Managing Class Paths On Different Operating Systems
Jun 5, 2014
I use git as my SCM and I use both Ubuntu and Mac OSX. The home directory of the two operating systems are different and there lies the problem. When I commit the .classpath to version control, it looks something like this:
Now when I update my project on Ubuntu. I have to change the build path again because it is referencing paths on OSX. And this goes back and forth. Rather than remove this file from git with .gitignore, I'd prefer to use a global environment variable like as follows:
I am attempting to use JLists to complete a program that models how operating systems manage processes. A quick synopsis of what it is supposed to do. Each process is to have a priority level (I chose to do 1 -3 with 3 being the most important) and there are supposed to be three lists. One for ready processes, blocked processes, and a running process.
My issues:
1) when I block a process it does indeed switch lists but when it is copied into the blocked list it pulls the element number instead of what the actual process number is. For ex: Say the ready list has 5 processes / I delete 2 / Leaving process 1, 2, 5. When I block 5, it gets registered in the blocked list as process 2.
2) I can't figure out how to give a label to each of my scroll panels (JLists) to signify which box is ready / blocked / and running
3) My switch button - I have commented in what I need to do but don't know how I am going to do it.
Below are my files:
Main
import java.util.Comparator; import java.util.PriorityQueue; import java.util.Queue; import javax.swing.JFrame; import javax.swing.JTextArea; public class PQueue { public static void main(String[] args) throws InterruptedException {
I'm doing a little game in Java and I would like to insert a background music managed by a JButton. When the button is pressed, the music starts and then, to stop it, the button is pressed again. If you don't press the button to stop the music remains in the loop until the player plays.
I and a friend are working with a project to create a file system, who manages a secondary memory simulated as a byte array in Java. We want the file system to be a hierarchical tree structure like in UNIX.
We have come quite far, but the paths are not handled correct. I seem to have mistaken the relative folder ./ for the root folder, but it should mean "working directory folder", ie, where I stand now. That is, if I stand in /dir1 as my "working directory" and make mkdir ./dir2 then should dir2 end up as subfolder in dir1. But with me it appears in the root.
I'm new to java and haven't develop any application before that... I need to develop an application through which i can send data from 1 computer to another computer. These communication in between the computers are those are under one router connection. Means they can connect even without internet access
Main concept is as follow
1. Java application on computer A [server side application] 2. Java application on Computer B [Client side application] 3. Java application on computer C [Client side application]
Now computer B and C communicate with computer A. but they don't know about presence of each other
This piece of java software I am responsible for is running throughout numerous locations in my country, there is only 1 location which has trouble with the dates being displayed incorrectly, birthdates of clients are displayed as a day earlier. It seems pretty safe to say it is a problem on their end... But still, they're asking me for an explanation as to why java would treat a date differently in this rare case.
The date (a birthdate) comes from an oracle database, it is a date without a time (trunced date). It enters the application as a member of the client-class, it is NOT being set or changed after that. It goes through several layers in the application, then ends up in a GUI class which unwraps it from the "client"-object and puts a SimpleDateFormat (new SimpleDateFormat("dd-MM-yyyy")) on it. My first and only hunch was the timezone settings, but that seems to be OK!
I've been trying to send a file(text & image files) from one system to another. somewhat I did, but file is not send originally in destination system. It shows AccessDeniedException on the destination system. What should do to avoid this exception.
I know what the tree data structure is, how it works, etc., but I need to design a method that will sequentially print out all the paths in the tree (i.e. for each node).
The pseudocode I was thinking of doing was something along the lines of:
paths if(root.getData() = null) return paths; path = ?; // absolutely no clue what to do here paths += root.getData() + " " + path + " "; if(root.hasLeftChild()) { newPath += "0"; paths += begin recursion; } if(root.hasRightChild()) { newPath += "1"; paths += begin recursion; } return paths;
Problems:
(1) I don't know how to determine "path" before the left and right children check (the root node's path is "", the first left node's path is "0", the first right node's path is "1", pattern continues with left being "0" and right being "1"). (2) I don't know where to put newlines precisely. (3) I'm not sure how to get the print layout precisely as it is supposed to be. At most I've been able to just get the last number in the sequence (i.e. if it was supposed to be "1000", I could get "0".
I am working with the pseudocode formulation, especially in regards to the logic and formatting. I think once I have an understanding of what is going on, I can solve it. And yes, I've gone through a couple pseudocode rewrites (a few hours worth) and haven't gotten anywhere which is slightly unnerving.
I can't get Relative paths to work. I have created the class.dat file and I can't get java to recognize it. I am using Eclipse as an IDE. Was wondering if I could get Eclipse to recognize it. I tried with a .txt file as well and couldn't get that to work.
import java.io.*; public class ReadBytes { public static void main(String[] args) { try { FileInputStream file = new FileInputStream("class.dat");
So I downloaded jgrasp and eclipse on a new computer and am trying to figure out how their filing/path system works.In eclipse I created a new project under which I've imported all my files for my comp sci class, so they're all under this one project which is my only project. I attached a pic of what my eclipse workspace looks like. In this project folder is a file I'm trying to run.
I keep getting an error saying "editor" does not contain a main type.When I change my class name to the project folder I end up getting an option to run the program as an applet or an application, but either one I choose I get the same error message. In the bottom it gives me a warning saying
DescriptionResourcePathLocationType Build path specifies execution environment CDC-1.1/Foundation-1.1. There are no JREs installed in the workspace that are strictly compatible with this environment. CS1050AssignmentsBuild pathJRE System Library Problem
I tried running the program in jgrasp and got this error
----jGRASP wedge2 error: command "javac" not found. ---- This command must be in the current working directory or ---- on the current system PATH or jGRASP PATH to use this function. ---- System + jGRASP PATH is "C:UsersQudrat.MommandiDocuments;C:Windowssystem32;C:Program Files (x86)InteliCLS Client;C:Progra
[code]...
I have the JDK installed in program files, I have the correct versions of eclipse and Jgrasp, and have uninstalled / reinstalled the JDK/Jgrasp/Eclipse so I don't know what the problem is?
I am trying to make a GUI that allows the user to input the NumberLink puzzle (through mouse action events), and then, displays the puzzle in a grid with features to draw a path, and undo it. This is almost exactly the same functionality as in Numberlink on Nikoli
1. In my project, I have a Stage in which a setup scene prompts user for rows and columns (to take size of puzzle),
2. Then, it generates an empty grid (I'm thinking of using a GridPane here), and the user clicks the squares to enter the numbers into the square. this phase isnt a problem if I use text fields and mouse listeners and store info in a grid... the next phase is what I'm stuck at... unless I know exactly how to do that, I cant make progress...
3. In the third stage, I have to display the numbers to the user just like on the Nikoli site (the highlighting number pairs on mouse hover is a necessary feature too, which I think I can handle with CSS).. and the user should draw paths between the numbers, just as on that site ( I thought VLineTo and HLineTo classes would be suitable.. but I'm not sure, and cant find any alternatives) .....
So with this in mind, I made FXML based dummy gui layouts to test if my ideas work... And I cant get the GridPane to have lines drawing atop it (meaning, I cant place Line objects like HLine on top of the grid panes).... is there any other way to do what I need to do ? I also thought of making canvases in a grid (each square is its own canvas)
How I can implement a user inputted path drawing ??
Is it possible to find the number of paths between two nodes in a directed graph using an adjacency matrix? I know how to find all said paths of a given length by using matrix exponentiation, but I don't know how to find all the paths. The professor didn't note it in the assignment but I assume she meant all simple paths because this is a cyclic graph, so there's a potentially infinite number of paths.
I'm thinking I should use matrix exponentiation to find the number of paths of lengths 1 to n-1, where n is the number of nodes in the graph. Then add the number of paths for each length together. Would this work?
I've been pondering about this algorithm for about a week but I'm still not able to write a "fast" working method/algorithm to solve the Number-of-paths-exercise we were given in my class />
So here's the task: Write an efficient java program "Paths" which solves the following task:
- Read input n ∈ N and give output a(n) which is the number of paths from (0,0) to (n,0) it is not allowed to go over the diagonal (m,m) and also not below the x-axis (m,0)
Here are the allowed steps: u = (1,1), U = (1,4), d = (1,−1), D = (1,−4) and H = (1,0) steps are performed in a two-dimensional-coordinate-system!
We have Starting point that is (3,0) and an ending point is (1,3). We can only move up and right to get to the ending point by using recursion. We have to list all possible paths from (3,0) to (1,3)
We have Starting point that is (3,0) and an ending point is (1,3). We can only move up and right to get to the ending point by using recursion. We have to list all possible paths from (3,0) to (1,3)
I was able to get from (3,0) to (1,3) but how to list the other paths. This is my code so far
public class Program7 { public static void main(String[] args){ int size = 5; int x1 = 3; int y1 = 0; int x2 = 1; int y2 = 3; System.out.println(x1+" "+y1); System.out.println(x2+" "+y2);
But for the method get() of Paths, I get this error in eclipse.The method get(String, String[]) in the type Paths is not applicable for the argument..Yet on the Oracle documentation site, it uses a similar example:
Is there some way to create compound shapes/paths in JavaFX?
For the record I'm not implying the use of the methods intersect, subtract, or union. These produce other shapes. A compound shape/path is one that has a knockout of some sort. For instance, a circle within a circle, such as in a 2d donut shape. Alternatives do not include a circle with a thick stroke nor an overlayed circle with the background color. Specifically, JavaFX supports the FillRule, in the case of the Path object. However, there doesn't appear to be an "add" method as there was in the Area shape in Swing.
I am developing an web application with servlets and jsp. I have an issue to store images. I am storing images in folder and their relative path's in mysql database.
When I retrieve path from database then using <IMG> tag i have displayed image like:
How do you declare methods for a class within the class whilst objects of the class are declared else where?
Say for instance, I have a main class Wall, and another class called Clock, and because they are both GUI based, I want to put a Clock on the Wall, so I have declared an instance object of Clock in the Wall class (Wall extends JFrame, and Clock extends JPanel).
I now want to have methods such as setClock, resetClock in the Clock class, but im having trouble in being able to refer to the Clock object thats been declared in the Wall class.
Is this possible? Or am I trying to do something thats not possible? Or maybe I've missed something really obvious?
Regarding the lifecycle of servlet , in headfirst servlet i can find :
You normally will NOT override the service() method, so the one from HttpServlet will run. The service() method figures out which HTTP method (GET, POST, etc.) is in the request, and invokes the matching doGet() or doPost() method. The doGet() and doPost() inside HttpServlet don’t do anything, so you have to override one or both. This thread dies (or is put back in a Container-managed pool) when service() completes.
How can I call the doGet method of the subclass from the superclass. i am not getting this .
I have a quick polymorphism question. I have a parent class and a sub class that extends the parent class. I then declare an array of parent class but instantiate an index to the sub class using polymorphism. Do I have to have all the same methods in the child class that I do in the parent class? Here is an example of what I mean.
public class ParentClass { public ParentClass(....){ } public String doSomething(){ } } public class ChildClass extends ParentClass { public ChildClass(....)
[Code] ....
Is polymorphism similar to interfaces where the child class needs all the same methods?
I want to know is there any way we can call parent class method using child class object without using super keyword in class B in the following program like we can do in c++ by using scoop resolution operator
class A{ public void hello(){ System.out.println("hello"); } } class B extends A{ public void hello(){ //super.hello(); System.out.println("hello1");
i want to write a class in such a way that i should get the current execution time of another class which is running. I searched in net but it shows only how to calculate the time duration of the current class which is running. But as per my way, i need the execution time of one class from another class. How to do this ?
