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Accessing a file in a runnable JAR [duplicate]

This question already has answers here:
Java resource as File
(6 answers)
Closed 9 years ago.
What I am attempting to do is store a text file (that won't change) inside the JAR of the program so that it can be read. The purpose of the text file is that it will be read in by one of my classes and the contents of the text file will be added to an JEditorPane. The file will basically be a tutorial and when the user clicks on the option to read the tutorial, the file contents will be read and displayed in a new window that pops up.
I have the GUI portion of it down, but as far as storing the file in the JAR so it can be accessed, I am at a lost. I've read that using an InputStream will work, but after trying a few things I haven't gotten it to work yet.
I also store images in the JAR to be used as icons for the GUI windows. This is accomplished with:
private Image icon = new ImageIcon(getClass()
.getResource("resources/cricket.jpg")).getImage();
But, this doesn't work when trying to get a file:
private File file = new File(getClass.getResource("resources/howto.txt"));
Here is my Class as it is now:
public class HowToScreen extends JFrame{
/**
*
*/
private static final long serialVersionUID = -3760362453964229085L;
private JEditorPane howtoScreen = new JEditorPane("text/html", "");
private Image icon = new ImageIcon(getClass().getResource("resources/cricket.jpg")).getImage();
private BufferedReader txtReader = new BufferedReader(new InputStreamReader(getClass().getResourceAsStream("/resources/howto.txt")));
public HowToScreen(){
setSize(400,300);
setLocation(500,200);
setTitle("Daily Text Tutorial");
setIconImage(icon);
howtoScreen.setEditable(false);
howtoScreen.setText(importFileStream());
add(howtoScreen);
setVisible(true);
}
public String importFile(){
String text = "";
File file = new File("howto.txt");
Scanner in = null;
try {
in = new Scanner(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
while(in.hasNext()){
text += in.nextLine();
}
in.close();
return text;
}
public String importFileStream(){
String text = "";
Scanner in = new Scanner(txtReader);
while(in.hasNext()){
text += in.nextLine();
}
in.close();
return text;
}
}
Ignore the importFile method as that is being removed in favor of storing the tutorial file inside the JAR, making the program wholly self contained as I am limited to how much space the program can use.
EDIT:
After trying all of the suggestions below, I checked to see if my JAR is packaging the text file in it and it is not. When opening the JAR with 7zip, in my resources folder the picture I use for icons is there, but not the text file.

You cannot use File inside a JAR file. You need to use InputStream to read the text data.
BufferedReader txtReader = new BufferedReader(new InputStreamReader(getClass().getResourceAsStream("/resources/mytextfile.txt")));
// ... Use the buffered reader to read the text file.

Try the next (with the full path package):
InputStream inputStream = ClassLoader.getSystemClassLoader().
getSystemResourceAsStream("com/company/resources/howto.txt");
InputStreamReader streamReader = new InputStreamReader(inputStream, "UTF-8");
BufferedReader in = new BufferedReader(streamReader);
for (String line; (line = in.readLine()) != null;) {
// do something with the line
}

You code will not compile. Class.getResource() returns a URL, and File has no constructor with a URL as an argument.
You can just use .getResourceAsStream() instead, it returns an InputStream directly, you just have to read the contents of the file from that stream.
Note: both of these methods return null if the resource is not found: don't forget to check for that...

the contents of the text file will be added to an JEditorPane.
See DocumentVewer & especially JEditorPane.setPage(URL).
Since the help is an embedded-resource it will be necessary to gain an URL using getResource(String) as detailed in the info. page.
.. tried this: URL url = this.getClass().getResource("resources/howto.txt");
Change:
URL url = this.getClass().getResource("resources/howto.txt");
To:
URL url = this.getClass().getResource("/resources/howto.txt"); // note leading '/'

Read bytes from file Java

I'm trying to parse my file which keeps all data in binary form. How to read N bytes from file with offset M? And then I need to convert it to String using new String(myByteArray, "UTF-8");. Thanks!
Here's some code:
File file = new File("my_file.txt");
byte [] myByteArray = new byte [file.lenght];
UPD 1: The answers I see are not appropriative. My file keeps strings in byte form, for example: when I put string "str" in my file it actually prints smth like [B#6e0b... in my file. Thus I need to get from this byte-code my string "str" again.
UPD 2: As it's found out the problem appears when I use toString():
PrintWriter writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(System.getProperty("db.file")), true), "UTF-8")));
Iterator it = storage.entrySet().iterator();//storage is a map<String, String>
while (it.hasNext()){
Map.Entry pairs = (Map.Entry)it.next();
String K = new String(pairs.getKey().toString());
String V = new String(pairs.getValue().toString);
writer.println(K.length() + " " + K.getBytes() + " " + V.length() + " " + V.getBytes());//this is just the format I need to have in file
it.remove();
}
May be there're some different ways to perform that?

As of Java 7, reading the whole of a file really easy - just use Files.readAllBytes(path). For example:
Path path = Paths.get("my_file.txt");
byte[] data = Files.readAllBytes(path);
If you need to do this more manually, you should use a FileInputStream - your code so far allocates an array, but doesn't read anything from the file.
To read just a portion of a file, you should look at using RandomAccessFile, which allows you to seek to wherever you want. Be aware that the read(byte[]) method does not guarantee to read all the requested data in one go, however. You should loop until either you've read everything you need, or use readFully instead. For example:
public static byte[] readPortion(File file, int offset, int length)
throws IOException {
byte[] data = new byte[length];
try (RandomAccessFile raf = new RandomAccessFile(file)) {
raf.seek(offset);
raf.readFully(data);
}
return data;
}
EDIT: Your update talks about seeing text such as [B#6e0b... That suggests you're calling toString() on a byte[] at some point. Don't do that. Instead, you should use new String(data, StandardCharsets.UTF_8) or something similar - picking the appropriate encoding, of course.

Write String to multiple txt files

The following code writes a string to a specific file.
String content = "Text To be written on a File";
File file = new File("c:/file.txt");
FileOutputStream foutput = new FileOutputStream(file);
if (!file.exists()) {
file.createNewFile();
}
byte[] c = content.getBytes();
foutput.write(c);
foutput.flush();
foutput.close();
I want to use this code in a Jbutton so every time the user clicks it, it writes the string to a NEW text file NOT OVERWRITE the existed one. I tried to do but I couldn't get the result.
Thank you in advance.

There's a couple of different ways you can get this result, it really depends on the application. The two easiest ways to do this would to be either:
Append the current timestamp to the file name
Use the File API to create a "temp file" in the directory, which is guarenteed to have a unique name
Option 1:
String baseDir = "c:/";
File newFile = new File(baseDir, "file_" + System.currentTimeMillis() + ".txt");
// do file IO logic here...
Option 2:
String baseDir = "c:/";
File newFile = File.createTempFile("file", ".txt", new File(baseDir));
// do file IO logic here...

If you want to write it to a new file, you have to create a new file. The name of the text file is always file.txt in your case.
Try this:
private int filecounter = 0; // this is the member of your class. Outside the function.
//inside your function
File file = new File("c:/file" + Integer.(filecounter).toString() + ".txt");
// you do something here.
filecounter++;
This way, your files will be stored as file0.txt, file1.txt etc.

Android getAssets.open() vs Java File method, log printing String issues

I am parsing a binary file. I didn't face any problem while doing it in java,
File file= new File("c:/xyz.bin");
DataInputStream di= new DataInputStream(new FileInputStream(file));
BufferedInputStream bin= new BufferedInputStream(dataIStream);
byte[] byteArray= new byte[bin.available()];
bin.read(byteArray);
And I am parsing the "byteArray" according to my needs using my parserClass.
Assigning the sub-bytes to different byte array members of the class "someClass", and while printing Using custom Converter to convert byte array to String.
System.out.println("Name: "+Converter.String(
someClass.getFileName()));
System.out.println("Num: "+someClass.getInteger());
Name: FILENAME
Num: 2
Everything is working fine.
But when I tried it in Android:
String fileName= "xyz.bin";
InputStream in= getAssets().open(fileName);
BufferedInputStream bin= new BufferedInputStream(new DataInputStream(in));
byte[] byteArray= new byte[bin.available()];
bin.read(byteArray);
I am using the same parser.
I am facing problem in getting the values and printing it in the log like..
String name = Converter.String(someClass.getFileName())
Log.i("File name: ", name);
Log.i("Number: ", String.valueOf(someClass.getInteger()));
This is from the log that I am getting
File name: ����������������
Number: 0
Is it because getAssets.open() treats a binary file differently? I don't see what went wrong. The only difference betwwen the two codes is, in java I am using "File" and in Android I am using "getAssets.open()" methods.

Broken Text : reading larger size text in android

i have a question about Broken text when android app is reading large size text file.
I am trying to build the app to read large size text file(about 10mb)
when I am reading a file and using System.println to check the contents of text file
However, when I display message but print statement
it displays broken text such as..
��T��h��e�� ��P��r��o��j��e��c��t�� ��G��u
when I was reading small size of rtf was find, but i used text file then i made problems
I used code like ..
String UTF8 = "utf8";
int BUFFER_SIZE = 8192;
File gone = new File(path);
FileInputStream inputStream = new FileInputStream(gone);
// FileInputStream inputStream = openFileInput(gone);
if ( inputStream != null ) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream,UTF8);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader, BUFFER_SIZE);
String receiveString = "";
StringBuilder stringBuilder = new StringBuilder();
while ( (receiveString = bufferedReader.readLine()) != null ) {
stringBuilder.append(receiveString);
}
inputStream.close();
ret = stringBuilder.toString();
System.out.println(ret);
}
I was thinking about that it can be problem of encoding. there fore i added utf8 option.
However, it still doesn't work ..
Does anyone know solution of broken text ?
UPDATE:
I think, I solved problem.
I create new text file from window text editor and then i copy and paste content.
Now , it is reading file correctly

It may be wrong encoding for the given file, may be the file does not contain text, may be console does not support the characters.
Besides the code is too long, here's a one line solution
String s = new String(Files.readAllBytes(Paths.get(file)), "UTF-8");

The file may contain images or unsupported format, in that case it'll display like that.