线程的创建之实现Callable接口

1. 过程

1. 实现Callable接口，需要返回值类型。
2. 重写call方法，需要抛出异常。
3. 创建目标对象
4. 创建执行任务：ExecutorService ser = Executors.newFixedThreadPool(1);。
5. 提交实行：Future<Boolean> result1 = ser.submit(t1);。
6. 获取结果：boolean r1 = result1.get()。
7. 关闭服务：ser.shutdownNow();。

2. 使用

public class Demo6 implements Callable<Boolean> {

    private String url;
    private String name;

    public Demo6(String url, String name) {
        this.url = url;
        this.name = name;
    }

    @Override
    public Boolean call() {
        new WebDownloader1().downloader(url, name);
        System.out.println("下载的文件名为" + name);
        return true;
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        Demo6 t1 = new Demo6("https://cdn.jsdelivr.net/gh/rootwhois/oss@main/uPic/image-20210820235038265.png", "1.png");
        Demo6 t2 = new Demo6("https://cdn.jsdelivr.net/gh/rootwhois/oss@main/uPic/image-20210820235038265.png", "2.png");
        Demo6 t3 = new Demo6("https://cdn.jsdelivr.net/gh/rootwhois/oss@main/uPic/image-20210820235038265.png", "3.png");

        ExecutorService executorService = Executors.newFixedThreadPool(3);

        Future<Boolean> submit = executorService.submit(t1);
        Future<Boolean> submit1 = executorService.submit(t2);
        Future<Boolean> submit2 = executorService.submit(t3);

        Boolean rs1 = submit.get();