Java中的 BlockingQueue put() 方法及示例
如果队列未满, BlockingQueue接口的put(E e)方法会将作为参数传递给方法的元素插入此 BlockingQueue 的尾部。如果队列已满,则此方法将等待空间可用,并在空间可用后将元素插入 BlockingQueue。
句法:
public void put(E e) throws InterruptedException
参数:这个方法需要一个强制参数e ,它是要插入LinkedBlockingQueue的元素。
返回值:该方法不返回任何内容。
异常:此方法抛出以下异常:
- InterruptedException – 在等待队列可用时发生中断
- NullPointerException – 如果传递给方法的元素为 null
注意: BlockingQueue的put()方法继承自Java中的Queue类。
下面的程序说明了 BlockingQueue 类的 put(E e) 方法:
方案一:
Java
// Java Program Demonstrate put(E e)
// method of BlockingQueue
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class GFG {
public static void main(String[] args)
throws InterruptedException
{
// define capacity of BlockingQueue
int capacityOfQueue = 4;
// create object of BlockingQueue
BlockingQueue BQ
= new LinkedBlockingQueue(capacityOfQueue);
// Add element using put() method
BQ.put("Karan");
BQ.put("Suraj");
BQ.put("Harsh");
BQ.put("Rahul");
// print elements of queue
System.out.println("Items in Queue are " + BQ);
}
}
Java
// Java Program Demonstrate put()
// method of BlockingQueue
import java.util.Iterator;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class GFG {
public void PutDemo() throws InterruptedException
{
// define capacity of BlockingQueue
int capacityOfQueue = 5;
// create object of BlockingQueue
BlockingQueue BQ
= new LinkedBlockingQueue(capacityOfQueue);
// Add element to BlockingQueue
Employee emp1 = new Employee("Ranjeet", "Tester", "29000", 27);
Employee emp2 = new Employee("Sanjeet", "Manager", "98000", 34);
Employee emp3 = new Employee("Karan", "Analyst", "44000", 30);
// Add Employee Objects to BQ
// Using put(E e)
BQ.put(emp1);
BQ.put(emp2);
BQ.put(emp3);
System.out.println("Details of Employees:");
// print details of BQ
Iterator itr = BQ.iterator();
while (itr.hasNext())
System.out.println(itr.next());
}
// create an Employee Object with name,
// position, salary and age as attributes
public class Employee {
public String name;
public String position;
public String salary;
public int Age;
Employee(String name, String position,
String salary, int age)
{
this.name = name;
this.position = position;
this.salary = salary;
this.Age = age;
}
@Override
public String toString()
{
return "Employee [name=" + name + ", position="
+ position + ", salary=" + salary
+ ", Age=" + Age + "]";
}
}
// Main Method
public static void main(String[] args)
{
GFG gfg = new GFG();
try {
gfg.PutDemo();
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Java
// Java Program Demonstrate put(E e)
// method of BlockingQueue
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class GFG {
public static void main(String[] args)
throws InterruptedException
{
// define capacity of BlockingQueue
int capacityOfQueue = 4;
// create object of BlockingQueue
BlockingQueue BQ
= new LinkedBlockingQueue(capacityOfQueue);
// try to put null value in put method
try {
BQ.put(null);
}
catch (Exception e) {
// print error details
System.out.println("Exception: " + e);
}
}
}
输出:
Items in Queue are [Karan, Suraj, Harsh, Rahul]
方案二:
Java
// Java Program Demonstrate put()
// method of BlockingQueue
import java.util.Iterator;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class GFG {
public void PutDemo() throws InterruptedException
{
// define capacity of BlockingQueue
int capacityOfQueue = 5;
// create object of BlockingQueue
BlockingQueue BQ
= new LinkedBlockingQueue(capacityOfQueue);
// Add element to BlockingQueue
Employee emp1 = new Employee("Ranjeet", "Tester", "29000", 27);
Employee emp2 = new Employee("Sanjeet", "Manager", "98000", 34);
Employee emp3 = new Employee("Karan", "Analyst", "44000", 30);
// Add Employee Objects to BQ
// Using put(E e)
BQ.put(emp1);
BQ.put(emp2);
BQ.put(emp3);
System.out.println("Details of Employees:");
// print details of BQ
Iterator itr = BQ.iterator();
while (itr.hasNext())
System.out.println(itr.next());
}
// create an Employee Object with name,
// position, salary and age as attributes
public class Employee {
public String name;
public String position;
public String salary;
public int Age;
Employee(String name, String position,
String salary, int age)
{
this.name = name;
this.position = position;
this.salary = salary;
this.Age = age;
}
@Override
public String toString()
{
return "Employee [name=" + name + ", position="
+ position + ", salary=" + salary
+ ", Age=" + Age + "]";
}
}
// Main Method
public static void main(String[] args)
{
GFG gfg = new GFG();
try {
gfg.PutDemo();
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
输出:
Details of Employees:
Employee [name=Ranjeet, position=Tester, salary=29000, Age=27]
Employee [name=Sanjeet, position=Manager, salary=98000, Age=34]
Employee [name=Karan, position=Analyst, salary=44000, Age=30]
方案 3:
Java
// Java Program Demonstrate put(E e)
// method of BlockingQueue
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class GFG {
public static void main(String[] args)
throws InterruptedException
{
// define capacity of BlockingQueue
int capacityOfQueue = 4;
// create object of BlockingQueue
BlockingQueue BQ
= new LinkedBlockingQueue(capacityOfQueue);
// try to put null value in put method
try {
BQ.put(null);
}
catch (Exception e) {
// print error details
System.out.println("Exception: " + e);
}
}
}
输出:
Exception: java.lang.NullPointerException
参考: https: Java/util/concurrent/BlockingQueue.html#put(E)