?1. 繼承?Thread?類?

• ?原理?：通過繼承?Thread?類并重寫?run()?方法定義線程任務，調用?start()?啟動線程?。
• ?代碼示例?：

  public class MyThread extends Thread {@Overridepublic void run() {System.out.println("線程 " + getName() + " 執行");for (int i = 0; i < 5; i++) {System.out.println(getName() + ":" + i);}}public static void main(String[] args) {MyThread t1 = new MyThread();MyThread t2 = new MyThread();t1.start();t2.start();}
  }
  

  ?缺點?：單繼承限制，無法繼承其他類?。

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?2. 實現?Runnable?接口?

• ?原理?：將線程任務解耦，通過?Runnable?對象傳遞給?Thread?構造函數?。
• ?代碼示例?：

  public class RunnableDemo implements Runnable {@Overridepublic void run() {for (int i = 0; i < 5; i++) {System.out.println(Thread.currentThread().getName() + ":" + i);}}public static void main(String[] args) {Runnable task = new RunnableDemo();Thread t1 = new Thread(task, "Thread-1");Thread t2 = new Thread(task, "Thread-2");t1.start();t2.start();}
  }
  

  ?優勢?：支持多接口實現，適合資源共享場景?。

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?3. 使用?Callable?和?Future?

• ?原理?：通過?Callable?接口定義可返回結果的任務，配合?FutureTask?獲取異步計算結果?。
• ?代碼示例?：

  import java.util.concurrent.*;public class CallableDemo implements Callable<Integer> {@Overridepublic Integer call() throws Exception {int sum = 0;for (int i = 0; i < 5; i++) {sum += i;}return sum;}public static void main(String[] args) throws ExecutionException, InterruptedException {ExecutorService executor = Executors.newSingleThreadExecutor();Future<Integer> future = executor.submit(new CallableDemo());System.out.println("計算結果：" + future.get());executor.shutdown();}
  }
  

  ?特點?：支持返回值，可處理異常?。

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?4. 線程池（ExecutorService）?

• ?原理?：通過線程池管理線程生命周期，減少資源開銷?。
• ?代碼示例?：

  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;public class ThreadPoolDemo {public static void main(String[] args) {ExecutorService pool = Executors.newFixedThreadPool(2);for (int i = 0; i < 5; i++) {pool.submit(() -> {System.out.println(Thread.currentThread().getName() + " 執行任務");});}pool.shutdown();}
  }
  

  ?優勢?：提高線程復用率，控制并發數量?。

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?總結?

?實現方式?	?適用場景?
繼承?Thread	簡單任務，無需資源共享
實現?Runnable	多接口、資源共享
Callable/Future	需要返回結果或處理異常
線程池	高并發、資源復用