Writing a Java application with Swing components
You are asked to write a Java application to manipulate entries in a text file. The program must have a Graphical User Interface using Swing components.
Choose a meaningful interpretation for the entries stored in your file. They might be names and addresses, or titles and bibliographic information, or something more imaginative. Each file entry should consist of a "key" string (e.g. a person's name or ID, a book's author or ISBN, etc) and one or more strings representing associated data fields. You may choose to lay out these fields in your text file on consecutive lines, e.g.
key data1 data2 key data1 data2 ...
Your program should be able to read the whole text file and store all entries in internal data structures of your design. One convenient possibility may be to store the keys in a javax.swing.DefaultListModel and to store the data fields in objects stored in a java.util.HashMap. The program should also be able to save the modified data structures back to the text file in the original format.
The graphical user interface should have at least
- A scrollable list component for selecting entries. The list should display the key strings for your file entries.
- Text fields and/or text areas for displaying, entering and modifying data fields in your file entries.
- Buttons to add and delete entries, and a means of modifying existing entries.
Development Platform
You may be able to develop and run your Swing-based program on sirah or the other course hosts. However this is only likely to work if you are logging in from a computer that can display remote X-Windows based applications--perhaps a UNIX workstation or a PC running Hummingbird Exceed. Even then you may still have problems displaying the remote graphical application if there is a firewall between you and sirah.So in general I recommend you develop your GUI application locally on your PC or workstation instead. If necessary (and allowed), you can download Java software from SDK 1.2 or SDK 1.3. Please let me know if this is impractical for you. I will accept software developed with any version of Java that includes the Swing set.
Submission of your Homework
Your submission should consist of files including- A description of your program and the format of your data file, preferably in Microsoft Word, HTML, or plain text format,
- all Java source code, and
- an example data file.
On sirah you will find a directory called /home/project/it1spring01/homework2/uid where uid is your login ID. To submit Assignment 2, please copy your files into this directory.
Grading
For this assignment, there will be a total of 20 points. Grading criteria are similar to Assignment 1. Some points will be assigned on the basis of apparent effort and uniqueness, and on the extent to which your application presents an attractive and intuitive GUI.
Useful resources
Simple Swing examples
You will find most of the Swing components you are likely to need illustrated in the examples from the lectures.Simple reading and writing of text files
Since this wasn't covered in class, there is an example that reads lines in a text file, and writes them back to another text file, in here.Simple use of collection classes
I have added a few extra slides on Vector and Hashmap to the online lectures on the Java language. See slides 71 to 76.The Standard API classes
Including Swing, see the Java 2 API specification.@ 1.2 log @Modified Files: hw1.html hw2.html @ text @d66 1 a66 1 sirah or the other course hosts. This is only likely d69 1 a69 1 a PC running Hummingbird Exceed (and even then d71 1 a71 1 if there is a firewall between you and sirah). d73 2 a74 2 In general I recommend you develop GUI applications locally on your PC or workstation. d117 1 a117 1
The Standard API classes
d119 4 a122 3 Including Swing, see the Java 2 API specification. d130 7 a136 1Simple Swing examples
d138 3 a140 4 You will find most of the Swing components you are likely to need illustrated in the examples from the lectures. @ 1.1 log @*** empty log message *** @ text @d3 2 a4 1CIS 6930-01
Fall 2000
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Assignment #2
d14 1 a16 78Writing a Java application with class structure
There are two types of Java programs: applications and applets. An applet is a web-based Java program embedded in an HTML document. An application, on the other hand, is not web-based. It is developed and run at the command line, much like a C program.Your first Java programming assignment is to write an application that uses a class. The goal is to start by giving you some practice with Java syntax and making sure that you understand the class concept.
Before starting this assignment, you should should become familiar with the Java programming environment on sirah.
You may also use Java compilers on other systems if your prefer, or a programming environment such as J++ or Cafe'. But if you use a programming environment, do not use it to generate code for you. Also see the tutorial materials for links to download an editor such as JavaEdit or TextPad for use on a PC.
Writing the programs
Choose one of the following two sets of programs to write.
Choice 1: Writing and Testing a class Candy
Design and implement a class to represent pieces of candy. There will be three instance variables to represent properties of the candy:
- String shape; // this may take values such as "square", "round" or "blob".
- Color c;
- String flavor; // values such as "vanilla", "chocolate", or "yuck".
Write a constructor method that takes three arguments that are used as values to initialize the instance variables.
You should also write the following public methods.
- three "set" methods - one to assign each instance variable
- either three "get" methods to return the values of the instance variables, or a method called "toString" that returns a string describing the three properties of the candy.
- a method called "combine" which takes two arguments of type Candy and returns a result of type Candy. This method should combine the properties of the two arguments to return a new third candy. You can decide how to combine them. For combining shapes and flavors, you can arbitrarily pick a result shape and flavor, and in at least one case you should refuse to combine incompatible shapes and flavors by returning an exception. For combining colors, you could average together the red, blue and green values of the two colors. (Check the API Color class to see how to find out the RBG values of a Color.)
- You may design additional methods if needed by your test application program below.
You must also write a test program for this class:
Design an application that prompts the user to type in the shape, color, and flavor of at least two pieces of candy. Create an instance of the Candy class for each one. Combine the two pieces to get a third piece of candy and either use the "get" methods or the "toString" method to print out a description of the result.
Show a couple of runs of the program. Be sure to demonstrate a case of successfully combining candies and also one which doesn't because the combine gives an Exception. d18 1 a18 1
a19 8 Choice 2: Writing and Testing a class DataSets
Design and implement a class to represent a set of data, that is a number of experimental numbers representing some value. You will need an instance variable to keep the data:
- double [ ] data;
where the notation "sigma x" is to be interpreted as summing all the elements of the array and the notation "sigma x squared" means to first square each element of the array and then sum them.
You must also write a test program for this class.
Design an application that prompts the user to type in at least two sets of double values. Create an instance of the DataSet class for each one. Compute the mean and standard deviation of each dataset and print the results. Then combine the two DataSets to get a third one and print out its mean and standard deviation.
Show a couple of runs of the program. In a case where you refuse to combine some datasets, be sure to demonstrate that part.
a135 32 What to put on the homework page as the submission of your homework
Submit your assignment by linking the description of your program, a link to the Java source code and a small file showing sample output run (like my .run files) to your homework page.
For how to write a description of your homework and document your program, and other information, please see these homework guidelines.
Grading
For this assignment, there will be a total of 15 points. These will be separated into partial points of 5 and 10 as follows:
- 5 points are for the assignment description, comments in the code, and documentation in general.
- 10 points are for writing Java code in a good style that is easy to understand, that your programs meet the requirements and produce nice output. Some of the points in this partial will be for effort and uniqueness.