JavaConsole

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Java Console Class

The Java Console class is be used to get input from console. It provides methods to read texts and passwords.

If you read password using Console class, it will not be displayed to the user.

The java.io.Console class is attached with system console internally. The Console class is introduced since 1.5.

Let's see a simple example to read text from console.

  1. String text=System.console().readLine();    
  2. System.out.println("Text is: "+text);    

Java Console class declaration

Let's see the declaration for Java.io.Console class:

  1. public final class Console extends Object implements Flushable  

Java Console class methods

Method

Description

Reader reader()

It is used to retrieve the reader object associated with the console

String readLine()

It is used to read a single line of text from the console.

String readLine(String fmt, Object... args)

It provides a formatted prompt then reads the single line of text from the console.

char[] readPassword()

It is used to read password that is not being displayed on the console.

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

It provides a formatted prompt then reads the password that is not being displayed on the console.

Console format(String fmt, Object... args)

It is used to write a formatted string to the console output stream.

Console printf(String format, Object... args)

It is used to write a string to the console output stream.

PrintWriter writer()

It is used to retrieve the PrintWriter object associated with the console.

void flush()

It is used to flushes the console.

How to get the object of Console

System class provides a static method console () that returns the singleton instance of Console class.

  1. public static Console console(){}   

Let's see the code to get the instance of Console class.

  1. Console c=System.console();  

Java Console Example

  1. import java.io.Console;  
  2. class ReadStringTest{    
  3. public static void main(String args[]){    
  4. Console c=System.console();    
  5. System.out.println("Enter your name: ");    
  6. String n=c.readLine();    
  7. System.out.println("Welcome "+n);    
  8. }    
  9. }  

Output

Enter your name: Nakul Jain
Welcome Nakul Jain

Java Console Example to read password

  1. import java.io.Console;  
  2. class ReadPasswordTest{    
  3. public static void main(String args[]){    
  4. Console c=System.console();    
  5. System.out.println("Enter password: ");    
  6. char[] ch=c.readPassword();    
  7. String pass=String.valueOf(ch);//converting char array into string    
  8. System.out.println("Password is: "+pass);    
  9. }    
  10. }  

Output

Enter password: 
Password is: 123