Java开发面经分享：Java多线程实现原理

怼烎@ 2022-09-03 00:27 201阅读 0赞

} catch (ExecutionException e) {
    
            e.printStackTrace();
    
        }

**a.使用线程实现方式**
    
    
    
    主要是将Callable的实例对象通过FutureTask包装了一下，可以看下FutureTask中构造方法的源码
    
    
    
    FutureTask 实现RunnableFuture接口，而RunnableFuture接口继承Runnable, Future接口
    
    
    
    因此FutureTask可以包装的Callable的实例中的call()在run()中执行，所以这种方式就等于将Runnable实现的子类实例放入到Thread的构造方法中，子类的run()方法正好是重写里面调用call();

public void run() \{

if (state != NEW ||
    
            !UNSAFE.compareAndSwapObject(this, runnerOffset,
    
                                         null, Thread.currentThread()))
    
            return;
    
        try {
    
            Callable<V> c = callable;
    
            if (c != null && state == NEW) {
    
                V result;
    
                boolean ran;
    
                try {
    
                    result = c.call();
    
                    ran = true;
    
                } catch (Throwable ex) {
    
                    result = null;
    
                    ran = false;
    
                    setException(ex);
    
                }
    
                if (ran)
    
                    set(result);
    
            }
    
        } finally {
    
            // runner must be non-null until state is settled to
    
            // prevent concurrent calls to run()
    
            runner = null;
    
            // state must be re-read after nulling runner to prevent
    
            // leaked interrupts
    
            int s = state;
    
            if (s >= INTERRUPTING)
    
                handlePossibleCancellationInterrupt(s);
    
        }
    
    }

**另外**，FutureTask的构造方法传入的参数除了Callable之外也支持Runnable，它的操作主要是将Runnable实现的子类通过RunnableAdapter转化为Callable，源码如下

public FutureTask(Runnable runnable, V result) \{

this.callable = Executors.callable(runnable, result);
    
        this.state = NEW;       // ensure visibility of callable
    
    }
    
    
    
    
    
    public static <T> Callable<T> callable(Runnable task, T result) {
    
        if (task == null)
    
            throw new NullPointerException();
    
        return new RunnableAdapter<T>(task, result);
    
    }

**b.使用线程池方式实现**

ThreadPoolExecutor threadPool = (ThreadPoolExecutor)Executors.newFixedThreadPool (10);

Callable callable = new Callable() {
    
            @Override
    
            public Object call() throws Exception {
    
                return "线程池实现方式";
    
            }
    
        };
    
        FutureTask<String> task = new FutureTask<>(callable);
    
        threadPool.submit(task);
    
        try {
    
            System.out.println(task.get());;
    
        } catch (InterruptedException e) {
    
            e.printStackTrace();

# Kafka实战笔记 #

> **关于这份笔记，为了不影响大家的阅读体验，我只能在文章中展示部分的章节内容和核心截图，如果你需要完整的pdf版本，[戳这里即可免费领取][Link 1]。**

![image.png][]

*  **Kafka入门**
 *  **为什么选择Kafka**
 *  **Karka的安装、管理和配置**

![image.png][image.png 1]

*  **Kafka的集群**
 *  **第一个Kafka程序**
 *  ![image.png][image.png 2]

afka的生产者

![image.png][image.png 3]

*  **Kafka的消费者**
 *  **深入理解Kafka**
 *  **可靠的数据传递**

![image.png][image.png 4]

![image.png][image.png 5]

*  **Spring和Kalka的整合**
 *  **Sprinboot和Kafka的整合**
 *  **Kafka实战之削峰填谷**
 *  **数据管道和流式处理(了解即可)**

![image.png][image.png 6]

*  **Kafka实战之削峰填谷**

![image.png][image.png 7]

ng和Kalka的整合\*\*

*  **Sprinboot和Kafka的整合**
 *  **Kafka实战之削峰填谷**
 *  **数据管道和流式处理(了解即可)**

\[外链图片转存中…(img-Ci9mvJ7V-1628071238903)\]

*  **Kafka实战之削峰填谷**

\[外链图片转存中…(img-Ah2TepCm-1628071238904)\]

[Link 1]: https://gitee.com/vip204888/java-p7
[image.png]: /images/20220829/9ab64329f59c49aba19e3729764f3033.png
[image.png 1]: /images/20220829/c6909271528f44de9cec48b5093b72bb.png
[image.png 2]: /images/20220829/38c4bdbb65364a0d8c564755eb1cda3a.png
[image.png 3]: /images/20220829/238c72768a99475681c1383266291b34.png
[image.png 4]: /images/20220829/fff615693773497f8420f7b0574b2ffb.png
[image.png 5]: /images/20220829/dcf4509c319342849ed8844c42ab4599.png
[image.png 6]: /images/20220829/7c8ba3872ab44af6b1a5261afdcdcf72.png
[image.png 7]: /images/20220829/748ca7c4984949c7bfb8dce84caa3c79.png