004.多线程-线程的三种创建方式

心已赠人 2021-10-06 15:26 441阅读 0赞

### 1. extend Thread ###

package cn.qbz.thread;
    
    public class ExtendThreadTest { 
        public static void main(String[] args) { 
            ExtendThread thread = new ExtendThread();
            thread.start();
            for (int i = 0; i < 300; i++) { 
                System.out.println("主线程：" + Thread.currentThread().getName() + " " + i);
            }
        }
    }
    
    class ExtendThread extends Thread { 
        @Override
        public void run() { 
            for (int i = 0; i < 300; i++) { 
                System.out.println("子线程：" + this.getName() + " " + i);
            }
        }
    }

![idea64_2018-11-14_11-29-03.png][]

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### 2. implement Runnable ###

package cn.qbz.thread;
    
    public class ImplementRunnableTest { 
        public static void main(String[] args) { 
            ImplementRunnable runnable = new ImplementRunnable();
            Thread thread = new Thread(runnable);
            thread.start();
    
            for (int i = 0; i < 300; i++) { 
                System.out.println("主线程：" + Thread.currentThread().getName() + " " + i);
            }
        }
    }
    
    class ImplementRunnable implements Runnable { 
    
        public void run() { 
            for (int i = 0; i < 300; i++) { 
                System.out.println("子线程：" + Thread.currentThread().getName() + " " + i);
            }
        }
    }

![idea64_2018-11-14_11-34-56.png][]

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### 3.implement Callable ###

package cn.qbz.thread;
    
    import java.util.concurrent.Callable;
    import java.util.concurrent.ExecutionException;
    import java.util.concurrent.FutureTask;
    import java.util.concurrent.TimeoutException;
    
    public class ImplementCallableTest { 
        public static void main(String[] args) { 
            ImplementCallable callable = new ImplementCallable(666);
            FutureTask<Integer> futureTask = new FutureTask<Integer>(callable);
            Thread thread = new Thread(futureTask);
            thread.start();
    
            for (int i = 0; i < 300; i++) { 
                System.out.println("主线程：" + Thread.currentThread().getName() + " " + i);
            }
    
            try { 
                System.out.println("子线程返回值：" + futureTask.get());
            } catch (InterruptedException e) { 
                System.out.println("eeeeeeeeeeeeee222....." + e.getMessage());
            } catch (ExecutionException e) { 
                System.out.println("eeeeeeeeeeeeee....." + e.getMessage());
            }
            for (int j = 0; j < 10; j++) { 
                System.out.println("jjjjjjjjjjj " + j);
            }
        }
    }
    
    class ImplementCallable implements Callable<Integer> { 
        private Integer result;
    
        public ImplementCallable(Integer result) { 
            this.result = result;
        }
    
        public Integer call() throws Exception { 
            for (int i = 0; i < 300; i++) { 
                System.out.println("子线程：" + Thread.currentThread().getName() + " " + i);
                if (i == 268) { 
                    throw new TimeoutException();
                }
            }
            return result;
        }
    }

![idea64_2018-11-14_11-59-45.png][]

1.  Implement Callable,重写call方法，不但可以返回值，还可以抛出异常。
2.  抛出的异常，在futureTask.get()中被捕获
3.  futureTask.get()在执行的过程中会阻塞，一直到所在线程执行结束
4.  futureTask还有相关方法来进行了解线程的执行情况

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### 三种创建方式的比较： ###

当前主流的就是面向接口开发，  
因为实现了接口后还可以根据业务需要再继承其他的类。  
实现Runnable接库与实现Callable接口对比来看，  
Callable接口有几个优势，也就是上面所说的：  
可返回值，可抛出异常，可了解线程执行情况。

[idea64_2018-11-14_11-29-03.png]: http://upyun.qubianzhong.cn/picture/idea64_2018-11-14_11-29-03.png
[idea64_2018-11-14_11-34-56.png]: http://upyun.qubianzhong.cn/picture/idea64_2018-11-14_11-34-56.png
[idea64_2018-11-14_11-59-45.png]: http://upyun.qubianzhong.cn/picture/idea64_2018-11-14_11-59-45.png