission.

The code and report must be submitted via the assignment 3 submission link on the PPA KEATS page, before the deadline, by both members of your pair. Both the source code and the report should clearly state the names of both authors.

5 Mark breakdown

The marks are distributed as follows:

• Report: 2 marks. However, if the report does not adequately describe your code you may lose marks on that part of your code as well. Not submitting a report will result in 0 marks for the entire submission.
• Base tasks 4 marks.
• Challenge tasks 10 marks.
• Commenting and style 4 marks.

6 Deadline

This assignment (code and report) is due Friday 22nd February, 17:00.