循环读取concurrentlinkedqueue集合中的字符串
时间: 2024-05-21 11:12:42 浏览: 16
可以使用Java中的ConcurrentLinkedQueue的poll()方法循环读取队列中的字符串。使用while循环,如果队列不为空,则从队列中取出一个元素(即字符串),并进行相应的处理,直到队列为空为止。示例代码如下:
ConcurrentLinkedQueue<String> queue = new ConcurrentLinkedQueue<>();
//将字符串加入队列中
queue.add("str1");
queue.add("str2");
queue.add("str3");
//循环读取队列中的字符串
while(!queue.isEmpty()){
String str = queue.poll(); //获取并移除队列的头,如果队列为空,则返回null
//进行相应的处理
System.out.println(str);
}
相关问题
写一个java代码多线程应用循环顺序读取concurrentlinkedqueue中的值
好的,以下是示例代码:
```java
import java.util.concurrent.ConcurrentLinkedQueue;
public class Example {
public static void main(String[] args) {
ConcurrentLinkedQueue<String> queue = new ConcurrentLinkedQueue<String>();
queue.add("value1");
queue.add("value2");
queue.add("value3");
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
while (!queue.isEmpty()) {
String value = queue.poll();
if (value != null) {
System.out.println("Thread 1: " + value);
}
}
}
});
Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
while (!queue.isEmpty()) {
String value = queue.poll();
if (value != null) {
System.out.println("Thread 2: " + value);
}
}
}
});
t1.start();
t2.start();
}
}
```
在此示例中,我们创建了一个`ConcurrentLinkedQueue`并添加了一些值。然后,我们启动两个线程`t1`和`t2`来循环读取队列中的值。每个线程从队列中获取值并打印出来,直到队列为空。注意,由于`ConcurrentLinkedQueue`是线程安全的,因此我们可以在多个线程之间安全地共享它。
使用java写一个多线程读取concurrentlinkwdqueue中的字符串样例
Sure, I can help you with that! Here is a sample code in Java for reading strings from a `ConcurrentLinkedQueue` using multiple threads:
```
import java.util.concurrent.ConcurrentLinkedQueue;
public class ConcurrentQueueReader {
// Shared queue to read from
private ConcurrentLinkedQueue<String> queue;
public ConcurrentQueueReader(ConcurrentLinkedQueue<String> queue) {
this.queue = queue;
}
// Method to be executed by each thread
private void readFromQueue() {
while (true) {
// Check if the queue is empty
if (queue.isEmpty()) {
try {
// Wait for a short period before trying again
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
} else {
// Retrieve the next string from the queue and process it
String str = queue.poll();
System.out.println(str);
}
}
}
// Start multiple threads to read from the queue
public void startReading(int numThreads) {
for (int i = 0; i < numThreads; i++) {
Thread t = new Thread(() -> readFromQueue());
t.start();
}
}
}
```
To use this code, you can create an instance of `ConcurrentQueueReader` and pass your `ConcurrentLinkedQueue` as a parameter. Then, call the `startReading()` method to start multiple threads, each of which will read strings from the queue and process them. For example:
```
public static void main(String[] args) {
// Create a shared queue
ConcurrentLinkedQueue<String> queue = new ConcurrentLinkedQueue<>();
// Add some strings to the queue
queue.add("String 1");
queue.add("String 2");
queue.add("String 3");
// Create an instance of ConcurrentQueueReader and start reading from the queue
ConcurrentQueueReader reader = new ConcurrentQueueReader(queue);
reader.startReading(2); // Start 2 threads to read from the queue
}
```
This code will output the following:
```
String 1
String 2
String 3
```
And each string will be processed by one of the two threads that are reading from the queue. Note that the `ConcurrentQueueReader` class uses a `while` loop to continuously check the queue for new strings, and waits for a short period if the queue is empty. This ensures that each thread stays active and continues to read from the queue as new strings are added.