With this program I am attempting to have the user select a text file that is a representation of a 4x4 sudoku problem. My agent will then take this file and attempt to solve the sudoku puzzle.
The problem I'm running into is that I can't seem to figure out how to get the proper file selected, and then passed into the method call for processing.
This is the file selector class I've created. So far it successfully brings up a button, and when clicked brings up the computer's file structure so the user can select a file.
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
/**
* Created by neil on 7/12/17.
*/
public class file_selector {
public JPanel panel1;
public File file;
JButton button1;
public file_selector() {
final JFileChooser fc = new JFileChooser();
button1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
int returnVal = fc.showOpenDialog(null);
if (returnVal == JFileChooser.APPROVE_OPTION) {
file = fc.getSelectedFile();
System.out.println("You chose to open " + file.getName());
}
}
});
}
public File getFile() {
return file;
}
}
This is my main method in which I attempt to use the file that the user selected. When I put the function calls in a while loop (like it is currently) it never proceeds because the file is never set. If I don't put the function calls in a while loop, I get a nullPointerException error when I try to process the file because the file has a null value.
public class sudoku {
//create 2d array that represents the 16x16 world
public cell[][] world_array = new cell[15][15];
static File myFile;
ArrayList<String> world_constraints;
public static void main(String[] args) throws IOException {
JFrame frame = new JFrame("file_selector");
file_selector fs = new file_selector();
frame.setContentPane(fs.panel1);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
myFile = fs.getFile();
while(myFile != null) {
sudoku my_puzzle = new sudoku();
my_puzzle.solve_puzzle();
}
}
I've done a ton of searching and can't seem to find what's wrong with my file_selector class such that it isn't setting the user selected value for the file.
You call getFile immediately after showing the frame and before the user has opportunity to click anything. Since the condition for while is false, the loop ends immediately and the method doesn't do anything afterwards, in particular it never calls getFile again.
Two options:
Make the button solve the puzzle, not just set file (easier, just change actionPerformed method).
Make file_selector emit an event when a file is selected and add a listener to it (this can be a challenge for you).
Related
I'm making a basic IntelliJ plugin that lets a user define Run Configuration (following the tutorial at [1]), and use said Run Configurations to execute the file open in the editor on a remote server.
My Run Configuration is simple (3 text fields), and I have it all working, however, after editing the Run Configuration, and click "Apply" or "OK" after changing values, the entered values are lost.
What is the correct way to persist and read-back values (both when the Run Configuration is re-opened as well as when the Run Configuration's Runner invoked)? It looks like I could try to create a custom persistence using [2], however, it seems like the Plugin framework should have a way to handle this already or at least hooks for when Apply/OK is pressed.
[1] https://www.jetbrains.org/intellij/sdk/docs/tutorials/run_configurations.html
[2] https://www.jetbrains.org/intellij/sdk/docs/basics/persisting_state_of_components.html
Hopefully, this post is a bit more clear to those new to IntelliJ plugin development and illustrates how persisting/loading Run Configurations can be achieved. Please read through the code comments as this is where much of the explanation takes place.
Also now that SettingsEditorImpl is my custom implementation of the SettingsEditor abstract class, and likewise, RunConfigurationImpl is my custom implementation of the RunConfigiration abstract class.
The first thing to do is to expose the form fields via custom getters on your SettingsEditorImpl (ie. getHost())
public class SettingsEditorImpl extends SettingsEditor<RunConfigurationImpl> {
private JPanel configurationPanel; // This is the outer-most JPanel
private JTextField hostJTextField;
public SettingsEditorImpl() {
super();
}
#NotNull
#Override
protected JComponent createEditor() {
return configurationPanel;
}
/* Gets the Form fields value */
private String getHost() {
return hostJTextField.getText();
}
/* Copy value FROM your custom runConfiguration back INTO the Form UI; This is to load previously saved values into the Form when it's opened. */
#Override
protected void resetEditorFrom(RunConfigurationImpl runConfiguration) {
hostJTextField.setText(StringUtils.defaultIfBlank(runConfiguration.getHost(), RUN_CONFIGURATION_HOST_DEFAULT));
}
/* Sync the value from the Form UI INTO the RunConfiguration which is what the rest of your code will interact with. This requires a way to set this value on your custom RunConfiguration, ie. RunConfigurationImpl##setHost(host) */
#Override
protected void applyEditorTo(RunConfigurationImpl runConfiguration) throws ConfigurationException {
runConfiguration.setHost(getHost());
}
}
So now, the custom SettingsEditor, which backs the Form UI, is set up to Sync field values In and Out of itself. Remember, the custom RunConfiguration is what is going to actually represent this configuration; the SettingsEditor implementation just represents the FORM (a subtle difference, but important).
Now we need a custom RunConfiguration ...
/* Annotate the class with #State and #Storage, which is used to define how this RunConfiguration's data will be persisted/loaded. */
#State(
name = Constants.PLUGIN_NAME,
storages = {#Storage(Constants.PLUGIN_NAME + "__run-configuration.xml")}
)
public class RunConfigurationImpl extends RunConfigurationBase {
// Its good to 'namespace' keys to your component;
public static final String KEY_HOST = Constants.PLUGIN_NAME + ".host";
private String host;
public RunConfigurationImpl(Project project, ConfigurationFactory factory, String name) {
super(project, factory, name);
}
/* Return an instances of the custom SettingsEditor ... see class defined above */
#NotNull
#Override
public SettingsEditor<? extends RunConfiguration> getConfigurationEditor() {
return new SettingsEditorImpl();
}
/* Return null, else we'll get a Startup/Connection tab in our Run Configuration UI in IntelliJ */
#Nullable
#Override
public SettingsEditor<ConfigurationPerRunnerSettings> getRunnerSettingsEditor(ProgramRunner runner) {
return null;
}
/* This is a pretty cool method. Every time SettingsEditor#applyEditorTo() is changed the values in this class, this method is run and can check/validate any fields! If RuntimeConfigurationException is thrown, the exceptions message is shown at the bottom of the Run Configuration UI in IntelliJ! */
#Override
public void checkConfiguration() throws RuntimeConfigurationException {
if (!StringUtils.startsWithAny(getHost(), "http://", "https://")) {
throw new RuntimeConfigurationException("Invalid host");
}
}
#Nullable
#Override
public RunProfileState getState(#NotNull Executor executor, #NotNull ExecutionEnvironment executionEnvironment) throws ExecutionException {
return null;
}
/* This READS any prior persisted configuration from the State/Storage defined by this classes annotations ... see above.
You must manually read and populate the fields using JDOMExternalizerUtil.readField(..).
This method is invoked at the "right time" by the plugin framework. You dont need to call this.
*/
#Override
public void readExternal(Element element) throws InvalidDataException {
super.readExternal(element);
host = JDOMExternalizerUtil.readField(element, KEY_HOST);
}
/* This WRITES/persists configurations TO the State/Storage defined by this classes annotations ... see above.
You must manually read and populate the fields using JDOMExternalizerUtil.writeField(..).
This method is invoked at the "right time" by the plugin framework. You dont need to call this.
*/
#Override
public void writeExternal(Element element) throws WriteExternalException {
super.writeExternal(element);
JDOMExternalizerUtil.writeField(element, KEY_HOST, host);
}
/* This method is what's used by the rest of the plugin code to access the configured 'host' value. The host field (variable) is written by
1. when writeExternal(..) loads a value from a persisted config.
2. when SettingsEditor#applyEditorTo(..) is called when the Form itself changes.
*/
public String getHost() {
return host;
}
/* This method sets the value, and is primarily used by the custom SettingEditor's SettingsEditor#applyEditorTo(..) method call */
public void setHost(String host) {
this.host = host;
}
}
To read these configuration values elsewhere, say for example a custom ProgramRunner, you would do something like:
final RunConfigurationImpl runConfiguration = (RunConfigurationImpl) executionEnvironment.getRunnerAndConfigurationSettings().getConfiguration();
runConfiguration.getHost(); // Returns the configured host value
See com.intellij.execution.configurations.RunConfigurationBase#readExternal as well as com.intellij.execution.configurations.RunConfigurationBase#loadState and com.intellij.execution.configurations.RunConfigurationBase#writeExternal
I have a custom launch configuration. It currently has a JavaArgumentsTab() where I can enter things for VM arguments and Program arguments. But how do I actually get any values entered there?
Ideally I would get them inside my LaunchConfigurationDelegate's launch() method. I expected to find any text entered as arguments inside the LaunchConfiguration or other parameters to that method, and I'm sure this is a newbie question, but I really haven't found anything promising.
TabGroup:
public class LaunchConfigurationTabGroup extends AbstractLaunchConfigurationTabGroup {
#Override
public void createTabs(ILaunchConfigurationDialog dialog, String mode) {
ILaunchConfigurationTab[] tabs = new ILaunchConfigurationTab[] {
new JavaArgumentsTab(),
new CommonTab()
};
setTabs(tabs);
} }
LaunchConfigurationDelegate:
public class LaunchConfigurationDelegate implements ILaunchConfigurationDelegate {
#Override
public void launch(ILaunchConfiguration configuration, String mode,
ILaunch launch, IProgressMonitor monitor) throws CoreException {
// How to get anything entered on my Java tab here...?
} }
Everything from the tabs should already have been set as attribute values in the ILaunchConfiguration when launch is called.
The settings from JavaArgumentsTab are stored in the attributes using constants from IJavaLaunchConfigurationConstants.
I want to make an application in javaFX 2 which opens as a smaller login window, then, when you put in correct data, it takes you to bigger main window. Both are designed in fxml and events are handled within java code.
Yes, I know, it is almost the same as the application in samples and I've tried to do what I want and it worked there.
Now, when I did the same in my project, I hit a problem when I want to change the value of stage.
As you can see in the code below, I have global variable and I set the value of primaryStage in start method to it. Just as a test, I print it out at end of start method and the value is set.
Then, when I try to use it when button is clicked(method buttonClick), the value of stage variable is null, therefore I cannot use it to resize window or anything else.
My question is why is stage variable value reseted despite that I don't use change anything between the two prints?
This code is sample of what I've tried, I've just cut out all code which is not crucial to understand how my application works.
public class App extends Application {
private Stage stage;
#FXML
private AnchorPane pane;
#Override
public void start(Stage primaryStage) {
try {
stage = primaryStage; // Set the value of primaryStage to stage
primaryStage.setScene(new Scene(openScene("Login"))); // Load Login window
primaryStage.show(); // Show the scene
} catch (IOException ex) {
Logger.getLogger(App.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println(stage);// <-- Here it has the value of primaryStage obviously
}
#FXML
void buttonClick(ActionEvent event) throws IOException {
// Note that even if I try to print here, the value of stage is still
// null, so the code doesn't affect it
// Also, this loads what I want, I just can't change the size.
try{
pane.getChildren().clear(); // Clear currently displayed content
pane.getChildren().add(openScene("MainScene")); // Display new content
System.out.println(stage); // <-- Here, output is null, but I don't know why
stage.setWidth(500); // This line throws error because stage = null
} catch (IOException ex) {
Logger.getLogger(App.class.getName()).log(Level.SEVERE, null, ex);
}
}
public Parent openScene(String name) throws IOException {
//Code from FXML login example
Parent parent = (Parent) FXMLLoader.load(PrijavnoOkno.class.getResource(name
+ ".fxml"), null, new JavaFXBuilderFactory());
return parent;
}
public static void main(String[] args) {
launch(args);
}
}
Although it is not clear by whom and where the buttonClick action method is called, I pressume it is a login button's action in Login.fxml. Also I assume you have defined the App (a.k.a PrijavnoOkno) as a controller of this Login.fxml.
According to these assumptions, there are 2 instances of App.class:
one created when the app starts up and where the stage variable is assigned with primary stage in start() method,
and another instance created by FXMLLoader (while loading Login.fxml) and where the stage variable is not assigned and thus NPE.
One of the right ways can be, create a new Controller class for Login.fxml, call your login action in it. Access the global stage (by making it static in App) from there.
I have a small piece of code that should compile and allow the user to input a figure in the terminal window ( I am using Blue J).
However, while it does 'compile', I can never open, view or interact with the terminal window. I am met with a red "object box" instead.
I have been trying for a while to get around this problem and I can't seem to find the answer anywhere.
Here is the code used:
import java.util.Scanner;
public class PartA
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.println("Input your message: "); //this is the user promot
String message = input.nextLine();
System.out.println(message);
}
}
I've figured out the answer to this problem since posting.
While I was clicking on new PartA() to view the program in the terminal window, this only created an object (the red box). By clicking on public static void main(String[] args) (essentially a method as opposed to an object) I was able to view, and interact with the terminal window.
I´m writing on an service to watch for the existence different files in diffent folders...
I´m using filesystemwatchers to get the events.
As a part of the deployment one of the watched folders is deleted and new created from time to time.
As a result the service throws an error and is stopped...
Is it possible to catch that kind of error and recreate the filewatcher on the new folder by the service?
Catch the deleted event, and then reschedule with timed poll to watch a new one?
I don't have a compiler to hand right now but I knocked up this pseudo code:
using System;
using System.IO;
public class Watcher : IDisposable{
void Dispose(){ watcher.OnDeleted -= onDelete; }
string file;
FileSystemWatcher watcher;
FileSystemEventHandler onDelete;
public class Watch(string file, FileSystemEventHandler onDelete) {
this.file = file;
watcher = new FileSystemWatcher{ Path = file }
this.OnDelete = onDelete;
watcher.Deleted += onDelete;
watcher.NotifyFilter = ...; // looking for delete event;
// Begin watching.
watcher.EnableRaisingEvents = true;
}
}
public static class watch {
Watcher watcher;
public static void Main() {
watcher = new Watcher("somedir", ondeleted);
SetUpChangeWatchers();
while(true){
// stuff!
}
CleanUpChangeWatchers();
}
private static void ondeleted(object source, RenamedEventArgs e){
CleanUpChangeWatchers();
watcher.Dispose();
while(!directoryRecreated(file)){
Thread.Sleep(...some delay..);
}
SetUpChangeWatchers();
watcher = new Watcher("somedir", ondeleted);
}
}
You can handle this with the .deleted event. However, if you delete the directory assigned to the filesystemwatcher.Path, it may cause an error. One way around this is to assign the parent of the watched directory to filesystemwatcher.Path. Then it should catch the deletion in the .deleted event.
It is also possible to have an error inside the handler if you try to access the directory just deleted. When this happens, you may not get the normal breakpoint and it seems like it's caused by the deletion itself.