Console readPassword() method in Java with Examples

Last Updated : 27 Sep, 2022

The readPassword() method of Console class in Java is of two types:

1. The readPassword() method of Console class in Java is used to read a password or passphrase from the console with disabled echoing.

Syntax:

public char[] readPassword()

Parameters: This method does not accept any parameter.

Return value: This method returns a character array that contains the password or passphrase read from the console. It returns null if the stream is ended.

Exceptions: This method throws IOError if an I/O error occurs.

Note: System.console() returns null in an online IDE.

Below programs illustrate readPassword() method in Console class in IO package:

Program 1:

// Java program to illustrate 
// Console readPassword() method 
  
import java.io.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
        // Create the console object 
        Console cnsl 
            = System.console(); 
  
        if (cnsl == null) { 
            System.out.println( 
                "No console available"); 
            return; 
        } 
  
        // Read line 
        String str = cnsl.readLine( 
            "Enter username : "); 
  
        // Print username 
        System.out.println( 
            "Username : " + str); 
  
        // Read password 
        // into character array 
        char[] ch = cnsl.readPassword( 
            "Enter password : "); 
  
        // Print password 
        System.out.println( 
            "Password : " + ch); 
    } 
} 

Output:

Program 2:

// Java program to illustrate 
// Console readPassword() method 
  
import java.io.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
        // Create the console object 
        Console cnsl 
            = System.console(); 
  
        if (cnsl == null) { 
            System.out.println( 
                "No console available"); 
            return; 
        } 
  
        // Read line 
        String str = cnsl.readLine( 
            "Enter username : "); 
  
        // Print username 
        System.out.println( 
            "Username : " + str); 
  
        // Read password 
        // into character array 
        char[] ch = cnsl.readPassword( 
            "Enter password : "); 
  
        // Print password 
        System.out.println( 
            "Password : " + ch); 
    } 
} 

Output:

2. The readPassword(String, Object) method of Console class in Java is used to read a password or passphrase from the console by providing a formatted prompt. It returns the password in the character array.

Syntax:

public char[] readPassword(String fmt,
                      Object... args)

Parameters: This method accepts two parameters:

fmt – It represents the format of the string.
args – It represents the arguments that are referenced by the format specifiers in the string format.

Return value: This method returns the character array that contains the password or passphrase read from the console.It returns null if the stream is ended.

Exceptions:

IllegalFormatException – This method throws IllegalFormatException if string format contains an illegal syntax or a format specifier is not compatible with the given arguments or insufficient arguments given the format string or other conditions that are illegal.
IOError – This method throws IOError if an I/O error occurs.

Below programs illustrate readPassword(String, Object) method in Console class in IO package:

Program 1:

// Java program to illustrate 
// Console readPassword(String, Object) method 
  
import java.io.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
        // Create the console object 
        Console cnsl 
            = System.console(); 
  
        if (cnsl == null) { 
            System.out.println( 
                "No console available"); 
            return; 
        } 
  
        String fmt = "%2$5s %3$10s%n"; 
  
        // Read line 
        String un = cnsl.readLine( 
            fmt, "Enter", "Username : "); 
  
        // Print username 
        System.out.println( 
            "Username : " + un); 
  
        // Read password 
        // into character array 
        char[] pwd = cnsl.readPassword( 
            fmt, "Enter", "Password : "); 
  
        // Print password 
        System.out.println( 
            "Password : " + pwd); 
    } 
} 

Output:

Program 2:

// Java program to illustrate 
// Console readPassword(String, Object) method 
  
import java.io.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
        // Create the console object 
        Console cnsl 
            = System.console(); 
  
        if (cnsl == null) { 
            System.out.println( 
                "No console available"); 
            return; 
        } 
  
        String fmt = "%2$5s %3$10s%n"; 
  
        // Read line 
        String un = cnsl.readLine( 
            fmt, "Enter", "Username : "); 
  
        // Print username 
        System.out.println( 
            "Username : " + un); 
  
        // Read password 
        // into character array 
        char[] pwd = cnsl.readPassword( 
            fmt, "Enter", "Password : "); 
  
        // Print password 
        System.out.println( 
            "Password : " + pwd); 
    } 
} 