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It seems my IntelliJ cannot find my csv file? [closed]

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So ive made a class to keep track of the data i've imported:
package com.company;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class ImportData {
public ImportData() {
}
public static ArrayList<Pizza> readData() throws IOException{
String file = "Users/mathiaspoulsen/Desktop/SP3MarioPizza/pizzas.csv";
ArrayList <Pizza> content = new ArrayList<>();
try(BufferedReader br = new BufferedReader(new FileReader(file))) {
String line = br.readLine();
while ((line = br.readLine()) != null) {
line = br.readLine();
String [] lineArr = line.split(",");
Pizza pizza = new Pizza (Integer.parseInt(lineArr[0]),lineArr[1],Double.parseDouble(lineArr[2]));
content.add(pizza);
}
} catch (FileNotFoundException e) {
//Some error logging
}
return content;
}
I have then tried to run it in the main method to see if it loads the csv-file corectly. Like this:
package com.company;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
public class Main {
public static void main(String[] args) throws IOException {
/* int i = 0;
String fileName = "pizzas.csv";
Path pathToFile = Paths.get(fileName);
System.out.println(pathToFile.toAbsolutePath());
*/
// ArrayList<Pizza> pizzas = ImportData.readData();
System.out.println(ImportData.readData());
}
}
The output of this program is: []
Why dont it display the pizzas? The pizzas in the csv-file a structured like this:
PizzaNumber(int),PizzaName(String), price(double)
1,MARGHERITA,69.00

You read the line multiple times which most likely was causing your issue just read the line once and check to make sure it is not null in the while statement before parsing it. Also, it would be better to check to make sure the parse is successful.
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class ImportData {
public ImportData() {
}
public static ArrayList<Pizza> readData() throws IOException {
String file = "/Users/your/path/pizza.csv";
ArrayList<Pizza> content = new ArrayList<>();
try (BufferedReader br = new BufferedReader(new FileReader(file))) {
String line;
while ((line = br.readLine()) != null) {
String[] lineArr = line.split(",");
content.add(new Pizza(Integer.parseInt(lineArr[0]), lineArr[1], Double.parseDouble(lineArr[2])));
}
}
catch (FileNotFoundException e) {
System.out.println(e);
}
return content;
}
}

Is my HashSet deleting a column in my output csv file?

So everything is showing correctly in my Java IDE and runs as it should. I have it where the data automatically writes to the csv file every few minutes. The problem I'm having is that the "Meter 2" column is not showing up and I have a feeling that the HashSet in my code might think that it's a duplicate and deleting it.
Here's the code:
package HourMeter;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
public class Hours {
Set<String> hour = new HashSet<>();
String filename;
/**
* #param filename filename of the .csv file to update
* #param addresses Array of Strings of addresses to add to the .csv file
* #throws IOException Throws exception on incorrect filename
*/
public Hours(String filename, String[] addresses) throws IOException {
if(filename==null) throw new IllegalArgumentException();
this.filename = filename;
try (BufferedReader reader = new BufferedReader(new
FileReader("Hours.csv"))) {
while(reader.ready())
{
hour.add(reader.readLine());
}
}
if(addresses != null)
{
hour.addAll(Arrays.asList(addresses));
}
}
Hours(String string) {
throw new UnsupportedOperationException("Not supported yet."); //To
change body of generated methods, choose Tools | Templates.
}
public void outputFile() throws IOException
{
try (PrintWriter out = new PrintWriter("Hours.csv")) {
hour.forEach((s) -> {
out.println(s);
});
}
}
}
Below is a photo of the program and the csv report.
As you can see, the csv report is missing a set of string values, meter 2. What should I think about doing or changing in my code to make this show in the csv report? Thanks for the help. I have been trying to figure this out for a few days now. Any help would be greatly appreciated!

List attached devices on ubuntu in java

I'm a little stumped, currently I am trying to list all of the attached devices on my system in linux through a small java app (similar to gparted) I'm working on, my end goal is to get the path to the device so I can format it in my application and perform other actions such as labels, partitioning, etc.
I currently have the following returning the "system root" which on windows will get the appropriate drive (Ex: "C:/ D:/ ...") but on Linux it returns "/" since that is its technical root. I was hoping to get the path to the device (Ex: "/dev/sda /dev/sdb ...") in an array.
What I'm using now
import java.io.File;
class ListAttachedDevices{
public static void main(String[] args) {
File[] paths;
paths = File.listRoots();
for(File path:paths) {
System.out.println(path);
}
}
}
Any help or guidance would be much appreciated, I'm relatively new to SO and I hope this is enough information to cover everything.
Thank you in advance for any help/criticism!
EDIT:
Using part of Phillip's suggestion I have updated my code to the following, the only problem I am having now is detecting if the selected file is related to the linux install (not safe to perform actions on) or an attached drive (safe to perform actions on)
import java.io.File;
import java.io.IOException;
import java.nio.file.FileStore;
import java.nio.file.FileSystems;
import java.util.ArrayList;
import javax.swing.filechooser.FileSystemView;
class ListAttachedDevices{
public static void main(String[] args) throws IOException {
ArrayList<File> dev = new ArrayList<File>();
for (FileStore store : FileSystems.getDefault().getFileStores()) {
String text = store.toString();
String match = "(";
int position = text.indexOf(match);
if(text.substring(position, position + 5).equals("(/dev")){
if(text.substring(position, position + 7).equals("(/dev/s")){
String drivePath = text.substring( position + 1, text.length() - 1);
File drive = new File(drivePath);
dev.add(drive);
FileSystemView fsv = FileSystemView.getFileSystemView();
System.out.println("is (" + drive.getAbsolutePath() + ") root: " + fsv.isFileSystemRoot(drive));
}
}
}
}
}
EDIT 2:
Disregard previous edit, I did not realize this did not detect drives that are not already formatted

Following Elliott Frisch's suggestion to use /proc/partitions I've come up with the following answer. (Be warned this also lists bootable/system drives)
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
class ListAttachedDevices{
public static void main(String[] args) throws IOException {
ArrayList<File> drives = new ArrayList<File>();
BufferedReader br = new BufferedReader(new FileReader("/proc/partitions"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while (line != null) {
String text = line;
String drivePath;
if(text.contains("sd")){
int position = text.indexOf("sd");
drivePath = "/dev/" + text.substring(position);
File drive = new File(drivePath);
drives.add(drive);
System.out.println(drive.getAbsolutePath());
}
line = br.readLine();
}
} catch(IOException e){
Logger.getLogger(ListAttachedDevices.class.getName()).log(Level.SEVERE, null, e);
}
finally {
br.close();
}
}
}

Delete a line from a text file by overwriting using arrays to store the lines of a text file

I need done in the most simplest way possible..... And where have I gone wrong here....
This is my code so far...
import java.io.*;
class test
{
public static void main()throws IOException
{
FileReader f=new FileReader("g.txt");
BufferedReader in=new BufferedReader(f);
PrintWriter p=new PrintWriter(new BufferedWriter(new FileWriter("g.txt")));
String ar[]=new String[5];
String text;int i=0;
while((text=in.readLine())!=null)
{
ar[i]=text;
i++;
}
i=0;
for(i=0;i<ar.length;i++)
{
if(ar[i].equals("the da vinci code"))
{
ar[i]=null;
break;
}
}
for(int j=0;j<ar.length;j++)
{
System.out.println(ar[j]);
p.println(ar[i]);
}
in.close();
p.close();
}
}

Here is one way though better is to write to another file as you read from this, have a try -catch and close the file handles in the finally, use logging ...
package files;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;//growing array
class ReadFileRemoveLines// class test is a bad name
{
public static void main(String[]args)throws IOException//need to follow the signature or cant start the program
{
FileReader f=new FileReader("g.txt");
BufferedReader in=new BufferedReader(f);
ArrayList<String> ar = new ArrayList<String>(5);//initial size if you expect so many lines or leave out the 5 ()
String text;int i=0;
while((text = in.readLine()) != null)//spaces between symbols help readability
{
//why not test test here
if(!text.equals("the da vinci code")){
ar.add(text);
}
///i++;
}
/*
i=0;
for(i=0;i<ar.length;i++)
{
if(ar[i].equals("the da vinci code"))
{
ar[i]=null;
break;
}
}*/
in.close();
PrintWriter p=new PrintWriter(new BufferedWriter(new FileWriter("g.txt")));
for(int j=0;j<ar.size();j++)
{
System.out.println(ar.get(j));
p.println(ar.get(j));//why are you printint of i loop is j
}
p.close();
}
}

Just making the underlying reference of that line null does not delete that line in that file.
You need to read the file completely.
Pick up the lines which you want and store them in a collection.
Rename or move that file(Create a backup just in case).
Write all the lines again with the same file name.

How to read MP3 file tags

I want to have a program that reads metadata from an MP3 file. My program should also able to edit these metadata. What can I do?
I got to search out for some open source code. But they have code; but not simplified idea for my job they are going to do.
When I read further I found the metadata is stored in the MP3 file itself. But I am yet not able to make a full idea of my baby program.
Any help will be appreciated; with a program or very idea (like an algorithm). :)

The last 128 bytes of a mp3 file contains meta data about the mp3 file., You can write a program to read the last 128 bytes...
UPDATE:
ID3v1 Implementation
The Information is stored in the last 128 bytes of an MP3. The Tag
has got the following fields, and the offsets given here, are from
0-127.
Field Length Offsets
Tag 3 0-2
Songname 30 3-32
Artist 30 33-62
Album 30 63-92
Year 4 93-96
Comment 30 97-126
Genre 1 127
WARINING- This is just an ugly way of getting metadata and it might not actually be there because the world has moved to id3v2. id3v1 is actually obsolete. Id3v2 is more complex than this, so ideally you should use existing libraries to read id3v2 data from mp3s . Just putting this out there.

You can use apache tika Java API for meta-data parsing from MP3 such as title, album, genre, duraion, composer, artist and etc.. required jars are tika-parsers-1.4, tika-core-1.4.
Sample Program:
package com.parse.mp3;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import org.apache.tika.exception.TikaException;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.Parser;
import org.apache.tika.parser.mp3.Mp3Parser;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
public class AudioParser {
/**
* #param args
*/
public static void main(String[] args) {
String fileLocation = "G:/asas/album/song.mp3";
try {
InputStream input = new FileInputStream(new File(fileLocation));
ContentHandler handler = new DefaultHandler();
Metadata metadata = new Metadata();
Parser parser = new Mp3Parser();
ParseContext parseCtx = new ParseContext();
parser.parse(input, handler, metadata, parseCtx);
input.close();
// List all metadata
String[] metadataNames = metadata.names();
for(String name : metadataNames){
System.out.println(name + ": " + metadata.get(name));
}
// Retrieve the necessary info from metadata
// Names - title, xmpDM:artist etc. - mentioned below may differ based
System.out.println("----------------------------------------------");
System.out.println("Title: " + metadata.get("title"));
System.out.println("Artists: " + metadata.get("xmpDM:artist"));
System.out.println("Composer : "+metadata.get("xmpDM:composer"));
System.out.println("Genre : "+metadata.get("xmpDM:genre"));
System.out.println("Album : "+metadata.get("xmpDM:album"));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (TikaException e) {
e.printStackTrace();
}
}
}

For J2ME(which is what I was struggling with), here's the code that worked for me..
import java.io.InputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;
import javax.microedition.lcdui.*;
import javax.microedition.media.Manager;
import javax.microedition.media.Player;
import javax.microedition.media.control.MetaDataControl;
import javax.microedition.midlet.MIDlet;
public class MetaDataControlMIDlet extends MIDlet implements CommandListener {
private Display display = null;
private List list = new List("Message", List.IMPLICIT);
private Command exitCommand = new Command("Exit", Command.EXIT, 1);
private Alert alert = new Alert("Message");
private Player player = null;
public MetaDataControlMIDlet() {
display = Display.getDisplay(this);
alert.addCommand(exitCommand);
alert.setCommandListener(this);
list.addCommand(exitCommand);
list.setCommandListener(this);
//display.setCurrent(list);
}
public void startApp() {
try {
FileConnection connection = (FileConnection) Connector.open("file:///e:/breathe.mp3");
InputStream is = null;
is = connection.openInputStream();
player = Manager.createPlayer(is, "audio/mp3");
player.prefetch();
player.realize();
} catch (Exception e) {
alert.setString(e.getMessage());
display.setCurrent(alert);
e.printStackTrace();
}
if (player != null) {
MetaDataControl mControl = (MetaDataControl) player.getControl("javax.microedition.media.control.MetaDataControl");
if (mControl == null) {
alert.setString("No Meta Information");
display.setCurrent(alert);
} else {
String[] keys = mControl.getKeys();
for (int i = 0; i < keys.length; i++) {
list.append(keys[i] + " -- " + mControl.getKeyValue(keys[i]), null);
}
display.setCurrent(list);
}
}
}
public void commandAction(Command cmd, Displayable disp) {
if (cmd == exitCommand) {
notifyDestroyed();
}
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
}