java: how to read a txt file to an Array of strings

Question

Hi i want to read a txt file with N lines and the result put it in an Array of strings.

Here's some alternatives ( they just need a little tweak ) http://stackoverflow.com/questions/326390/how-to-create-a-java-string-from-the-contents-of-a-file — OscarRyz, Jun 04 '10 at 19:23
And another: http://www.exampledepot.com/egs/java.io/ReadLinesFromFile.html — OscarRyz, Jun 04 '10 at 19:26

score 30 · Accepted Answer · answered Jun 04 '10 at 19:22

30

Use a java.util.Scanner and java.util.List.

Scanner sc = new Scanner(new File(filename));
List<String> lines = new ArrayList<String>();
while (sc.hasNextLine()) {
  lines.add(sc.nextLine());
}

String[] arr = lines.toArray(new String[0]);

answered Jun 04 '10 at 19:22

polygenelubricants

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this is the answer, thanks men :) – Enrique San Martín Jun 04 '10 at 19:44
3

@Enrique: read the API about how `Scanner` handles `IOException`. – polygenelubricants Jun 04 '10 at 19:49
How to print all elements of String[] arr? – Chinmoy Jun 13 '16 at 06:37
you can use a for over an array, in eclipse you can use the autocomplete fuction for an example like: https://ideone.com/ZMTesT – Enrique San Martín May 20 '18 at 05:39

score 6 · Answer 2 · answered Jun 04 '10 at 19:21

6

FileUtils.readLines(new File("/path/filename"));

From apache commons-io

This will get you a List of String. You can use List.toArray() to convert, but I'd suggest staying with List.

answered Jun 04 '10 at 19:21

Bozho

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looks like this method is deprecated now. – Praveen Kumar Jul 02 '19 at 17:45

score 2 · Answer 3 · answered Jun 04 '10 at 19:21

2

Have you read the Java tutorial?

For example:

Path file = ...;
InputStream in = null;
try {
    in = file.newInputStream();
    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
    String line = null;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException x) {
    System.err.println(x);
} finally {
    if (in != null) in.close();
}

answered Jun 04 '10 at 19:21

JRL

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yeah, i read the java tutorial and others books, this don't resolve the problem because i want to put all the lines of the file in an Array of strings like: String [] content = new String[lenght_of_the_string]; int i = 0; while ((line = reader.readLine()) != null { content[i] = line; i++; } – Enrique San Martín Jun 04 '10 at 19:48

score -1 · Answer 4 · answered Jun 04 '10 at 19:22

-1

Set up a BufferedReader to read from the file, then pick up lines from from the buffer however many times.

answered Jun 04 '10 at 19:22

crazyscot

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java: how to read a txt file to an Array of strings

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