刚开始学java的时候,就最先学习多线程,那时候云里雾里不懂什么叫同步,现在也算是了却了心结.
修饰代码块:
class T implements Runnable {
private static int count;
public T() {
count = 0;
}
public void add() {
synchronized (this) {
for(int i=0;i<5;i++) {
count++;
System.out.println(Thread.currentThread().getName() + "....." + count);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
public void read() {
for(int i=0;i<5;i++) {
System.out.println(Thread.currentThread().getName() + "....." + count);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void run() {
String threadName=Thread.currentThread().getName();
if(threadName.equals("A")) {
add();
}else {
read();
}
}
}
public class SynchronizedDemo {
public static void main(String[] args) {
// TODO Auto-generated method stub
T t = new T();
Thread t1 = new Thread(t, "A");
Thread t2 = new Thread(t, "B");
t1.start();
t2.start();
}
}
修饰一个对象
class Account{
String name;
float amount=0;
public Account(String name) {
this.name=name;
}
public void saveMoney(float amt) {
amount+=amt;
try {
Thread.sleep(200);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void withdrawMoney(float amt) {
amount-=amt;
try {
Thread.sleep(200);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void showMoney(){
System.out.println(Thread.currentThread().getName()+name+"当前余额"+amount+"元");
}
}
class AccountOperator implements Runnable{
private Account acco;
public AccountOperator(String Accountname) {
// TODO Auto-generated constructor stub
this.acco=new Account(Accountname);
}
public void run() {
// TODO Auto-generated method stub
synchronized(acco) {
acco.showMoney();
acco.saveMoney(500);
acco.showMoney();
acco.withdrawMoney(100);
acco.showMoney();
}
}
}
public class SynchronizedDemo2 {
public static void main(String[] args) {
// TODO Auto-generated method stub
AccountOperator accoter=new AccountOperator("Fjy");
Thread t1=new Thread(accoter);
t1.start();
Thread t2=new Thread(accoter);
t2.start();
}
}
想让代码同步运行:
class Syn implements Runnable{
private void a() {
for(int i=0;i<10;i++) {
System.out.println("aaaa");
}
}
private void b() {
for(int i=0;i<10;i++) {
System.out.println("bbbb");
}
}
private String s=new String();
public void run() {
// TODO Auto-generated method stub
synchronized(s) {
a();
b();
}
}
}
public class SynchronizedDemo3 {
public static void main(String[] args) {
// TODO Auto-generated method stub
Syn syn=new Syn();
Thread t1=new Thread(syn);
t1.start();
Thread t2=new Thread(syn);
t2.start();
}
}
