Read and Write in Java

My question is this:

How can you write to a .txt file (or excel, doesn't really matter) in java and read from it to compare it to other variables.

Any Ideas or examples?


Thanks !@

Welcome to the forums
Hope this code helps

Code:

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import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;


public class FileReader
{
    /**
    * @param args the command line arguments
    */
    public static void main(String[] args)
    {
        DataInputStream reader = null;
        if ( args.length < 1 )
        {
            System.out.println("Usage: FileReader path");
            return;
        }
        System.out.print(readTextFile(args[0]));
    }

    /**
    * Read from a file into a string
    * @param filePath
    * @return
    */
    private static String readTextFile(String filePath)
    {
        BufferedReader reader = null;
        try
        {
            reader = new BufferedReader(new java.io.FileReader(filePath));
            StringBuilder builder = new StringBuilder();
            while (reader.ready())
            {
                builder.append(reader.readLine() + "\n");
            }
            return builder.toString();
        }
        catch (FileNotFoundException ex)
        {
            Logger.getLogger(FileReader.class.getName()).log(Level.SEVERE, null, ex);
        }
        catch (IOException ex)
        {
            Logger.getLogger(FileReader.class.getName()).log(Level.SEVERE, null, ex);
        }
        finally
        {
            try
            {
                reader.close();
            }
            catch (IOException ex)
            {
                Logger.getLogger(FileReader.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        return null;
    }
}

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