CODEWITHSUNDEEP
java
High-Cyber
High-Cyber

Reputation: 33

How to read records from a text file?

I tried this:
public static void ReadRecord()
    {
        String line = null;
        try
        {
        FileReader fr = new FileReader("input.txt");
        BufferedReader br = new BufferedReader(fr);

        line = br.readLine();
         while(line != null)
         {
                System.out.println(line);
         }  

        br.close();
        fr.close();
        }
        catch (Exception e)
        {
        }
    }
}

It non stop and repeatedly reads only one record that i had inputtd and wrote into the file earlier...How do i read records and use tokenization in reading records?

Upvotes: 0

Views: 4133

Answers (4)

DoesEatOats
DoesEatOats

Reputation: 671

For a text file called access.txt locate for example on your X drive, this should work.

public static void readRecordFromTextFile throws FileNotFoundException

{
    try {
        File file = new File("X:\\access.txt");
        Scanner sc = new Scanner(file);
        sc.useDelimiter(",|\r\n");
        System.out.println(sc.next());
        while (sc.hasNext()) {
            System.out.println(sc.next());
        }

        sc.close();// closing the scanner stream
    } catch (FileNotFoundException e) {

        System.out.println("Enter existing file name");

        e.printStackTrace();
    }

}

Upvotes: 0

Johny
Johny

Reputation: 2188

You have to read the lines in the file repeatedly in the loop using br.readLine(). br.readLine() reads only one line at time.

do something like this:

while((line = br.readLine()) != null) {
    
     System.out.println(line);
}

Check this link also if you have some problems. http://www.mkyong.com/java/how-to-read-file-from-java-bufferedreader-example/

Tokenization

If you want to split your string into tokens you can use the StringTokenizer class or can use the String.split() method.

StringTokenizer Class

StringTokenizer st = new StringTokenizer(line);
while (st.hasMoreTokens()) {
     System.out.println(st.nextToken());
}

st.hasMoreTokens() - will check whether any more tokens are present.
st.nextToken() - will get the next token

String.split()

String[] result = line.split("\\s"); // split line into tokens
for (int x=0; x<result.length; x++) {
     System.out.println(result[x]);
}

line.split("\\s") - will split line with space as the delimiter. It returns a String array.

Upvotes: 3

Benjamin
Benjamin

Reputation: 2286

Try This :

     BufferedReader br = new BufferedReader(new FileReader("input.txt"));
     while((line=br.readline())!=null)
     System.out.println(line);

Upvotes: 0

xrcwrn
xrcwrn

Reputation: 5327

try this

     while((line = br.readLine()) != null)
     {
            System.out.println(line);
     }

Upvotes: 1

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