File to Array - Java

Question

I have created the following to code to display a file contents to a text area - and it is successful:

BufferedReader in = null;
try {
    in = new BufferedReader(new FileReader("C:\\Users\\emily\\Documents\\Parts.txt"));
    String str;
    while ((str = in.readLine()) != null) {
        jTextArea1.append("\n"+str);
    }
} catch (IOException e) {
} finally {
    try { in.close(); } catch (Exception ex) { }
}

My problem is that I need each line in an array. The idea for my proof of concept is that I would be able to enter the command :

jTextArea1 = Arrays.toString(fileArray);

The output should then be: [Part1, Part2, Part3]

In spite of my scouring of the internet, I can't seem to accomplish this. Can anyone tell me how to load these values into an Array (fileArray) instead of writing them into the jTextArea?

Are you open to adding libraries such as OpenCSV or Commons IO? — opticyclic
– opticyclic, Commented Dec 1, 2015 at 20:14
This is the first time I've worked with Java - kinda got thrown into it when someone in Engineering quit, so I'm not sure what that means, but if it helps, I'm open to anything... — user3508197
– user3508197, Commented Dec 1, 2015 at 20:54

Joop Eggen · Accepted Answer · 2015-12-01 21:40:50Z

2

The newer classes Path and Files will do.

Path path = Paths.get("C:\\Users\\emily\\Documents\\Parts.txt");
try {
    List<String> lines = Files.readAllLines(path, Charset.defaultCharset());
    String[] array = lines.toArray(new String[lines.size()]);
    ...
} catch (IOException e) {
    //Logger.getLogger(getClass().getName()).log(Level.SEVERE,
    //                                           path.toString(), e);
    System.err.println("Could not read file: " + e.getMessage());
}

Best would be to use just the List.

Add the handling of a possible IOException, probably when the file could not be read.

edited Dec 1, 2015 at 21:40

answered Dec 1, 2015 at 20:16

Joop Eggen

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4 Comments

user3508197 Over a year ago

This seems like it would be easiest, but I get the following error when I try to complie: "Uncompilable source code - type java.awt.List does not take parameters"

Joop Eggen Over a year ago

You must import java.util.List - you got the java.awt.List. See List

user3508197 Over a year ago

Uncompilable source code - unreported exception java.io.IOException; must be caught or declared to be thrown ??? (Apologies - this is the first time I've worked with Java at my office..)

user3508197 Over a year ago

Figured it out! I was trying to display the string...not the array :) Works perfectly! Thank you!

brso05 · Accepted Answer · 2015-12-01 20:13:54Z

0

You can try this:

BufferedReader in = null;
try {
    in = new BufferedReader(new FileReader("C:\\Users\\emily\\Documents\\Parts.txt"));
    String str;
    ArrayList<String> temp = new ArrayList<String>();
    String[] output;
    while ((str = in.readLine()) != null) {
        temp.add(str);
    }
    output = temp.toArray(new String[temp.size()]);
} catch (IOException e) {
} finally {
    try { in.close(); } catch (Exception ex) { }
}

answered Dec 1, 2015 at 20:13

brso05

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2 Comments

user3508197 Over a year ago

So how would I show the array in the jTextArea? I tried: jTextArea2=Arrays.toString(output); but it doesn't work. IDE suggests creating the local variable "output"...

brso05 Over a year ago

@user3508197 output is probably not accessible in the scope you are trying to access it in...Make it a global variable.

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