CODEWITHSUNDEEP
javaandroidinputstream
sonicboom
sonicboom

Reputation: 5028

What is most appropriate way to read all data from a text file in one go?

I have a text file and I want to read the entire contents of it into a String variable. The file is being opened as an InputStream as I am using Android's assetManager.open() method.

What is the best practise way to read the entire contents into a String? I am currently wrapping the InputStream with an InputStreamReader and then a BufferedReader and using a while loop I read in the text line by line with the readLine() method.

Is there a better way of reading in this text considering I there is no requirement to read it in line by line, I'd like to get it all in one go if possible

Upvotes: 5

Views: 2958

Answers (5)

Joop Eggen
Joop Eggen

Reputation: 109603

One normally should not reinvent the wheel, so use the apache commons library, if the overhead is bearable on Android. Use org.apache.commons.io.IOUtils.toString.

InputStream in = new FileInputStream(new File("a.txt"));
String s = IOUtils.toString(in, "UTF-8");

Upvotes: 2

mindas
mindas

Reputation: 26733

Scanner scanner = new Scanner(file, encoding);      
scanner.useDelimiter("\\A");
if (!scanner.hasNext()) {       // corner case -- file is empty
    return "";
}
String result = scanner.next();
scanner.close();

Upvotes: 0

TechSpellBound
TechSpellBound

Reputation: 2555

This is another possible way of doing it.

BufferedReader br = new BufferedReader(new FileReader("a.txt"));
char[] cbuf = new char[500];
br.read(cbuf);
String fileContents = new String(cbuf);

Upvotes: 0

Dinesh Vadivelu
Dinesh Vadivelu

Reputation: 29

You can also use Scanner class

Scanner scan = new Scanner(file);  
String content = scan.next();

Upvotes: -1

assylias
assylias

Reputation: 328785

This is what Java 7 Files.readAllLines method does - I would expect it to be a very good way of doing it (it uses a try-with-resources syntax which is easily transposable to work on android):

public static List<String> readAllLines(Path path, Charset cs) throws IOException {
    try (BufferedReader reader = newBufferedReader(path, cs)) {
        List<String> result = new ArrayList<String>();
        for (;;) {
            String line = reader.readLine();
            if (line == null)
                break;
            result.add(line);
        }
        return result;
    }
}

In your case, you could append the strings to a StringBuilder instead of adding them to a list.

Upvotes: 5

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