分类后的葵花宝典java基础day11线程

图上的一键优化与清除同时在运行，在一个进程中同时在执行了多个任务。CPU开销。线程的使用会给系统带来上下文切换的额外负问题：先按照顺序运行完了然后接着再按照顺序运行完，我们想要的效果是runrun问题：先按照顺序运行完了然后接着再按照顺序运行完，我们想要的效果是run()JVN不会当作线程来运行，会认为是普通的方Thread类的对象并启动该线程，但是如果没有重写run()，什么也不线程池中，变得可运行，等待获取cpu的执行权。阻塞:CPU使用权，暂时停止运行。直到线程进入就绪Thread(Stringname) setName(Stringname) 默认线程的优先级是5setPriority(intnewPriority)设置线程的优先级 现取决于底层的操作系统的实现（最大的优先级是10，最小的1，默认是5 sleep(int classThreadDemo1extends{public}publicThreadDemo1(Stringnamesuper(name}publicvoidrun(){inti=0;while(i<30){System.out.println(this.getName()+""+":i="+i);System.out.println(Thread.currentThread().getName()+""+":i="+System.out.println(Thread.currentThread()==this);System.out.println("getId()"+""+":id="+super.getId()System.out.println("getPriority()"+""+":Priority=+super.getPriority()}}}class{publicstaticvoidmain(String[]{ThreadDemo1th1newThreadDemo1("线程1");ThreadDemo1th2newThreadDemo1("线程th1.setName("th1"th2.setName("th2"设置线程优先级1~th1.setPriority(10th2.setPriority(7System.out.println("max:"+Thread.MAX_PRIORITY);System.out.println("min:"+Thread.MIN_PRIORITY);System.out.println("nor:"+Thread.NORM_PRIORITY); o}}都了属于自己的tickets属性，那么就总共存在了四份。解决方案一：tickets使用staitc修饰，使每个线程对象都是共份属性Runnablerun方法packagepackagepublicclassDemo1publicstaticvoidmain(String[]args){MyRunmy=newMyRun();Threadt1=newThread(my);for(inti=0;i<200;i++){System.out.println("main:"+i);}}}classMyRunimplementsRunnablepublicvoidrun()for(inti=0;i<200;i++){System.err.println("MyRun:"+i);}}}执行的代码.RunnableThread的构造时,实际上就是让给Threadrun方法,Thread一项任务.Thread.slee（100classclassMyTicketimplementsRunnableinttickets=publicvoidrun()while(true)if(tickets>0)try}catch(InterruptedExceptione){}System.out.println(Thread.currentThread().getName()tickets号票");}else}}}}publicclassDemo6publicstaticvoidmain(String[]args){MyTicketmt=newMyTicket();Threadt1=newThread(mt);Threadt2=newThread(mt);Threadt3=newThread(mt);Threadt4=newThread(mt);}}每个java对象都有一个锁对象.而且只有一把类名对象（52T1L1T2L2T1L2T2publicclassDeadLockpublicstaticvoidmain(String[]args)newThread(newRunnable(创建线程publicvoidrun()synchronized("刀叉"){ 你不给我筷子我就不给你刀叉try}catch(InterruptedExceptione){}synchronized("筷子.getName(给你刀叉}}}}, newThread(newRunnable( publicvoidrun()synchronized("筷子"){ 你先给我刀叉我再给你筷子try}catch(InterruptedExceptione){}synchronized("刀叉.getName()+":好吧,把筷子给你}}} 人}}whilenotifyAll唤醒，notify容易出现只唤醒本方线程情况，导致程序中的所有线程都在等待。，publicpublicclassDemo10publicstaticvoidmain(String[]args){p=new Producerpro=newProducer(p);Consumercon=newConsumer(p);Threadt1newThread(pro生产者");Threadt2newThread(con消费者");}} {StringString}classProducerimplementsRunnable{publicProducer()}publicthis.p=}p)publicvoidrun(){inti=0;while(true){if(i%2==publicvoidrun(){inti=0;while(true){if(i%2==0)="jack";p.gender="man";}= p.gender女}}}classConsumerimplementsRunnable{publicConsumer()}publicthis.p=}p)publicvoidrun()while(true)System.out.println("name:"++"---gnder:"}}}Producer和Consumer对象所以Producer和Consumer的是同一个 显然屏幕输出了man这样的结果是出现了线程安全问题。所以需要使用packagepackagepublicclassDemo10publicstaticvoidmain(String[]args){p=new Producerpro=newProducer(p);Consumercon=newConsumer(p);Threadt1newThread(pro生产者");Threadt2newThread(con消费者");}} {StringString}classProducerimplementsRunnable{publicProducer()}public p)this.p=}publicvoidrun(){inti=0;while(true){synchronized(p)if(i%2==0)="jack";p.gender="man";}= p.gender女}}}}classConsumerimplementsRunnable{publicConsumer()}public p)this.p=}publicvoidrun()while(true)synchronized(p)System.out.println("name:"++"---gnder:"}}}}jack女或者manpublicpublicclassDemo10publicstaticvoidmain(String[]args){p=new Producerpro=newProducer(p);Consumercon=newConsumer(p);Threadt1newThread(pro生产者");Threadt2newThread(con消费者");}} {StringStringpublicsynchronizedvoidset(Stringname,Stringgender)=this.gender=}publicsynchronizedvoidread(){System.out.println("name:"++"----gender:"+}}classProducerimplementsRunnable{publicProducer()}public p)this.p=}publicvoidrun(){inti=0;while(true){if(i%2==0)p.set("jack",}else 女}}}classConsumerimplementsRunnable{publicConsumer()}publicpublicthis.p=}p)publicvoidrun()while(true){}}}有获得执行权，并持有了相同的监视器（锁）并调用notify为止。notify：唤醒持有同一个监视器（锁）wait的第一个线程，例如，餐馆有空位置packagepackagepublicclassDemo10publicstaticvoidmain(String[]args){p=new Producerpro=newConsumercon=newThreadt1newThread(pro生产者");Threadt2newThread(con消费者");}}//使 Stringname;Stringgender;booleanflag=publicsynchronizedvoidset(Stringname,Stringgender)if(flag)try}catch(InterruptedExceptione)}}=name;this.gender=gender;flag=true;}publicsynchronizedvoidread()if(!flag)try}catch(InterruptedExceptione)}}System.out.println("name:"++"----gender:"flag=false;}}classProducerimplementsRunnable{publicProducer()}public p)this.p=}publicvoidrun(){inti=0;while(true){if(i%2==0)p.set("jack",}else 女}}}classConsumerimplementsRunnable{publicConsumer()}public p)this.p=}publicpublicvoidrun()while(true){}}}waitnotif（，Object类中waitsleep()2.正常终止当线程的run()执行完毕，线程注意：Stop方法已过时，就不能再使用这个方法。run方法结束，classclassStopThreadimplementsRunnable{publicbooleantag=true;publicvoidrun()inti=while(tag)"i:"+}}}publicclassDemo8publicstaticvoidmain(String[argsStopThreadst=newStopThread();Threadth=newThread(st,"线程1");for(inti=0;i<100;i++)if(i==50){System.out.println("maini:"+i);st.tag=false;}}}}3.线setDaemon(boolean必须在启动线程之前（start方法之前）setDaemon（true）方法，才可以把main（）执行完毕，那么程序就会终止，JVM也就退出了。该案例：开启了一个qq检测升级的线程，通过while真循环进行不停检测，当计数100的时候，表示检测完毕，提示是否更新，线程同时结束。classQQUpdateimplementsRunnableinti=classQQUpdateimplementsRunnableinti=publicvoidrun()while(true)System.out.println(Thread.currentThread().getName()+try}catch(InterruptedExceptione)}if(i==10