Callable与Runnable的区别记录

Dear 丶 2021-09-24 03:58 324阅读 0赞

### 实现Callable或Runnable接口，实现他们对应的方法 ###

### 接口定义 ###

\#Callable接口

public interface Callable<V> {
        V call() throws Exception;
    }

\#Runnable接口

public interface Runnable {
        public abstract void run();
    }

### 相同点 ###

都是接口

都可以编写多线程程序

都采用Thread.start()启动线程

### 不同点 ###

Runnable没有返回值；Callable可以返回执行结果，是个泛型，和Future、FutureTask配合可以用来获取异步执行的结果

Callable接口的call()方法允许抛出异常；Runnable的run()方法异常只能在内部消化，不能往上继续抛

**注**：Callalble接口支持返回执行结果，需要调用FutureTask.get()得到，此方法会阻塞主进程的继续往下执行，如果不调用不会阻塞

**自定义调用记录，我需要实现短信的多线程发送还要判断返回值是否成功**

多线程实现层

public ExecutorService executorService = Executors.newCachedThreadPool();
    
        @Override//当前方法没返回值
        public void sendMessage(String numbers, String content,
                                String signature) {
    
            new Thread(new SendThread(numbers, content, signature)).start();
        }
    
    
        @Override//次方法有返回值
        public String sendMultiMessage(String numbers, String content,
                                       String signature, String sendCode) {
    
                Future<String> result = executorService.submit(new FutureMessage(numbers, content, signature, sendCode));
                try {
                    return result.get();
                } catch (InterruptedException | ExecutionException e) {
                    e.printStackTrace();
                }
    
            return "";
        }

初始话FutureMessage类，FutureMessage类实现了callable

public class FutureMessage implements Callable<String> {
        SendMessage sendMessage;
        String phoneNums;
        String content;
        String signature;
        String sendCode;
    
        public FutureMessage(String phoneNums, String content, String signature,String sendCode) {
            this.phoneNums = phoneNums;
            this.content = content;
            this.signature = signature;
            this.sendCode = sendCode;
        }
    
        @Override
        public String call() {
            String[] phoneNum = phoneNums.split(",");
            String smsContent = content;
    //        if (content.length() > 140) {
    //            smsContent = content.substring(0,140);
    //        }
            String sendStatus = "";
            //默认状态是1，发送成功的时候修改状态为0，异常时send值为2
            for (int i = 0; i < phoneNum.length; i++) {
                sendMessage = new SendMessage();
                int send = 1;
                try {
                    send = sendMessage.send(phoneNum[i], smsContent,this.sendCode);
                } catch (IOException e) {
                    e.printStackTrace();
                    send = 2;
                }
                if (sendStatus.equals("")) {
                    sendStatus = sendStatus + phoneNum[i] + ":" + send;
                } else {
                    sendStatus = sendStatus + "," + phoneNum[i] + ":" + send;
                }
            }
            return sendStatus;
        }
    
    }

至此进入短信发送的方法send

第二种SendThread类实现了Runnable没有返回值的线程调用，方法如下

public class SendThread implements Runnable {
        SendMessage sendMessage;
        String phoneNums;
        String content;
        String signature;
    
        public SendThread(String phoneNums, String content, String signature) {
            this.phoneNums = phoneNums;
            this.content = content;
            this.signature = signature;
        }
    
        @Override
        public void run() {
            String[] phoneNum = phoneNums.split(",");
            String smsContent = content;
            if (content.length() > 120) {
                smsContent = content.substring(120);
            }
    
            for (int i = 0; i < phoneNum.length; i++) {
                sendMessage = new SendMessage();
                try {
                    sendMessage.send(phoneNum[i], smsContent, "");
    
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                }
            }
            //每两次内容发送间间隔10秒，以免短信顺序错误
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    
    }