Jacob Morehouse

Got it, thanks Ulf Dittmer!

Hi again,


OK, I'm stumped. When I System.out.println() the text looks great and the newline/line breaks appear normally. But when I save the string to a file they all appear on one line.
public static void main(String[] args) throws IOException { String bytesToWriteString = "this\nis\na\ntest"; Files.write(Paths.get("C:\\Users\\Jacob\\Desktop\\test.txt"), bytesToWriteString.getBytes(Charset.forName("UTF-8"))); }
The newline characters just disappear. I've tried with no charset (letting in default), UTF-8, and US-ASCII. None of those made a noticeable difference. What am I doing wrong here?

Thanks,
Jake

Of course after giving up and posting, I solve it:
//First, use generics on the lists... List<Password> listPasswords = new ArrayList<>(); ObservableList<Password> obListPasswords = FXCollections.observableArrayList(listPasswords); //Now when I do that, it lets me use the methods of the Password class: for (int i=0; i<obListPasswords.size(); i++) { bytesToWriteString = bytesToWriteString + obListPasswords.get(i)[b].getPasswordContents() [/b]+ "\n"; }

And away we go! Still getting used to generics. Also, welcoming any better or more concise solutions. There's always someone out there with a better way to skin the proverbial cat.

Thanks,
Jake

Hello!


This is probably an easy one, but for some reason my searches turn up nothing. I'm possibly Googling this wrong? Anywho, here's my code:
//obListPasswords is an observable list that contains objects for (int i=0; i<obListPasswords.size(); i++) { bytesToWriteString = bytesToWriteString + obListPasswords.get(i) + "\n"; }

This results in references to those objects, like "passwordgeneratorfx.Password@41b192cc." I've given the Password class a method of "getPaswordContents" that returns a string value, but I cannot seem to reference it here. How would I call that method here on each object in the list?

Thanks,
Jake

Thank you John! I tried it so many different ways and never thought to change the file type. I tested with a .png and of course it worked perfectly.

Thank you so much for the detailed and thorough reply, very appreciated.


Jake

Hello!


I'm a bit new to Java and JavaFX, so I'm sure this is an easy fix. First the context - I've written a program to list TIFF files and make them viewable in a little popup window. Here is the code for that window:
//localImagePath is something like: "C:\ProgramFiles\ImageViewer\someTiff.tif" Image theImage = new Image("file:" + localImagePath.toString()); ImageView theImageView = new ImageView(theImage); Stage viewImageStage = new Stage(); Group imageGroup = new Group(); Scene imageScene = new Scene(imageGroup); imageGroup.getChildren().add(theImageView); viewImageStage.setScene(imageScene); viewImageStage.setTitle("Image: "); viewImageStage.setWidth(500); viewImageStage.setHeight(500); viewImageStage.sizeToScene(); viewImageStage.show();

When the new stage appears it is completely empty. I've spent a bit of time on this and I think my problem lies in one of two places: I have specified the file path incorrectly (though this is the only variation that doesn't throw an exception), OR I have incorrectly formed the UI components and something isn't attaching to the scene/stage.

Even if someone can tell me definitively which of the two it is it would be a great help, then I'm only diving down one rabbit hole...

Thanks!
Jake

Hi Ritesh,

You have a couple things going on, I'll try to walk you through. First, spacing is goofy... makes it hard to for you to debug (using NetBeans, alt+shift+f will fix spacing).

This can't exist here, can't instantiate an object of the class from within the class:
static Month m=new Month();{

You have to put that code in the main, like this:

class Month { Month(){ System.out.println("hi"); m1(); } static void m1(){ System.out.println("hi from m1"); } public static void main(String[] arg){ System.out.println("hi from main"); Month m=new Month(); } }

Hope that helps,

Jake

Hi ven,


Great question! A constructor is not really in use until it is called to construct an object, in which case the "this" keyword would point to that object. For example you might make a method in a class that absorbs input from an XML file, but just because that XML data doesn't exist at compile time doesn't mean there is a problem. The constructer only "constructs" when an object is instantiated: myObject something = new MyObject();

Home that helps.

Jake

Darryl Burke wrote:

Jacob Morehouse wrote:Got it. In case anyone else Googles it and finds this post. It had nothing to do with generics, everything to do with objects/classes.

If you Googled and got here, hopefully you'll read the entire thread and follow any links to learning resources, from which you will conclude that this has everything to do with Generics.

You found your post not to be vague? I understand how your feelings might be a little bruised here, but a post like your first one holds very little value not because you were incorrect, but because you made no effort to support your claim. I realize your attempt was to get me to look up generics, but a comment like yours on the Internet just gets immediately ignored as another troll. A comment like K. Tsnag's gets me looking up generics.

K. Tsang wrote:Hi Jacob

In fact changing your code to use array is one solution, but using generics can surely make life easier for large collections.
ArrayList<People> peopleList = new ArrayList<People>(); // this will print Jake because peopleList.get(0) is a People class instead of Object class System.out.println(peopleList.get(0).getName());

Thank you for posting - I would consider your solution superior as well, you don't have to define the exact length of the array which is also good.

To verify I understand, <People> is casting the "type" of the array to "People"?

Jake

Got it. In case anyone else Googles it and finds this post. It had nothing to do with generics, everything to do with objects/classes. I changed my main:
package test1; import java.util.ArrayList; public class Test1 { public static void main(String[] args) { People jake = new People("jake"); People[] arrayPeople = new People[10]; //an array of people, with 10 positions arrayPeople[0] = jake; //set position 0 to the "jake" object System.out.println(arrayPeople[0].name); //display the .name property of the "jake" object. } }
If you Googled and got here, hopefully you didn't waste time on generics on your way to my answer.


Jake

Thanks Bear, moving in the right direction now.

Hi Darryl,


I'll take from your vague post that this forum isn't friendly to entry level questions. Is there another forum (or site entirely) you would recommend I post this question? I feel like we're already off to a trolled start and neither of us is adding value to this forum at this point.


Thanks

Hello!


I've done this before, I cannot figure out what I am missing. In short, I can access an objects methods (like gets and sets) while it is just an object, but when I put it into a structure like an ArrayList I cannot access those methods.

The class:
package test1; public class People { String name = ""; //constructor public People(String inName) { name = inName; } //getter public String getName() { return name; } }

Now the main:
package test1; import java.util.ArrayList; public class Test1 { public static void main(String[] args) { People jake = new People("jake"); //At this level it works, I can access the "name" property ArrayList people_list = new ArrayList(); people_list.add(jake); System.out.println(people_list.get(0).getName()); //error here - .getName() is not recognized } }

It has been awhile since I've done anything with Java, what am I doing wrong here? I'm sure it is something simple but I'm about 6 hours in and still no solution. Any help would be appreciated.

Thanks!
Jake

Thank you Janeice, that did the trick. You are correct. It didn't immediately click what that meant, but as I looked it over it makes sense. In case anyone else get's stuck, the corrected version of my code is below.


Daragaaz

import java.awt.GridBagLayout; import java.awt.GridBagConstraints; import java.awt.Dimension; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import java.awt.*; import javax.swing.JButton; import javax.swing.JLabel; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; public class haakon_calc_main extends JFrame implements ActionListener { JPanel the_panel = new JPanel(new GridBagLayout()); static int weight = 0; static int freight = 0; static int surcharge = 0; static int fsc = 0; static int the_total = 0; JLabel weight_label = new JLabel("Weight: "); JTextField weight_field = new JTextField(5); JLabel spacer_label = new JLabel(" "); JLabel freight_label = new JLabel("Freight: "); JTextField freight_field = new JTextField(5); JLabel surcharge_label = new JLabel("Surcharge: "); JTextField surcharge_field = new JTextField(5); JLabel fsc_label = new JLabel("FSC: "); JTextField fsc_field = new JTextField(5); JLabel vertspace_label = new JLabel(" "); JButton calculate_button = new JButton("Calculate"); JLabel total_label = new JLabel("Total: "); JTextField total_field = new JTextField(5); //build window public haakon_calc_main() { //define frame super("Haakon Calculator"); setSize(370, 250); setResizable(false); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setLocationRelativeTo(null); GridBagConstraints gbc = new GridBagConstraints(); //gbc.fill = GridBagConstraints.HORIZONTAL; gbc.insets = new Insets(3,3,3,3); gbc.anchor = GridBagConstraints.WEST; //gbc.weightx = 0.5; gbc.gridx = 0; gbc.gridy = 0; the_panel.add(weight_label, gbc); gbc.gridx = 1; gbc.gridy = 0; the_panel.add(weight_field, gbc); spacer_label.setPreferredSize(new Dimension(60,1)); gbc.gridx = 2; gbc.gridy = 0; the_panel.add(spacer_label, gbc); gbc.gridx = 3; gbc.gridy = 1; the_panel.add(freight_label, gbc); gbc.gridx = 4; gbc.gridy = 1; the_panel.add(freight_field, gbc); gbc.gridx = 3; gbc.gridy = 2; the_panel.add(surcharge_label, gbc); gbc.gridx = 4; gbc.gridy = 2; the_panel.add(surcharge_field, gbc); gbc.gridx = 3; gbc.gridy = 3; the_panel.add(fsc_label, gbc); gbc.gridx = 4; gbc.gridy = 3; the_panel.add(fsc_field, gbc); gbc.gridx = 0; gbc.gridy = 4; the_panel.add(vertspace_label, gbc); gbc.gridwidth = 2; gbc.gridx = 0; gbc.gridy = 5; the_panel.add(calculate_button, gbc); gbc.gridwidth = 2; gbc.gridx = 2; gbc.gridy = 5; the_panel.add(total_label, gbc); gbc.gridwidth = 2; gbc.gridx = 3; gbc.gridy = 5; the_panel.add(total_field, gbc); //add panels to frame getContentPane().add(the_panel,BorderLayout.NORTH); //set the listeners calculate_button.addActionListener(this); } public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub if (e.getSource() == calculate_button) { //do things... } } public static void main(String[] args) { new haakon_calc_main().setVisible(true); } }