Store text file content line by line into array

Question

all,I\'m now facing the problem of no idea on storing the content in text file into the array. The situation is like, text file content:

abc1
xyz2
rxy3


        

Answer 1

When you do str = in.readLine()) != null you read one line into str variable and if it's not null execute the while block. You do not need to read the line one more time in arr[i] = in.readLine();. Also use lists instead of arrays when you do not know the exact size of the input file (number of lines).

BufferedReader in = new BufferedReader(new FileReader("path/of/text"));
String str;

List<String> output = new LinkedList<String>();

while((str = in.readLine()) != null){
    output.add(str);
}

String[] arr = output.toArray(new String[output.size()]);

Answer 2

You can use this full code for your problem. For more details you can check it on appucoder.com

class FileDemoTwo{
    public static void main(String args[])throws Exception{
        FileDemoTwo ob = new FileDemoTwo();
        BufferedReader in = new BufferedReader(new FileReader("read.txt"));
        String str;
        List<String> list = new ArrayList<String>();
        while((str =in.readLine()) != null ){
            list.add(str);
        }
        String[] stringArr = list.toArray(new String[0]);
        System.out.println(" "+Arrays.toString(stringArr)); 
    }

}

Answer 3

Try this:

String[] arr = new String[3];// if size is fixed otherwise use ArrayList.
int i=0;
while((str = in.readLine()) != null)          
    arr[i++] = str;

System.out.println(Arrays.toString(arr));

Answer 4

Suggest use Apache IOUtils.readLines for this. See link below.

http://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/IOUtils.html

Answer 5

You can use this code. This works very fast!

public String[] loadFileToArray(String fileName) throws IOException {
    String s = new String(Files.readAllBytes(Paths.get(fileName)));
    return Arrays.stream(s.split("\n")).toArray(String[]::new);
}