Question

I have a text file where i have names and passwords separated by :.

user1:pwd1
user2:pwd2

In the login page if the user gives the correct username and password it will lead you to the welcome page. But I am not getting this properly. The output which i get is

user1
pwd1
inside try
user1
pwd1
true
welcome user1
user2
pwd2
false
not equal

My code is below.

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.util.regex.*; 
import com.sun.org.apache.xalan.internal.xsltc.compiler.Pattern;


public class TextFile {

    /**
     * @param args
     */

    public void getNamePwd(String name, String pwd) {
        // TODO Auto-generated method stub
        System.out.println(name);
        System.out.println(pwd);
        String[] splitVals=null;
        try{
            System.out.println("inside try");
            String strLine;
            BufferedReader br = new BufferedReader(new FileReader("D:\\test\\text.txt"));
            while((strLine=br.readLine())!=null){
            splitVals=strLine.split(":");
            for(int i=0;i<splitVals.length;i=i+2){
            System.out.println(splitVals[i].toString());
            System.out.println(splitVals[i].toString());
            String nameUser=splitVals[i].toString();
            String passWord=splitVals[i+1].toString();
            System.out.println(name.equals(nameUser));
            if((name.equals(nameUser))&&(pwd.equals(passWord))){
                System.out.println("welcome"+name);
                }
            else{
                System.out.println("not equal");
            }
            }
            }
        }catch(Exception e){

        }
    }

}

please help me..

Answer 1

I suspect that you want to stop looking for username/password matches after you’ve found one… To do this you have to break the loop upon a match. To do this you do the following:

readLoop:
while((strLine=br.readLine())!=null){

    // ...
    String[] splitVals = strLine.split(":");

    if((name.equals(nameUser))&&(pwd.equals(passWord))){
        System.out.println("welcome"+name);
        break readLoop;
    }

    // ...
}

---

Besides, I don’t know why you need this loop:

for(int i=0;i<splitVals.length;i=i+2)

Recall that you read the file line by line. That is, the splitted array will contain the username and password of the current line.

To print the username / password you could do something like this:

System.out.printf("Username: %s, Password: %s%n", splitVals[0], splitVals[1]);

---

I would probably solve it using a Scanner. Something like this:

import java.io.*;
import java.util.Scanner;


public class TextFile {

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

        if (userPassOk("hello", "world"))
            System.out.println("Welcome");
        else
            System.out.println("Get out!");
    }

    private static boolean userPassOk(String user, String pass)
            throws FileNotFoundException {

        Scanner s = new Scanner(new File("test.txt"));
        while (s.hasNextLine()) {
            String[] userPass = s.nextLine().split(":");
            if (userPass[0].equals(user) && userPass[1].equals(pass))
                return true;
        }
        return false;
    }
}