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

// 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

// 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

// 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

// 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);  } }