I know this question has been asked before, but I have a slightly different problem.
I want to read and write to a text file which will be included in my build(.jar file) . its a Gui application java.
Where Should I place the file?
I have placed the file by creating a new Resources folder under the project. This enables me to read the file but when I attempt to write to it, it throws a FileNotFound Exception. What should I do?
I am using this code
File file = new File(this.getClass().getClassLoader().getResource("score.txt").getFile());
FileOutputStream stream = new FileOutputStream(file);
DataOutputStream write = new DataOutputStream(stream);
write.writeInt(max);
And for Input i use this :
File file = new File(this.getClass().getClassLoader().getResource("Files/score.txt").getFile());
FileInputStream input = new FileInputStream(file);
DataInputStream read = new DataInputStream(input);
System.out.println(read.readInt());
For reading this code works perfectly.
I am trying to write a .txt file in a resource folder but it doesn't write anything. I am able to read the same .txt file by doing:
Scanner scanner = null;
InputStream IS = MyClass.class.getResourceAsStream("/File/My FileH");
scanner = new Scanner(IS);
But when it comes to write, I have tried doing:
PrintWriter writer = new PrintWriter(
new File(this.getClass().getResource("/File/My FileH").getFile()));
writer.println("hello");
writer.close();
Any suggestions on how to write in that folder?
You can't write something in to a resource, assume that you packed your resource as a jar. Jar is only read only. You can't update that. Either you can extract the jar and edit the contents.
You can try Preferences as an alternative
I'm using Netbeans and in my program I'm reading a file. When I run the program it reads the file correctly. When I build the program the JAR also works correctly. But when I change the file that I am reading from, in my build dir, my JAR doesn't update accordingly. Why is that so? Is there a solution for this?
The code below shows how am I reading the file in my program. Thanks in advance.
InputStream in = NewJFrame.class.getResourceAsStream("/holidays.txt");
BufferedReader readHolidays = new BufferedReader(new InputStreamReader(in));
String line;
line = readHolidays.readLine();
while(line != null) {
//read into hashmaps
//...
line = readHolidays.readLine();
}
readHolidays.close();
Never mind, i got it ;) If anyone else needs this: Basically every time i run the program i find the file path to the jar file and from there i read text document.
File jarFile = new File(this.getClass().getProtectionDomain().getCodeSource().getLocation().toURI());
FileInputStream is = new FileInputStream(jarFile.getParent().toString() + "/file.txt"); BufferedReader readFile= new BufferedReader(new InputStreamReader(is));
Why is Printwriter doing this?
File file = new File("/files/KA.txt");
writer = new PrintWriter(file);
writer.write("HELLO");
In the above code I keep getting an error that says :
java.io.FileNotFoundException: \files\KA.txt (The network path was not found)
Except this was not my specified path? How do I then specify a file to write - usually create a new file and write to this? It also throws errors if KA.txt is not present - I ideally want to create a new file and writer to it.
Thanks
I ideally want to create a new file and writer to it.
You can simply create a file ,
PrintWriter writer = new PrintWriter("name.txt", "UTF-8");
writer.println("text");
where UTF-8 is the file encoding. and write to the file , remember it overrides if the file exists with the same name
The problem is that the parent /files directory doesn't already exist, so you must create it beforehand, using File.mkdirs.
File file = new File("/files/KA.txt");
File parentFile = file.getParentFile();
parentFile.mkdirs();
PrintWriter writer = new PrintWriter(file);
writer.write("HELLO");
writer.close();
I can read texts and write them to console however when i install this application to another computer wherever it is installed I dont want to change the path of the txt file. I want to write it like
BufferedReader in = new BufferedReader(new FileReader("xxx.txt"));
I don't want to:
BufferedReader in = new BufferedReader(new FileReader("C:\\Users\\abcde\\Desktop\\xxx.txt"));
is there any way to show this txt file? By the way I put this txt file inside the sources but it cant read!
First get the default application path then check if file exist if exist continue if not close application.
String path = System.getProperty("user.dir");
System.out.println(path + "\\disSoruCevap.txt");
File file = new File(path + "\\disSoruCevap.txt");
if (!file.exists()) {
System.out.println("System couldnt file source file!");
System.out.println("Application will explode");
}
EDIT*
Please prefer one of the answer using resource streams, as you will
see from comments using user.dir is not safe in every case.
You are looking for :
BufferedReader in = new BufferedReader(getClass().getResourceAsStream("/xxx.txt"));
This will load xxx.txt from your jar file (or any jar file in your class path that has that file inside its root directory).
URL fileURL= yourClassName.class.getResource("yourFileName.extension");
String myURL= fileURL.toString();
now you don't need long path name PLUS this one is dynamic in nature i.e., you can now move your project to any pc, any drive.This is because it access URL by using your CLASS location not by any static location (like c:\folder\ab.mp3, then you can't access that file if you move to D drive because then you have to change to D:/folder/ab.mp3 manually which is static in nature)(NOTE: just keep that file with your project)
You can use fileURL as: File file=new File(fileURL.toURI());
You can use myURL as: Media musicFile=new Media(myURL); //in javaFX which need string not url of file
InputStream input = Class_name.class.getResourceAsStream("/xxx.txt");
InputStreamReader inputReader = new InputStreamReader(input);
BufferedReader br = new BufferedReader(inputReader);
String line = null;
try {
while((line = br.readLine())!=null){
System.out.println(line);
}
} catch (IOException ex) {
ex.printStackTrace();
}
You don't need to write or mention long path. Using this code Class_name.class.getResourceAsStream("/xxx.txt"), you can easily get your file.
BufferedReader in = new BufferedReader(new FileReader("xxx.txt")); works fine because when you run your application on an IDE, xxx.txt apparantly is lying in Java's working directory.
Working directory is an operating system feature and it can not be changed.
There are a few ways to deal with this.
1 - use file constructor new File(parent, filename); and load parent using a public static final constant or a property (either passed from command line or otherwise)
2 - or use InputStream in = YourClass.class.getClassLoader().getResourceAsStream("xxx.txt"); - provided your xxx.txt file is packaged under same location as YourClass
Try:
InputStream is = ClassLoader.getSystemResourceAsStream("xxx.txt");
BufferedReader in = new BufferedReader(new InputStreamReader(is));
Depending on where exactly is your file compared to the root of your classpath, you may have to replace xxx.txt3 with /xxx.txt.
My file paths are like this:
public final static String COURSE_FILE_LOCATION = "src/main/resources/courses.csv";
public final static String PREREQUISITE_FILE_LOCATION = "src/main/resources/prerequisites.csv";
This doesn't work. So I delete the .iml file, .idea and target folder from the project and reload them.
Read the correct path like this:
This would work then.