LinkedBlockingQueue iterator() method in Java
Last Updated :
13 Jul, 2021
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The iterator() method of LinkedBlockingQueue returns an iterator of the same elements, as this LinkedBlockingQueue, in a proper sequence. The elements returned from this method contains all the elements in order from first(head) to last(tail) of LinkedBlockingQueue. The returned iterator is weakly consistent.
Syntax:
public Iterator<E> iterator()
Return Value: The method returns the iterator having same elements as present in LinkedBlockingQueue in order from first(head) to last(tail).
Below programs illustrates iterator() method of LinkedBlockingQueue class:
Program 1: Creating an Iterator from LinkedBlockingQueue which contains names of different student of a class.
// Java Program Demonstrate iterator()
// method of LinkedBlockingQueue
import java.util.concurrent.LinkedBlockingQueue;
import java.util.Iterator;
public class GFG {
public static void main(String[] args)
{
// define capacity of LinkedBlockingQueue
int capacityOfQueue = 7;
// create object of LinkedBlockingQueue
LinkedBlockingQueue<String> linkedQueue
= new LinkedBlockingQueue<String>(capacityOfQueue);
// Add element to LinkedBlockingQueue
linkedQueue.add("John");
linkedQueue.add("Tom");
linkedQueue.add("Clark");
linkedQueue.add("Kat");
// create Iterator of linkedQueue using iterator() method
Iterator<String> listOfNames = linkedQueue.iterator();
// print result
System.out.println("list of names:");
while (listOfNames.hasNext())
System.out.println(listOfNames.next());
}
}
// Java Program Demonstrate iterator()// method of LinkedBlockingQueueimport java.util.concurrent.LinkedBlockingQueue;import java.util.Iterator;public class GFG { public static void main(String[] args) { // define capacity of LinkedBlockingQueue int capacityOfQueue = 7; // create object of LinkedBlockingQueue LinkedBlockingQueue<String> linkedQueue = new LinkedBlockingQueue<String>(capacityOfQueue); // Add element to LinkedBlockingQueue linkedQueue.add("John"); linkedQueue.add("Tom"); linkedQueue.add("Clark"); linkedQueue.add("Kat"); // create Iterator of linkedQueue using iterator() method Iterator<String> listOfNames = linkedQueue.iterator(); // print result System.out.println("list of names:"); while (listOfNames.hasNext()) System.out.println(listOfNames.next()); }}Output:
list of names: John Tom Clark Kat
Program 2: Creating an Iterator from LinkedBlockingQueue which contains list of Employees.
// Java Program Demonstrate iterator()
// method of LinkedBlockingQueue
import java.util.concurrent.LinkedBlockingQueue;
import java.util.Iterator;
public class GFG {
public void collectIterator()
{
// define capacity of LinkedBlockingQueue
int capacityOfQueue = 7;
// create object of LinkedBlockingQueue
LinkedBlockingQueue<Employee> linkedQueue
= new LinkedBlockingQueue<Employee>(capacityOfQueue);
// Add element to LinkedBlockingQueue
Employee emp1 = new Employee("Sachin", "Developer", "39000");
Employee emp2 = new Employee("Sanjeev", "Tester", "26000");
// Add Employee Objects to linkedQueue
linkedQueue.add(emp1);
linkedQueue.add(emp2);
// create Iterator of linkedQueue using iterator() method
Iterator<Employee> listOfEmployee = linkedQueue.iterator();
// print result from iterator
System.out.println("list of Employees:");
while (listOfEmployee.hasNext()) {
System.out.println("*************************");
Employee emp = listOfEmployee.next();
System.out.println("Employee Name : " + emp.name);
System.out.println("Employee Position : " + emp.position);
System.out.println("Employee Salary : " + emp.salary);
}
}
// create an Employee Object with name,
// position and salary as an attribute
public class Employee {
public String name;
public String position;
public String salary;
Employee(String name, String position, String salary)
{
this.name = name;
this.position = position;
this.salary = salary;
}
@Override
public String toString()
{
return "Employee [name=" + name + ", position="
+ position + ", salary=" + salary + "]";
}
}
// Main Method
public static void main(String[] args)
{
GFG gfg = new GFG();
gfg.collectIterator();
}
}
// Java Program Demonstrate iterator()// method of LinkedBlockingQueueimport java.util.concurrent.LinkedBlockingQueue;import java.util.Iterator;public class GFG { public void collectIterator() { // define capacity of LinkedBlockingQueue int capacityOfQueue = 7; // create object of LinkedBlockingQueue LinkedBlockingQueue<Employee> linkedQueue = new LinkedBlockingQueue<Employee>(capacityOfQueue); // Add element to LinkedBlockingQueue Employee emp1 = new Employee("Sachin", "Developer", "39000"); Employee emp2 = new Employee("Sanjeev", "Tester", "26000"); // Add Employee Objects to linkedQueue linkedQueue.add(emp1); linkedQueue.add(emp2); // create Iterator of linkedQueue using iterator() method Iterator<Employee> listOfEmployee = linkedQueue.iterator(); // print result from iterator System.out.println("list of Employees:"); while (listOfEmployee.hasNext()) { System.out.println("*************************"); Employee emp = listOfEmployee.next(); System.out.println("Employee Name : " + emp.name); System.out.println("Employee Position : " + emp.position); System.out.println("Employee Salary : " + emp.salary); } } // create an Employee Object with name, // position and salary as an attribute public class Employee { public String name; public String position; public String salary; Employee(String name, String position, String salary) { this.name = name; this.position = position; this.salary = salary; } public String toString() { return "Employee [name=" + name + ", position=" + position + ", salary=" + salary + "]"; } } // Main Method public static void main(String[] args) { GFG gfg = new GFG(); gfg.collectIterator(); }}Output:
list of Employees: ************************* Employee Name : Sachin Employee Position : Developer Employee Salary : 39000 ************************* Employee Name : Sanjeev Employee Position : Tester Employee Salary : 26000
