Read a text file line by line into strings

Question

How do I read the contents of a text file line by line into String without using a BufferedReader?

For example, I have a text file that looks like this inside:

Purlplemonkeys
greenGorilla

I would want to create two strings, then use something like this

File file = new File(System.getProperty("user.dir") + "\Textfile.txt");
String str = new String(file.nextLine());
String str2 = new String(file.nextLine());

That way it assigns str the value of "Purlplemonkeys", and str2 the value of "greenGorilla".

Solution 1

You should use an ArrayList.

File file = new File(fileName);
Scanner input = new Scanner(file);
List<String> list = new ArrayList<String>();

while (input.hasNextLine()) {
    list.add(input.nextLine());
}

Then you can access to one specific element of your list from its index as next:

System.out.println(list.get(0));

which will give you the first line (ie: Purlplemonkeys)

Solution 2

You can read text file to list:

List<String> lst = Files.readAllLines(Paths.get("C:\\test.txt"));

and then access each line as you want

P.S. Files - java.nio.file.Files

Solution 3

If you use Java 7 or later

List<String> lines = Files.readAllLines(new File(fileName));

for(String line : lines){
   // Do whatever you want
   System.out.println(line);
}

Solution 4

Sinse JDK 7 is quite easy to read a file into lines:

List<String> lines = Files.readAllLines(new File("text.txt").toPath())

String p1 = lines.get(0);
String p2 = lines.get(1);

Solution 5

You can use apache.commons.io.LineIterator

LineIterator it = FileUtils.lineIterator(file, "UTF-8");
 try {
   while (it.hasNext()) {
     String line = it.nextLine();
     // do something with line
   }
 } finally {
   it.close();
 }

One can also validate line by overriding boolean isValidLine(String line) method. refer doc

View more solutions

Comments

[user1231232141214124]

I don't think thats what he was looking for. line will be overwritten every time so its kind of pointless to even declare it. Why not just println(input.nextLine()) ? String line = ... is kind of redundant.

[Jan]

You don't need to know it's an ArrayList. Coding List<String> arrayList = new ArrayList<String>(); is cleaner

[Cardinal System]

I'm using Eclipse. Next to arrayList.add(Input.nextLine()); there is an error that says Multiple markers at this line - Syntax error on token ")", ; expected - implements java.awt.event.ActionListener.actionPerformed - Syntax error on token "(", ; expected and next to File file = new File(fileName); there is an error that says fileName cannot be resolved to a variable This also causes errors in other parts of my class.

[Cardinal System]

Also, where do I put the path leading to the txt file?

[Kevin Mee]

You put the filepath where fileName is. Like this: File file = new File("ThisIsYourFilePath.txt");

[Cardinal System]

My personal favorite approach :)

[Saikat]

The method readAllLines(Path) in the type Files is not applicable for the arguments (File)