java - 启动时线程未运行

Question

任务与在桥上行驶的汽车有关，它们向东和向西行驶。它应该避免死锁。我需要知道的是如何真正让它显示，因为它正在编译和技术上运行（只是不显示任何东西）。我目前将所有内容都保存在一个文件中。它需要在某个地方分开吗？我不知道。

import java.util.concurrent.*;
public class Cars {
    //creating a static class to create variables
    static class ExtendThread extends Thread {
        //create variables
        Semaphore sem;
        String name;

        //creating a public class for the ExtendThread
        public ExtendThread(Semaphore sem, String name) {
            super(name);
            //creating instance variables for the current class
            this.sem = sem;
            this.name = name;
        }

        //creating an area to run the simulation
        public void go() {
            //creating an if statement for the westbound cars  
            if (this.getName().equals("Westbound Cars")) {
                //creating a try to make sure there are no interrupted exceptions
                try {
                    //print statement for who is waiting
                    System.out.println(name + " are waiting to cross.");

                    //acquiring the semaphore
                    sem.acquire();

                    //print statement for who is attempting to cross
                    System.out.println(name = " are attempting to cross.");

                    //a for statement to allow individual westbound cars to cross or wait more
                    for (int i = 1; i < 9; i++) {
                        //print statement to show which car(from 1-9) is still waiting
                        System.out.println("Westbound car " + i + " is waiting to cross.");
                        Thread.sleep(1000);

                        //print statement to show which car(from 1-9) has crossed
                        System.out.println("Westbound car " + i + " has crossed.");
                        Thread.sleep(1000);
                    }
                }
                //catch portion for the try-catch statement
                catch (InterruptedException exc) {
                    System.out.println(exc);
                }
                //print statement for who has crossed the bridge
                System.out.println(name + " have crossed the bridge.");
                //releasing the semaphore
                sem.release();
            }
            //creating an else statement for the eastbound cars
            else {
                //print statement for readibility
                System.out.println(name + " are waiting to cross the bridge.");

                //creating a try to make sure there are no interrupted exceptions
                try {
                    //print statement for who is waiting
                    System.out.println(name + " is waiting to cross.");

                    //acquiring the semaphore
                    sem.acquire();

                    //print statment for who is attempting to cross
                    System.out.println(name + " is attempting to cross.");

                    //a for statement to allow individual eastbound cars to cross or wait more
                    for (int i = 1; i < 9; i++) {
                        //print statement to show which car(from 1-9) is still waiting
                        System.out.println("Eastbound car " + i + " is waiting to cross.");
                        Thread.sleep(1000);

                        //print statement to show which car(from 1-9) has crossed
                        System.out.println("Eastbound car " + i + " has crossed.");
                        Thread.sleep(1000);
                    }
                }
                //catch portion for the try-catch statement
                catch (InterruptedException exc) {
                    System.out.println(exc);
                }
                //print statement for who has crossed the bridge
                System.out.println(name + " have crossed the bridge.");
                //releasing the semaphore
                sem.release();
            }
        }
    }
    //creating the main class
    public static void main(String [] args) throws InterruptedException {
        //creating a semaphore object with a single permit
        Semaphore sem = new Semaphore(1);

        //creating the cars
        ExtendThread exTh1 = new ExtendThread(sem,"Westbound Cars");
        ExtendThread exTh2 = new ExtendThread(sem,"Eastbound Cars");

        //running the program
        exTh1.start();
        exTh2.start();

        exTh1.join();
        exTh2.join();
    }
}

标签： java

Answer 1

您需要 Thread 的“run()”方法。或者您可以将方法重命名go为run

static class ExtendThread extends Thread {
      @Override
      public void run() {
          this.go();
      }
}