Java中的BlockingDeque contains()方法及示例

BlockingDeque 的 contains(Object o) 方法检查参数中传递的元素是否存在于容器中。如果该元素存在于容器中，则返回真，否则返回假值。

语法

public boolean contains(Object o)

参数： 该方法接受一个强制性参数 o ，该参数在容器中的存在要在容器中检查。

返回： 如果该元素存在，该方法返回true，否则返回false。

注意 ： BlockingDeque 的contains()方法已经从Java的LinkedBlockingDeque类中继承。

下面的程序说明了BlockingDeque的contains()方法。

程序1 :

// Java Program Demonstrate contains()
// method of BlockingDeque
  
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.BlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of BlockingDeque
        BlockingDeque<Integer> BD
            = new LinkedBlockingDeque<Integer>();
  
        // Add numbers to end of BlockingDeque
        BD.add(10);
        BD.add(20);
        BD.add(30);
        BD.add(40);
  
        // before removing print Deque
        System.out.println("Blocking Deque: " + BD);
  
        // check for presence using function
        if (BD.contains(10)) {
            System.out.println("Blocking Deque contains 10");
        }
        else {
            System.out.println("Blocking Deque does not contain 10");
        }
    }
}

输出。

Blocking Deque: [10, 20, 30, 40]
Blocking Deque contains 10

程序2 :

// Java Program Demonstrate contains()
// method of BlockingDeque
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.BlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of BlockingDeque
        BlockingDeque<String> BD
            = new LinkedBlockingDeque<String>();
  
        // Add numbers to end of BlockingDeque
        BD.add("ab");
        BD.add("cd");
        BD.add("fg");
        BD.add("xz");
  
        // before removing print Deque
        System.out.println("Blocking Deque: " + BD);
  
        // check for presence using function
        if (BD.contains("go")) {
            System.out.println("Blocking Deque contains 'go'");
        }
        else {
            System.out.println("Blocking Deque does not contain 'go'");
        }
    }
}

输出。

Blocking Deque: [ab, cd, fg, xz]
Blocking Deque does not contain 'go'

**参考资料: **https: //docs.oracle.com/javase/7/docs/api/java/util/concurrent/LinkedBlockingDeque.html#contains(java.lang.Object)