The removeIf() method of java.util.concurrent.LinkedTransferQueue is an in-built function is Java which is used to remove all of the elements of this queue that satisfies a given predicate filter which is passed as a parameter to the method.
Syntax:
public boolean removeIf(Predicate filter)
Parameters: This method takes a parameter filter which represents a predicate which defines the filtering criteria for elements to be removed.
Return Value: This method returns a boolean value depicting if some the specified element has been removed. It returns True if the predicate returns true and the elements have been removed.
Exceptions: This method throws NullPointerException if the specified filter is null.
Below program illustrates the removeIf() function of LinkedTransferQueue class :
Program 1:
// Java code to illustrate // removeIf() method of LinkedTransferQueue import java.util.concurrent.LinkedTransferQueue;
import java.util.*;
public class GFG {
public static void main(String[] args)
throws InterruptedException
{
// create object of LinkedTransferQueue
LinkedTransferQueue<Integer> LTQ
= new LinkedTransferQueue<Integer>();
// Add numbers to end of LinkedTransferQueue
// using add() method
LTQ.add( 6 );
LTQ.add( 3 );
LTQ.add( 5 );
LTQ.add( 15 );
LTQ.add( 20 );
// Print the LTQ
System.out.println( "Linked Transfer Queue initially: "
+ LTQ);
// Remove all multiple of 3
// using removeIf() method
if (LTQ.removeIf(n -> (n % 3 == 0 )))
System.out.println( "Multiples of 3 removed." );
else
System.out.println( "No element removed." );
// Print the LTQ
System.out.println( "Current Linked Transfer Queue: "
+ LTQ);
}
} |
Linked Transfer Queue initially: [6, 3, 5, 15, 20] Multiples of 3 removed. Current Linked Transfer Queue: [5, 20]
Program 2: To demonstrate NullPointerException
// Java code to illustrate // removeIf() method of LinkedTransferQueue import java.util.concurrent.LinkedTransferQueue;
import java.util.*;
public class GFG {
public static void main(String[] args)
throws InterruptedException
{
// create object of LinkedTransferQueue
LinkedTransferQueue<Integer> LTQ
= new LinkedTransferQueue<Integer>();
// Add numbers to end of LinkedTransferQueue
// using add() method
LTQ.add( 6 );
LTQ.add( 3 );
LTQ.add( 5 );
LTQ.add( 15 );
LTQ.add( 20 );
// Print the LTQ
System.out.println( "Linked Transfer Queue initially: "
+ LTQ);
try {
// Remove all multiple of 3
// using removeIf() method
System.out.println( "Trying to remove null." );
LTQ.removeIf( null );
}
catch (Exception e) {
System.out.println(e);
}
}
} |
Linked Transfer Queue initially: [6, 3, 5, 15, 20] Trying to remove null. java.lang.NullPointerException