买票
/**
* 不安全买票测试
*/
public class NotSafeBuyTicket {
public static void main(String[] args) {
BuyTicket buyTicket = new BuyTicket();
Thread t1 = new Thread(buyTicket,"嘟嘟");
Thread t2 = new Thread(buyTicket,"肝肝");
Thread t3 = new Thread(buyTicket,"钢镚");
Thread t4 = new Thread(buyTicket,"核恒");
t1.start();
t2.start();
t3.start();
t4.start();
}
}
class BuyTicket implements Runnable{
private int ticket = 100;
private boolean flag = true;
@Override
public void run() {
while (flag){
buy();
}
}
// synchronized 同步锁
public synchronized void buy(){
if(ticket <= 0){
flag = false;
return ;
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()+"买到了票 :"+ticket--);
}
银行取钱
/**
* 不安全银行取钱测试
*/
public class NotSafeBank {
public static void main(String[] args) {
Account account = new Account(100,"结婚基金");
Bank g = new Bank(account, 50, "肝肝");
Bank d = new Bank(account, 100, "嘟嘟");
new Thread(g).start();
new Thread(d).start();
}
}
class Account{
int money;
String name;
public Account(int money,String name) {
this.money = money;
this.name = name;
}
}
class Bank implements Runnable{
private int out;
private int nowMoney;
private String name;
private Account account;
public Bank(Account account,int out, String name) {
this.out = out;
this.account = account;
this.name = name;
}
@Override
public void run() {
//同步块
synchronized (account){
account.money = account.money - out;
if(account.money < 0 ){
System.out.println(account.name +"钱不够了 取不了!");
return;
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
nowMoney = out;
System.out.println(this.name +"取到了"+nowMoney);
System.out.println(account.name+" 余额为:"+account.money);
}
}
}
集合
/**
* 不安全集合
*/
public class NotSafeList {
public static void main(String[] args) throws InterruptedException {
List<String> list = new ArrayList<>();
for (int i = 0; i < 500; i++) {
new Thread(()-> {
synchronized (list){
list.add(Thread.currentThread().getName());
}
}).start();
}
Thread.sleep(2000);
System.out.println(list.size());
}
}