Input and Output - Java - page 365

cons.readPassword("Password:") . This method returns an array of bytes, which can be
used directly in some encryption and security APIs, or can easily be converted into a String .
It is generally advised to overwrite the byte array after use to prevent security leaks when
other code can access the stack, although the benefits of this are probably reduced when
you've constructed a String as we do in the simple example shown in Example 10-1 .

Example 10-1. src/main/java/io/ReadPassword.java
public public class class ReadPassword ReadPassword {

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

Console cons ;
iif (( cons = System . console ()) != null

static void

null ) {

char char [] passwd = null null ;

try try {

passwd = cons . readPassword ( "Password:" );
// In real life you would send the password into authentication code
System . out . println ( "Your password was: " + new new String ( passwd ));

} finally finally {

// Shred this in-memory copy for security reasons
iif ( passwd != null

null ) {
java . util . Arrays . fill ( passwd , ' ' );

}

}
} else else {

throw

throw new new RuntimeException ( "No console, can't get password" );

}

}

}

Writing Standard Output or Standard Error

Problem

You want your program to write to the standard output or the standard error stream.

Solution

Use System.out or System.err as appropriate.