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Using CHelper plugin in IntelliJ for a coding contest

I quite recently discovered a coding site, with coding contests : CodinGame, and in order to solve the problems, we have to hand them over only one file with a main (in the following example, the class Player), and if other classes are needed, we include them in this file.
For this purpose (and seen to be working for another coding site), I have downloaded intelliJ and the plugin CHelper in order to put all the source files into one java file (it is supposed to be the purpose of the CHelper plugin). The problem is: I don't understand how to use/setup this plugin for my coding site. I know it should work because another user of this site has already used the plugin for this purpose.
What I want
For a more detailed example of what I want, here is the class with a main:
// Class Player in file Player.java
public class Player {
public static void main(String[] args) {
System.out.println(new Cell(1,2).toString());
}
}
And this class Cell is in another java file :
// Class Cell in file Cell.java
public class Cell {
int x,y;
public Cell(int x, int y) {
this.x = x;
this.y = y;
}
public String toString() {
return "["+x+","+y+"]";
}
}
And I would like the plugin to merge the two (or more) java files in order to have this :
// Generated : 2 files merged into one file: Player.java
public class Player {
public static void main(String[] args) {
System.out.println(new Cell(1,2).toString());
}
// Class Cell merged in this file
public class Cell {
int x,y;
public Cell(int x, int y) {
this.x = x;
this.y = y;
}
public String toString() {
return "["+x+","+y+"]";
}
}
}
What I achieved
I installed IntelliJ correctly, and downloaded the CHelper plugin.
I installed the toolbar menu buttons linked to TopCoder (the site that this plugin is expressly made for), but the Launch TopCoder button throws a RuntimeException : cannot run program .../javaws no such file.
With some tasks downloaded from TopCoder, I succeeded in merging 2 files into one : TaskA.java into Main.java (with templates downloaded)
What would be ideal
If an Eclipse plugin could work like what I want, I would be very happy to know of it. In fact, that was what I was looking for at the beginning of my search, and I only found some plugin for the IntelliJ IDE.

So I finally found a way to do what I wanted: the guy who had done it shared me a link to the help I needed.
I am going to sum it up specifically for CodinGame here.
I- Toolbar buttons
The important buttons to add to the menu toolbar are
create new task
modify task
delete task
Edit project settings
Now, we have some buttons in the red rectangle :
II- Edit settings
Then we have to edit project settings :
set the default directory to your default package
output directory is for the generated source file
III- Create task
Next thing, we have to create a new task (green "+" button) and set it up using the advanced option. We add the tests input and known output with the button Edit tests. We say we want the generated file to be called Solution.java, and the class where we are going to write is going to be called CGXFormatter.java
We now have two files which have appeared in our package .../puzzle :
CGXFormatter.java with a method solve, which is where we are going to read the input and give our answer in the output
CGXFormatter.task, which contains the info on the test cases, etc. in order for the plugin to generate the source file
IV- Write your solution
For example, we are just going to print "This is the result" in our CGXFormatter class (but we could have created another class file and called it, it would have worked by copying the definition of the class in the generated solution class). Like this :
package com......puzzle;
import java.util.Scanner;
import java.io.PrintWriter;
public class CGXFormatter {
public void solve(int testNumber, Scanner in, PrintWriter out) {
out.println("This is the result");
}
}
V- Generate the solution
Last step: click on run. Then we have the directory generated which is created, and in it, we have the Solution.java file newly generated. We can read this :
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;
/**
* Built using CHelper plug-in
* Actual solution is at the top
*
* #author XXX
*/
public class Solution {
public static void main(String[] args) {
InputStream inputStream = System.in;
OutputStream outputStream = System.out;
Scanner in = new Scanner(inputStream);
PrintWriter out = new PrintWriter(outputStream);
CGXFormatter solver = new CGXFormatter();
try {
int testNumber = 1;
while (true)
solver.solve(testNumber++, in, out);
} catch (UnknownError e) {
out.close();
}
}
static class CGXFormatter {
public void solve(int testNumber, Scanner in, PrintWriter out) {
out.println("This is the result");
}
}
}
VI- Last step
Okay, there still remains a little problem: in CodinGame, the solution class should not have public in front of it, so just put class Solution instead of public class Solution and you're done.
If you want, you can also put it in a script to do it automatically with a multirun (plugin to install in IDEA, also).
That's it, you're done.
VII- Edit Octobre 2019
If the plugin complains about not finding a net.egork.... class, you can add these steps that I found here
Update Intellij IDEA to the latest version. Secondly, you go to File
-> Settings... -> Plugins and search for the chelper plugin. It is required to run the task run configurations, and it supplies you with
the buttons on the toolbar, too. After you have done that, you should
be getting the error about impossibility to find and load class from
net.egork... Now you go to the jetbrains plugin site, search for
chelper plugin there, and download the latest zip archive. After
unzipping it, go to File -> Project Structure... -> Libraries -> + ->
Java, select recursively the folder you just unzipped until you get to
a bunch of jars that contain that missing class in the error. After
you have added those jars to your classpath, along with JDK, it should
be enough
As a side note, I remarked that the out.println didn't work as I intended (I don't know why), so I replaced it by System.out.println instead of using the proposed out object in the solve method.

Problems using Matlab Builder JA

First of all I would like to thank in advance everyone for reading such a long post. I really appreciate your help.
The thing is that I've been doing some research on how to "connect" Matlab and Java for a project I am working on for university. I figured that the most suitable option was using Matlab Builder JA, but I'm having a lot of troubles with it.
I follow step by step the instructions described on a tutorial (the link of the video in below) but get compilation errors over and over, and I really don't know how to fix them. The tutorial is about creating a Java package (demo.jar) with MATLAB ("com.demo"), which contains a class (MLTestClass) with a function makeSqr(n) which returns an n × n square matrix. Then I go to Eclipse, I add to the project both libraries javabuilder.jar and demo.jar and then create the following class:
public class Driver {
public static void main (String[] args) {
MLTestClass x = null;
Object result [] = null;
try {
x = new MLTestClass ();
result = x.makeSqr (1, 5);
System.out.println (result [0]);
} catch (MWException e) {
e.printStackTrace();
}
}
}
Of course I import com.demo.* and com.mathworks.toolbox.javabuilder.*.
Here are the errors the console gives me:
Exception in thread "main" java.lang.ExceptionInInitializerError
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration.getProxyLibraryDir(MCRConfiguration.java:163)
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration$MCRRoot.get(MCRConfiguration.java:77)
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration$MCRRoot.<clinit>(MCRConfiguration.java:87)
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration.getMCRRoot(MCRConfiguration.java:92)
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration$ModuleDir.<clinit>(MCRConfiguration.java:66)
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration.getModuleDir(MCRConfiguration.java:71)
at com.mathworks.toolbox.javabuilder.internal.MWMCR.<clinit>(MWMCR.java:1573)
at com.demo.DemoMCRFactory.(DemoMCRFactory.java:122)
at com.demo.MLTestClass.(MLTestClass.java:63)
at Driver.main(Driver.java:12)
Caused by: java.lang.NullPointerException
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration$ProxyLibraryDir.get(MCRConfiguration.java:143)
at com.mathworks.toolbox.javabuilder.internal.MCRConfiguration$ProxyLibraryDir.<clinit>(MCRConfiguration.java:158)
... 10 more
Just in case, link tutorial (it's the video): http://www.mathworks.nl/products/javabuilder/description2.html
Anyone has any ideas what the problem could be? It says something about NullPointerException, but I don't know how to solve it as the constructor is provided by the class created with MATLAB. I didn't have any issues installing MCR, and by the way I have MacOS, which I hope is not the source of the problem :).
Again, sorry for the long post and thank you for your time.
Béntor.

Yes, please install MCR. The installation also mentions about setting environmental variables like LD_LIBRARY_PATH etc. If you are using eclipse, i would recommend you update the environmental variables
right click->
properties ->
run/debug settings->
environmental variables
I also had to make sure that variable MCR_CACHE_ROOT pointed to different directory since my home directory was not big enough.

You have install MCR (avaliable in http://www.mathworks.com/products/compiler/mcr/index.html)

None of the above solutions helped me (I already had MCR installed and Macs use DYLD_LIBRARY_PATH instead of LD_LIBRARY_PATH), and noone else online seemed to know. Finally in desperation, I tried editing the DYLD_LIBRARY_PATH and finally got it to work by removing the last part of it: /Applications/MATLAB/MATLAB_Compiler_Runtime/v82/sys/java/jre/maci64/jre/lib
Now the demo application from the tutorial works.
Next comes trying to make my code work.

OS X Paths for Run-Time Deployment
Use these setenv commands to set your MATLAB Runtime paths.
setenv DYLD_LIBRARY_PATH \
mcr_root/version/runtime/maci64 \
mcr_root/version/bin/maci64 \
mcr_root/version/sys/os/maci64
Source: http://www.mathworks.com/help/compiler_sdk/java/mcr-path-settings-for-run-time-deployment.html

NetBeans is not debugging correctly after I copy sources

Dunno why this happens... Ok here is the situation: I have a nb project on my laptop. I have the same project on my desktop. I copy the sources (not the entire project) on the desktop, overwriting the desktop sources. Everything cleans and builds ok. Then I start the debugger. On the main class I can debug step by step. If it goes into an internal method here is what happens:
Listening on 37574
User program running
LineBreakpoint test.java : 45 successfully submitted.
Breakpoint hit at line 45 in class test by thread main.
Thread main stopped at test.java:45.
User program running
Not able to submit breakpoint LineBreakpoint baseControllerManager.java : 41, reason: No executable location available at line 41 in class baseClasses.JNW.baseControllerManager.
Invalid LineBreakpoint baseControllerManager.java : 41
Debugger stopped on uncompilable source code.
User program finished
As you can see until I'm in static method main it works (line 45) as I jump inside a non static method (that is an override) it comes out with that... I tried to:
clean and build = no effect
manually delete build and dist = no effect
What do you suggest?
For the sake of completeness I'm attaching the sources of the main class:
import baseClasses.JNW.baseAction;
import baseClasses.JNW.baseContResult;
import baseClasses.JNW.baseController;
import baseClasses.JNW.baseControllerManager;
public class test {
public static class starter extends baseController {
public static final String ACTION_START = "ACTION_START";
#Override
public baseContResult doAction(baseAction action) {
if (ACTION_START.equals(action.action)) {
manager.log("action start...");
return new baseContResult(RESULT_OK, baseContResult.resultType.RESULT_OK);
}
return super.doAction(action);
}
#Override
public void init() {
super.init();
}
}
public void startMe() {
baseControllerManager manager;
try {
manager = new baseControllerManager();
} catch (Exception e) {
e.printStackTrace();
return;
}
starter st = new starter();
manager.setMainController(st);
manager.doAction(new baseAction(starter.ACTION_START));
}
public static void main(String args[]) {
test te = new test();
te.startMe();
}
}

Look in the file nbproject/project.properties for the property javac.debug and make sure that it's "true". If it is, grep for that property elsewhere in the nbproject directory and any local ant settings.
On a semi-related note: when I'm creating a project in NetBeans, even if the sources already exist elsewhere, I always create a new "Java Application", and let it populate the project directory as it wants. Then I can move in my sources and update the project, and NetBeans stays happy.
Edit after you tried setting javac.debug:
Looking at your question again, I see that you were able to set a breakpoint on test.java, but not able to set one on baseControllerManager.java. That indicates to me that you're getting the latter class from a JAR somewhere, not from your project directory.
So the first step is to make sure that you haven't defined a CLASSPATH environment variable. This is never a good thing to do, regardless of whether you're using an IDE or a manual build.
Next step is to look at the libraries that you've specified for the NetBeans project. You can use grep on a JARfile; the file directory is in plaintext. It should be sufficient to look for the unqualified classname.
And the final thing is to verify that you are indeed compiling the class, by looking for it in the build directory.

Generally, an uncompilable error means a symbol could not be resolved.
If you have dependencies on other projects, libraries, or jars, make sure they have built successfully / are present.
Checking "Build Projects on Classpath" (in project properties > Build > Compiling) will often fix this. If you don't have this checked, you are responsible for ensuring dependencies are already built.

The property was not present in project.properties. So I added it (at a point where there where many javac.* properties...). Then I grepped like this:
dario#dario-desktop:~/Scrivania/JNW$ grep -r javac.debug *
nbproject/project.properties:javac.debug=true
nbproject/build-impl.xml: <property name="javac.debug" value="true"/>
nbproject/build-impl.xml: <attribute default="${javac.debug}" name="debug"/>
nbproject/build-impl.xml: <javac debug="#{debug}" deprecation="${javac.deprecation}" destdir="#{destdir}" encoding="${source.encoding}" excludes="#{excludes}" fork="${javac.fork}" includeantruntime="false" includes="#{includes}" source="${javac.source}" sourcepath="#{sourcepath}" srcdir="#{srcdir}" target="${javac.target}" tempdir="${java.io.tmpdir}">
nbproject/private/private.properties:javac.debug=true
nbproject/project.properties~:javac.debug=true
In fact it sees my addition on the last line.
I cleaned and rebuilt the project. The debugger is not working again........... I think I'll kick my boss ass until he agrees to use eclipse or he fires me. I'll be unemployed but happy. Apart from joking, #kdgrgory, do you have any more ideas???

I had the same problem and found that if I run clean from project tab it solves the problem.

Why does my icon handling code throw a NullPointerException?

I have added an image for my button,but when I run that frame this exception will be thrown .why?please help me.
init:
deps-jar:
compile-single:
run-single:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:138)
at ClientGUI.IdAndPasswordFrame.initComponents(IdAndPasswordFrame.java:91)
at ClientGUI.IdAndPasswordFrame.<init>(IdAndPasswordFrame.java:22)
at ClientGUI.IdAndPasswordFrame$4.run(IdAndPasswordFrame.java:200)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)
BUILD SUCCESSFUL (total time: 1 second)
line 138:
public ImageIcon (URL location) {
this(location, location.toExternalForm());
}
line91:
jButton1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/Images/yahoo_1.gif"))); // NOI18N
I use this poor checking (Peter Lang recommended)which is:System.out.println(getClass().getResource("/Images/yahoo_1.gif")); and it returns null,why? please help me.

This means, that getClass().getResource("/Images/yahoo_1.gif") returns null.
JavaDoc states that this happens if
the resource could not be found or the invoker doesn't have adequate privileges to get the resource.
Check if getResource really returns null:
System.out.println(getClass().getResource("/Images/yahoo_1.gif"));
Make sure that your path is correct and that it is in your classpath.
EDIT:
I just tried it with NetBeans. I created the following structure
Source Packages
Images
yahoo_1.gif
and your code worked fine. Is this your structure?
Try to right-click on your application and select Clean and Build.

In order to fix this, the images need to be copied in the bin directory - not in src directory.
Otherwise you will get null all the time on getClass().getResource("image.png").
The path is not null and you can set it as the above - only if you copy the images that you need inside the binary directory, where .class files for your project are located.
This fixed the problem. Let me know if I helped in this.
Ioana

I had the same problem. What worked for me was:
Look into the jar file or in the bin folder(the one with .class files) and see the path of image.
List item

It looks like getClass().getResource("/Images/yahoo_1.gif") returns null i.e. the .gif cannot be found on your classpath. (Images versus images maybe?)

The URL being passed in is null from this line:
getClass().getResource("/Images/yahoo_1.gif")
From the JDK documentation:
[getResource(..) returns] A URL object for reading the resource,
or null if the resource could not be
found or the invoker doesn't have
adequate privileges to get the
resource
Maybe you meant ("Images/yahoo_1.gif") - i.e. relative path not absolute?

private class HandlerClass implements ActionListener{
public void actionperformed(ActionEvent event){
JOptionPane.showMessageDialog(null, String.format("%s", event.getActionCommand()));
}
}

After reviewing some things when trying to add an image I was presented with the same problem that usually occurs in project with maven.
I found a solution that uses the full path to be able to access the image. Also, create a function that returns an icon with the image and automatically scaled according to the dimensions that are sent to it.
Path -> directory where the image is located, width -> width of the icon, heigth-> height of the icon I hope it serves you, this is my first contribution in the community
public Icon getIcon(String ruta, int width, int heigth) {
Image image = (new ImageIcon(ruta)).getImage().getScaledInstance(width, heigth, 0);
Icon mIcono = new javax.swing.ImageIcon(image);
return mIcono;
}

How do relative file paths work in Eclipse?

So my 2009 new years resolution is to learn Java. I recently acquired "Java for Dummies" and have been following along with the demo code in the book by re-writing it using Eclipse. Anyway, every example in the book that uses a relative path does not seem to read the .txt file it's supposed to read from.
Here is the sample code:
import java.util.Scanner;
import java.io.File;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JLabel;
import java.awt.GridLayout;
class TeamFrame extends JFrame {
public TeamFrame() throws IOException {
PlayerPlus player;
Scanner myScanner = new Scanner(new File("Hankees.txt"));
for (int num = 1; num <= 9; num++) {
player = new PlayerPlus(myScanner.nextLine(), myScanner.nextDouble());
myScanner.nextLine();
addPlayerInfo(player);
}
add(new JLabel());
add(new JLabel(" ------"));
add(new JLabel("Team Batting Aberage:"));
add(new JLabel(PlayerPlus.findTeamAverageString()));
setTitle("The Hankees");
setLayout(new GridLayout(11,2));
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setVisible(true);
}
void addPlayerInfo(PlayerPlus player) {
add(new JLabel(player.getName()));
add(new JLabel(player.getAverageString()));
}
}
And you can see in the below screen shot I have included this file.
image no longer available
Also, I have verified that when I build the application that a copy of Hankees.txt is placed in the bin folder with the compiled .class files.
Lastly, if I change line 12 to the following and place Hankees.txt in the root of my C:\ drive the program compiles and runs fine.
Scanner myScanner = new Scanner(new File("C:\\Hankees.txt"));
So basically, my question is what am I doing wrong? Or is Eclipse responsible for this in some way?
Thanks for any and all help!

You need "src/Hankees.txt"
Your file is in the source folder which is not counted as the working directory.\
Or you can move the file up to the root directory of your project and just use "Hankees.txt"

A project's build path defines which resources from your source folders are copied to your output folders. Usually this is set to Include all files.
New run configurations default to using the project directory for the working directory, though this can also be changed.
This code shows the difference between the working directory, and the location of where the class was loaded from:
public class TellMeMyWorkingDirectory {
public static void main(String[] args) {
System.out.println(new java.io.File("").getAbsolutePath());
System.out.println(TellMeMyWorkingDirectory.class.getClassLoader().getResource("").getPath());
}
}
The output is likely to be something like:
C:\your\project\directory
/C:/your/project/directory/bin/

This is really similar to another question.
How should I load files into my Java application?
How should I load my files into my Java Application?
You do not want to load your files in by:
C:\your\project\file.txt
this is bad!
You should use getResourceAsStream.
InputStream inputStream = YourClass.class.getResourceAsStream(“file.txt”);
And also you should use File.separator; which is the system-dependent name-separator character, represented as a string for convenience.

Yeah, eclipse sees the top directory as the working/root directory, for the purposes of paths.
...just thought I'd add some extra info. I'm new here! I'd like to help.

You can always get your runtime path by using:
String path = new File(".").getCanonicalPath();
This provides valuable information about where to put files and resources.

Paraphrasing from http://java.sun.com/javase/6/docs/api/java/io/File.html:
The classes under java.io resolve relative pathnames against the current user directory, which is typically the directory in which the virtual machine was started.
Eclipse sets the working directory to the top-level project folder.