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> Reading From A Text File
kvarnerexpress
post Dec 27 2004, 12:16 AM
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Reading from a text file
whats up guys, got some more questions. we are starting to learn how to write and read strings to/from txt files. wel thats pretty easy, but how would i retrieve only the first 2 lines of the txt file, for example, if i wanted the first 2 lines, not any other, how would i do it:
12 <--i only need this one and
90 <--this one
12
6
-9

how would i go baout doin this.
thnks

ke

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karlo
post Dec 27 2004, 06:55 AM
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Use PHP! It's a lot more easy and fast! tongue.gif

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cse-icons
post Dec 28 2004, 05:54 AM
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I suppose the following is what u need...

CODE

File inputFile = new File("C:\\test.java"); // put ur filename here
   
   BufferedReader br = new BufferedReader(new FileReader(inputFile));
   
   System.out.println(br.readLine());
  System.out.println(br.readLine());


you can read any no.. of lines using the br reader.
There are otherways too in which you can read files in java...
I suppose u wanted java coz... this is a Java forum...
there are other methods like readLine, readInt, readLong etc.. which you can explore as per your requirements. Go thru the api of the java.io package classes.
Hope this is helpful...

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spirit_valley
post Dec 28 2004, 06:11 AM
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QUOTE(kvarnerexpress @ Dec 27 2004, 08:16 AM)
we are starting to learn how to write and read strings to/from txt files.
*


Excuse me... but what language do you mean exactly?

QUOTE(karlo @ Dec 27 2004, 02:55 PM)
Use PHP! It's a lot more easy and fast! tongue.gif
*


People have their own reasons why they don't use PHP.

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Xedos
post Dec 29 2004, 05:52 AM
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If not php, use perl. Its all good. The main goal in any language is to let you do the most things in the least set of lines. I say PHP. PHP is the best language for anything and alot simpler. I also see PHP as more wildy documented and theres alot more support. Go the Smart Way, Use PHP.

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csmith
post Sep 25 2005, 07:20 AM
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The above code in the previous message would work:

QUOTE
File inputFile = new File("C:\\test.java"); // put ur filename here
   
    BufferedReader br = new BufferedReader(new FileReader(inputFile));
   
    System.out.println(br.readLine());
  System.out.println(br.readLine());


However, if you wish to read only a certain number of lines, you could also add the following code:

CODE
try {

       File inputFile = new File("C:\\test.java"); // put ur filename here
       BufferedReader in = new BufferedReader(new FileReader("infilename"));
       String str;
       int counter = 0;
       while (((str = in.readLine()) != null) && i < 2) {

//set i < the number of lines which you wish to read - i.e., if you wish to read the //first 10 lines only, you would set i < 10

           System.out.println(str);
           i++;  
       }
       in.close();
   } catch (IOException e) {
   }


Notice from cmatcmextra:
Use quote tags when copying and code tags when using code!!


This post has been edited by cmatcmextra: Sep 25 2005, 07:38 AM

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Dragonfly
post Sep 25 2005, 08:15 AM
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Yes, using programming language for a site is always better if the site has to be dynamic.. otherwise plain html pages are the best. they are so friendly with search engines.

I don't quite understand text files the thread starter is talking about.

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beeseven
post Sep 26 2005, 09:29 PM
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Ever think that not all programming languages are online?... I know it's hard to imagine, but it's true ohmy.gif

BufferedReaders are good, but if you're using Java 1.5.0 then you can use Scanners which are a bit easier. Here's code to read from a file with a scanner (you also have to import java.util.Scanner and java.io.File):
CODE
public static void main(String[] args) throws FileNotFoundException //because you're using the File class
{
    Scanner infile = new Scanner(new File("filename.txt"));
    String s1 = infile.next(); //you could use int n = infile.nextInt() if you want an int
    String s2 = infile.next();
    infile.close();
    ...
}

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dul
post Oct 19 2005, 01:00 AM
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QUOTE(kvarnerexpress @ Dec 27 2004, 12:16 AM)
try {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String str = "";
        while (str != null) {
            System.out.print("> prompt ");
            str = in.readLine();
            process(str);
        }
    } catch (IOException e) {
    }



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