How do I convert the contents of a text file to a single variable? (java)

Question

(The file includes a paragraph)

A rainy day is the bearer of good weather with refrigerating breeze and rain showers. It refreshes everyone by making the climate cool and delightsome and brings in a sigh of relief from the scorching heat. Rainy day gives us relief from the usually hot and humid climate.

Can I just save the entire paragraph to a single String variable (say its called "fullStory")?

File story = new File("story.txt");
//Help read words in file
FileInputStream fileStr1 = new FileInputStream(story);
//Reads one character
InputStreamReader input_1 = new InputStreamReader(fileStr1);
//BufferedReader reads from the input stream
BufferedReader wordReader1 = new BufferedReader(input_1);

I just answered your question in full. What elaboration are you after? Maybe **you** should elaborate on your question? What have you do so far and what problems are you facing? — Scary Wombat, Jun 09 '21 at 01:35
Basically I have a paragraph saved in a text file. I want to save it as a string variable so i can alter it by traversing through each character and then print the altered version. I'm trying to find the code online I need to convert all the contents of the text file to a single string. @ScaryWombat — Chaos, Jun 09 '21 at 01:38
Well show us your code so that we can see what is wrong with it. — Scary Wombat, Jun 09 '21 at 01:40

JayC667 · Answer 1 · 2021-06-12T09:35:04.140

This here reads all bytes of a file:

static public byte[] readBytes(final File pFile) throws FileNotFoundException, IOException {
    final long size = pFile.length();
    if (size > Integer.MAX_VALUE) throw new RuntimeException("File size is too big to be read into array!");

    final byte[] ret = new byte[(int) size];
    try (FileInputStream fis = new FileInputStream(pFile)) {
        fis.read(ret);
    }

    return ret;
}

So once you get the bytes, you can convert it into a String:

byte[] data = readBytes(file);
String text = new String(text, StandardCharsets.UTF_8);

What I need to mention: this can only read files up to 2 GBytes, because 2^31-1 is the max amount of bytes an int can address and thus a Java array can hold data.

But having one text file with such a size is highly unlikely and by design a problem, so this here is the fastest and easiest way.

Since Java 1.7 there's also Files.readAllBytes(path), but that hits the same restrictions.

Thank you very much but would something simpler like this work? String content = new String(Files.readAllBytes(Paths.get("story.txt"))); @JayC667 — Chaos, Jun 09 '21 at 02:01
Depends on your Java version. 1.7+, your method works. Just be aware of the Encoding when you create the String, as in my example I explicitly use `StandardCharsets.UTF_8` to make it clear the file might have another encoding. — JayC667, Jun 09 '21 at 09:35

How do I convert the contents of a text file to a single variable? (java)

1 Answers1