I need selecting which design pattern to use in my case.
I am creating a list of objects "items" to be presented in a list for the user to choose from, all objects have a title and a check box. Some objects have additional textbox for user input, some objects have additional image for illustration, and some objects have additional textbox and image as well.
I read and saw online videos but not sure if my selection "Factory Design Pattern" is the best match.
I have a design scenario here which is quite interesting and complex. I have a Java class structure as follows,
class A { class B; innerClass B { List<class C> listofC; innerClass C { String attribute1; String attribute2; // Their getter setters } } }
So I have this as an API. Now my challenge is that I need to add one more property to inner class C. i.e attribute3 in innerClass C. I need to do this without disturbing the code in class A by extending these classes or writing a new wrapper, so I can use class C with new properties .
I hope this should be achievable through any design pattern either at runtime or design time.
One of the four JDialog class would look something like this without the comments.
package client; import javax.swing.JDialog; @SuppressWarnings("serial") public class AddCustomerDialog extends JDialog implements Dialog{ public AddCustomerDialog () { //Some stuff goes here to set the settings for JDialog instance
design a class to conduct a survey of three hospitals. you want to know how many sectors (eg operation, children, gastronomic) each hospitals have, and how many doctors there are in each sector.
we have been given a scenario to design a system in which we have to make the class diasgrams. however we have to use appropriate patterns that match the scenario.
Basically I have to enter 5 numbers that I put through a loop and they print the star * depending on the number.An example would be this 5:*****. However, my codes prints out 5:*; 5 times. How to correct my code
Java Code:
import java.util.Scanner;
public class IntegerOutput { public static void main( String args[] ) { Scanner input = new Scanner( System.in );
I have done this a few times but I want to make sure I am doing it correctly. In other words creating a clean understandable program. Instead of posting code I will just talk about this is my plan:
Create a model (getter and setters) Create a view (via swing) Create a controller (pass the model and view in the parameter)
Database DatabaseConnection: Use the singleton pattern
Database: Create an interface called Database with all the queries I will need (insert, delete etc) Create a class called DataBaseDAO and implement the interface database and get an instance of the DatabaseConnection.
Tying it all together:
In the controller should I use the "new" operator and create a new database class or extend the database class? I am thinking I should not do it in the controllers constructor but make a field if I use the "new" operator like:
private Database db = new Database(); Create a class called App Create a new Model Create a new View Pass the view and model into the controllers parameter.
Am I on the right track? Is this messy? Is there a better way of doing it?
I am able to get Cpu speed using my GetProcessorSpeed method and It returns this output 1796. How can apply this pattern "#.##". I am trying something like this.
Format formatter=new DecimalFormat("#.##"); formatter.format(MainClass.GetProcessorSpeed()); label2.setText(formatter.toString());
This program allows the user to select one of each different type of skateboard/accessories items. Then it allows the user to select as many misc items as he or she chooses. The program works fine for the single choices, but I cannot solve the latter part. I have a get method in the misc class that is trying to pull out any selection or selections that were made by the user, but it simply does nothing...
Here's my program, I have four panel classes for each skateboard type, and then I have one class that takes care of adding each panel to the content pane, and calculating the total cost of the item.
Decks Panel Class:
import java.awt.event.*; import javax.swing.*; // The DecksPanel class allows the user to selects a specific type of skateboard public class DecksPanel extends JPanel
However, whenever I run the method, the element that should go last, Zachary, in this case, ends up getting moved to the front for some reason. I'm not sure why.
I tried changing what the first element was initialized to, to the variable i as that would logically work as well, but it ends up missing the first element in the list.
Java Code:
public static void selectionStringAscendingSort (String[] words){ int i, j, first; String temp; for ( i = 1; i < words.length; i++ ) { first = 0; //initialize to subscript of first element for(j = i; j < words.length; j ++){ //locate smallest element between positions 1 and i. if( words[ j ].compareTo(words[ first ]) <0 ) first = j; } temp = words[ first ]; //swap smallest found with element in position i. words[ first ] = words[ i ]; words[ i ] = temp; System.out.println(Arrays.toString(words)); } System.out.println(Arrays.toString(words)); } mh_sh_highlight_all('java');
I am in an intro programming class and we got assigned a problem for creating a super class with about a dozen sub classes for generating a random word(via WordGetter class) and then comparing that word to a variety of different patterns(like: does the word contain "re"). We were given the super class which looks like this...
public class Pattern { public boolean matches(String text) { return true; } public String toString() { return "(TRUE)";
[code]...
and from this class, we have to write subclasses that override those three methods. I am struggling to understand inheritance and I am not really sure where to even start. Here is the instructions for the first sub class we need to write...
"CONTAINS" SUBCLASS Constructor: The constructor accepts a String named ‘letters’.
Matches: This pattern matches any text that contains at least one occurrence of each ‘letter’. toString: produces the text “(CONTAINS <LETTERS>)” where <LETTERS> is the ‘letters’ string. getLetters(): this method must return letters. equals(Object): careful on this one. Two Contains are equal if they have the same letters (order is not relevant). (Example):
Pattern p = new Contains(“re”); boolean f1 = p.matches(“renew”); // f1 is true boolean f2 = p.matches(“zoo”); // f2 is false String s = p.toString(); // s is “(CONTAINS re)” boolean f3 = p.equals(new Contains(“er”)); // f3 is true.. really..
I'm trying to run a simple code which is to just print out "Hello World", but whenever I run it, a message appears that reads: "Select a way to run Project_1(Which is the Java Project)"
The selections for it are: Java Applet and Java Application.Whenever I click Java Applet it reads: Selection does not contain an applet.When I click Java Application: Selection does not contain a main type.Here is the code which I believe is correct:
package packag_1; public class Num_1 { public static void main(String args){ System.out.println("Hello World"); } }
I'm having a hard time implementing a simple composition example in Java:
Java Code:
public class CompositionPattern { public static void main(String[] args) { Udp udp = new Udp(); Imap imap = new Imap(); udp.startService(); imap.startService();
[Code] ....
The above won't compile. It says "The method supportsMe() is undefined for the type Object". I understand that I stored parent as an Object. But in reality it is not simply Object, but a Udp object or Imap object. The point is to make Responder generic. I don't want to have to cast the Object to Udp or Imap. Any solutions so I can keep this generic?
Model View Controller design pattern I completely understand then I was told about the observer controller pattern. After reading and reading I and watching video clips on youtube explaining it I have a question:
Isn't the actionListener the observer so to speak. It is firing whatever action it is told to do and dynamically updates the program to.
Example, I have a JButtons and a JTextArea. I press the button and it gives the current stock price of some stock, I press it again it refreshes. Sounds like an observer to me... Am i on the right track here?
