Java splitting a string with newlines into an array, where the string is read from a file using buffered reader

Question

I'm loading a file into a buffer which is loaded into a string buffer. I'm then copying this string buffer into a string. The string prints out as...

Sam

ravon

Ashley

annie

So I want to make an array for this string so I can put the first line and second line at a time into a function that creates a node for a LinkedList that takes a username and password ... ex Username: Sam , Password: ravon. This is then loaded into a LinkedList. All of my functionally is working when it comes to the LinkedList, but I can't seem to split my string into an array.

I thought something like...

String[] userContent = content.split("\n") would place each element of content into userContent[n] string where

userContent[0] = Sam, userContent[1] = ravon and etc. However, this is not the case.

code I'm using - It takes a linked list and file name as arguments

    public static void readUserFile(String fName, LinkedList<dataUser> ll) {
    try {
        File file = new File(fName);
        FileReader fileReader = new FileReader(file);
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        StringBuffer stringBuffer = new StringBuffer();
        String line;

        while ((line = bufferedReader.readLine()) != null) {
            stringBuffer.append(line);
            stringBuffer.append("\n");
        }

        LineNumberReader  lnr = new LineNumberReader(new FileReader(new File("userData.txt")));
        lnr.skip(Long.MAX_VALUE);
        lnr.close();
        fileReader.close();
        int realSize = lnr.getLineNumber();
        //String[] userContent = line.split("\n");
        String content = stringBuffer.toString();
        String[] userContent = content.split("/n");

         //this prints nothing, would expect it to print exactly what content prints
        for(int i = 0; i < realSize; i++) {
            System.out.println(userContent[i]);
        }

        /*  this is what I want to load the userContent string into
        //not working
        for(int i = 0; i < realSize; i++) {
            dataUser tempUser = new dataUser(userContent[i],            userContent[i+1]);
            ll.add(tempUser);
            i = i + 1;
        }*/

        //System.out.println(content);  //works and prints the file with new lines
        //System.out.println("Contents of file:");
        //System.out.println(stringBuffer.toString());
    } catch (IOException e) {
        e.printStackTrace();
    }
}

java.nio.file.Files.readAllLines is probably the way to go. — MadConan
– MadConan, Commented May 20, 2015 at 20:27
Why don't you just fill an ArrayList of strings while you are reading instead of appending to a StringBuffer? — RealSkeptic
– RealSkeptic, Commented May 20, 2015 at 20:29
Oh, and your problem is that you are splitting by /n instead of \n. — RealSkeptic
– RealSkeptic, Commented May 20, 2015 at 20:31
readAllLines will place it into one giant string? I haven't used Java before so I've only played with the LinkedList library so far in java. — user3622460
– user3622460, Commented May 20, 2015 at 20:31
Ah that was it RealSkeptic, thanks for noticing the error. I also forgot to add +1 to realSize to account for 0 in the array size. — user3622460
– user3622460, Commented May 20, 2015 at 20:33

JimW · Accepted Answer · 2015-05-20 20:52:51Z

1

For what it's worth the following will do the same thing your code is doing without creating/splitting a String and reopening a file unnecessarily and also won't thrown an exception if you happen to run into a file with a user but no password.

BufferedReader br = new BufferedReader(new FileReader(fName));
String user;

while ((user = br.readLine()) != null) {
    String pass = br.readLine();
    if (pass == null) {
        System.out.println("Warning: User found with no password: " + user);
        break;
    }
    ll.add(new DataUser(user, pass));
}

answered May 20, 2015 at 20:52

JimW

1868 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

MRK187 Over a year ago

How does this answer the OPs question?

JimW Over a year ago

The OP has additional issues, for example the hard coding of "userData.txt" instead of using fName and using i+1 while iterating over an array. All that code is completely unnecessary.

MRK187 · Accepted Answer · 2015-05-20 20:32:33Z

0

now you are only checking for whitespaces,

split("\n")

use %%n for new lines, or you can use %%W which is not alphanumeric characters happy coding

answered May 20, 2015 at 20:32

MRK187

1,6152 gold badges14 silver badges21 bronze badges

Collectives™ on Stack Overflow

Java splitting a string with newlines into an array, where the string is read from a file using buffered reader

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related