count character in text file as input file

[aNNuur]

Hello,

I am a newbie... can anyone help me to figure out this code?

I want to count a character in the input text file and if they are more than 30 character..they will return a error message.

but my problem is.. it fuction only for the first line of the text file and pop the message. the go to the next line and pop the message.

how to make it function : read all the line in the input text file, if more than 30 char in that text file they will pop a message?

import java.io.*;
import javax.swing.JOptionPane;


public class Main {


static public String getContents(File aFile)throws FileNotFoundException, IOException {


if (aFile == null ) {
throw new IllegalArgumentException("File should not be null.");
}
if (!aFile.exists()) {
throw new FileNotFoundException ("File does not exist: " + aFile);
}

StringBuffer contents = new StringBuffer();


BufferedReader input = null;

try {

input = new BufferedReader( new FileReader(aFile) );
String line = null;
(( line = input.readLine()) != null){

long numChar = 0;
numChar += line.length();

JOptionPane.showMessageDialog(null,numChar,"Charac ter in the Message",JOptionPane.INFORMATION_MESSAGE);


contents.append(line);

}
}
catch (FileNotFoundException ex) {
ex.printStackTrace();
}
catch (IOException ex){
ex.printStackTrace();
}
finally {
try {
if (input!= null) {

input.close();
}
}
catch (IOException ex) {
ex.printStackTrace();
}
}
return contents.toString();
}


public static void main (String[] args) throws IOException {

File testFile = new File("key1.txt");

JOptionPane.showMessageDialog(null, getContents(testFile),"Original File",JOptionPane.INFORMATION_MESSAGE);

}
}


hmmm? or there is other suggestion?

[dgaur]

Dude.. I m totally lost in this code..

Could you pls tell me where are you checking the characters count with 30??

Any while reading the lines from file I don't see any while loop in the code, is it typo mistake??

[fceruti]

you can get all the file in a string and then apply .lenght();

[j2me64]

but my problem is.. it fuction only for the first line of the text file and pop the message. the go to the next line and pop the message.

clear, your code is saying if ((line = input.readLine()) != null) then after the first line no more lines can be computed. so use a while instead. you made a little confusion in your code between the basics sequence, decision and iteration. here is a small modification that runs. i commended out some statements because i couldn't guess the purpose. perhaps you must adapt it again.

import java.io.*;
import javax.swing.JOptionPane;

public class Main {

	static public long getContents(File aFile) throws FileNotFoundException,
			IOException {

		if (aFile == null) {
			throw new IllegalArgumentException("File should not be null.");
		}
		if (!aFile.exists()) {
			throw new FileNotFoundException("File does not exist: " + aFile);
		}

		StringBuffer contents = new StringBuffer();

		BufferedReader input = null;
		
		long numChar = 0;

		try {

			input = new BufferedReader(new FileReader(aFile));
			String line = null;
			while ((line = input.readLine()) != null) {
				numChar += line.length();

//				JOptionPane.showMessageDialog(null, numChar,
//						"Charac ter in the Message",
//						JOptionPane.INFORMATION_MESSAGE);
//
//				contents.append(line);

			}
		} catch (FileNotFoundException ex) {
			ex.printStackTrace();
		} catch (IOException ex) {
			ex.printStackTrace();
		} finally {
			try {
				if (input != null) {

					input.close();
				}
			} catch (IOException ex) {
				ex.printStackTrace();
			}
		}
		return numChar;
	}

	public static void main(String[] args) throws IOException {

		File testFile = new File(
				"D:/temp/testfile.txt");

		if (getContents(testFile) <= 30) {
		JOptionPane.showMessageDialog(null, getContents(testFile),
				"Original File", JOptionPane.INFORMATION_MESSAGE);
		} else {
			JOptionPane.showMessageDialog(null, "Too much characters!",
					"Original File", JOptionPane.ERROR_MESSAGE);
		}

	}
}

[JosAH]

You don't have to open and read any file contents; have a look at the File.length() method.

kind regards,

Jos

[j2me64]

You don't have to open and read any file contents; have a look at the File.length() method.

good point. i noticed, that the number of chars the File.length gives back is higher then the one of numChar += line.length(); are cr and file end also counted?

[RamyaSivakanth]

I don't think length() method will help to find gthe number of characters.

[JosAH]

good point. i noticed, that the number of chars the File.length gives back is higher then the one of numChar += line.length(); are cr and file end also counted?

Yep, it includes \r and \n characters too; if you don't want that you have to actually read the entire file and ignore those characters (possibly implicitly by reading entire lines).

kind regards,

Jos