Java 多執行緒程式是什麼意思?
多執行緒程式由兩個或更多部分構成,這些部分可以同時執行,每個部分都可以處理不同的任務,充分利用可用資源,特別是在你的計算機擁有多個 CPU 的情況下。
多執行緒讓你可以編寫程式,其中的多個活動可以在同一個程式中同時執行。
示例
class RunnableDemo implements Runnable { private Thread t; private String threadName; RunnableDemo( String name) { threadName = name; System.out.println("Creating " + threadName); } public void run() { System.out.println("Running " + threadName); try { for(int i = 4; i > 0; i--) { System.out.println("Thread: " + threadName + ", " + i); // Let the thread sleep for a while. Thread.sleep(50); } } catch (InterruptedException e) { System.out.println("Thread " + threadName + " interrupted."); } System.out.println("Thread " + threadName + " exiting."); } public void start () { System.out.println("Starting " + threadName ); if (t == null) { t = new Thread (this, threadName); t.start (); } } } public class TestThread { public static void main(String args[]) { RunnableDemo R1 = new RunnableDemo( "Thread-1"); R1.start(); RunnableDemo R2 = new RunnableDemo( "Thread-2"); R2.start(); } }
輸出
Creating Thread-1 Starting Thread-1 Creating Thread-2 Starting Thread-2 Running Thread-1 Thread: Thread-1, 4 Running Thread-2 Thread: Thread-2, 4 Thread: Thread-1, 3 Thread: Thread-2, 3 Thread: Thread-1, 2 Thread: Thread-2, 2 Thread: Thread-1, 1 Thread: Thread-2, 1 Thread Thread-1 exiting. Thread Thread-2 exiting.
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