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。如果元素存在于容器中，则返回 true，否则返回 false 值。

句法：

public boolean contains(Object o)

参数：此方法接受一个强制参数o ，它在容器中的存在将在容器中检查。

返回：如果元素存在，此方法返回 true，否则返回 false。

注意： BlockingDeque的 contains() 方法继承自Java中的 LinkedBlockingDeque 类。

下面的程序说明了 BlockingDeque 的 contains() 方法：

方案一：

// 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 BD
            = new LinkedBlockingDeque();
  
        // 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

方案二：

// 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 BD
            = new LinkedBlockingDeque();
  
        // 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： https: Java Java.lang.Object)