创建线程的几种方法
继承Thread
继承Thread类并重写run()方法，
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| public class TestThread extends Thread {
@Override
public void run() {
super.run();
for (int i = 0; i < 20; i++) {
System.out.println(i);
}
}
}
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创建TestThread对象，并调用start()方法
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| public static void main(String[] args) {
TestThread testThread = new TestThread();
testThread.start();
}
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如果逻辑并不复杂，可以直接创建Thread对象并重写run()方法
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| public static void main(String[] args) {
new Thread() {
@Override
public void run() {
super.run();
for (int i = 0; i < 20; i++) {
System.out.println(i);
}
}
}.start();
}
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实现Runnable
实现Runnable接口并重写run()方法
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| public class TestRunnable implements Runnable {
@Override
public void run() {
for (int i = 0; i < 20; i++) {
System.out.println(i);
}
}
}
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创建TestRunnable对象，创建Thread对象，并传入TestRunnable对象
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| public static void main(String[] args) {
TestRunnable testRunnable = new TestRunnable();
new Thread(testRunnable).start();
}
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或者直接传入匿名类
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| public static void main(String[] args) {
new Thread(new Runnable() {
@Override
public void run() {
for (int i = 0; i < 20; i++) {
System.out.println(i);
}
}
}).start();
}
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注意：如果在创建Thread对象时，传入Runnable同时重写run()方法，那么它们两个都会被执行
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| public static void main(String[] args) {
new Thread(new Runnable() {
@Override
public void run() {
System.out.println("执行Runnable匿名类的run方法");
}
}) {
@Override
public void run() {
super.run();
System.out.println("执行重写run方法");
}
}.start();
}
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实现Callable
实现Callable类,重写run()方法并指定其泛型类型
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| public class TestCallable implements Callable<String> {
@Override
public String call() throws Exception {
return "测试";
}
}
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创建FutureTask对象，并传入TestCallable，将FutureTask放在Thread中执行，执行后通过FutureTask的get()方法可以获取到TestCallable的返回值
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| public static void main(String[] args) {
TestCallable testCallable = new TestCallable();
FutureTask<String> futureTask = new FutureTask<>(testCallable);
new Thread(futureTask).start();
try {
String s = futureTask.get();
System.out.println(s);
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
|