最近换了一套教程,
Java -Java 学习- Java 基础到高级-宋红康-零基础自学Java-尚硅谷:https://www.bilibili.com/video/av48370019/?p=445
学习java语言的高级部分,主要学习内容有:
课程配套资料(视频链接下UP主置顶评论):
链接:https://pan.baidu.com/s/1si0uLgy4HpyCM7SbCt82GA
提取码:hiw3
以下为个人笔记
部分代码:
线程安全的单例模式:
class Bank{
private Bank(){}
private static Bank instance = null;
public static Bank getInstance(){
//方式一:效率稍差
// synchronized (Bank.class) {
// if(instance == null){
//
// instance = new Bank();
// }
// return instance;
// }
//方式二:效率更高
if(instance == null){
synchronized (Bank.class) {
if(instance == null){
instance = new Bank();
}
}
}
return instance;
}
}
使用Callable创建线程:
//1.创建一个实现Callable的实现类
class NumThread implements Callable{
//2.实现call方法,将此线程需要执行的操作声明在call()中
@Override
public Object call() throws Exception {
int sum = 0;
for (int i = 1; i <= 100; i++) {
if(i % 2 == 0){
System.out.println(i);
sum += i;
}
}
return sum;
}
}
public class ThreadNew {
public static void main(String[] args) {
//3.创建Callable接口实现类的对象
NumThread numThread = new NumThread();
//4.将此Callable接口实现类的对象作为传递到FutureTask构造器中,创建FutureTask的对象
FutureTask futureTask = new FutureTask(numThread);
//5.将FutureTask的对象作为参数传递到Thread类的构造器中,创建Thread对象,并调用start()
new Thread(futureTask).start();
try {
//6.获取Callable中call方法的返回值
//get()返回值即为FutureTask构造器参数Callable实现类重写的call()的返回值。
Object sum = futureTask.get();
System.out.println("总和为:" + sum);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
}
使用线程池:
class NumberThread implements Runnable{
@Override
public void run() {
for(int i = 0;i <= 100;i++){
if(i % 2 == 0){
System.out.println(Thread.currentThread().getName() + ": " + i);
}
}
}
}
class NumberThread1 implements Runnable{
@Override
public void run() {
for(int i = 0;i <= 100;i++){
if(i % 2 != 0){
System.out.println(Thread.currentThread().getName() + ": " + i);
}
}
}
}
public class ThreadPool {
public static void main(String[] args) {
//1. 提供指定线程数量的线程池
ExecutorService service = Executors.newFixedThreadPool(10);
ThreadPoolExecutor service1 = (ThreadPoolExecutor) service;
//设置线程池的属性
// System.out.println(service.getClass());
// service1.setCorePoolSize(15);
// service1.setKeepAliveTime();
//2.执行指定的线程的操作。需要提供实现Runnable接口或Callable接口实现类的对象
service.execute(new NumberThread());//适合适用于Runnable
service.execute(new NumberThread1());//适合适用于Runnable
// service.submit(Callable callable);//适合使用于Callable
//3.关闭连接池
service.shutdown();
}
}