多线程练习-synochronized-notify/wait-lock/condition

子线程循环 10 次，接着主线程循环 100，接着又回到子线程循环 10 次，
* 接着再回到主线程又循环 100，如此循环 50次，请写出程序

注意：

在Eclipse中：run-->Run Configurations-->Common-->Standard input and output （可能不同版本的Eclipse位置会有所不同）

File选择你想要保存的文件（比如：E:\result.txt）。

这样，控制台输出的所有内容都会保存到文本result.txt中

第一次代码：用flag做信号灯，决定该子线程还是主线程跑；

用wait和notify控制交流

package 面试题;

public class Mianshiti {

static boolean flag = false;//真为主线程在跑，假为子线程在跑

/*子线程循环 10 次，接着主线程循环 100，接着又回到子线程循环 10 次，
* 接着再回到主线程又循环 100，如此循环 50次，请写出程*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Mianshiti mianshiti = new Mianshiti();
Mainthread mainthread = new Mainthread(mianshiti);
Subthread subthread = new Subthread(mianshiti);
Thread mainthr = new Thread(mainthread);
Thread subthr = new Thread(subthread);
subthr.start();
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mainthr.start();
}

static class Mainthread implements Runnable{
Object object;

public Mainthread(Object object) {
// TODO Auto-generated constructor stub
this.object = object;
}

@Override
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i < 50; i++) {
synchronized (object) {
if (!flag) {//为假，说明子线程在跑，等他跑完
try {
object.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
for (int j = 0; j < 20; j++) {
System.out.println("mainthread执行第:"+i+"次中：第"+j+"遍");
}
flag=false;//让给子线程跑
object.notify();
}
}
}
}

static class Subthread implements Runnable{

Object object;

public Subthread(Object object) {
// TODO Auto-generated constructor stub
this.object = object;
}

@Override
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i < 50; i++) {
synchronized (object) {
if (flag) {//为真，主线程在跑，等他跑完
try {
object.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
for (int j = 0; j < 10; j++) {
System.out.println("subthread执行第:"+i+"次中：第"+j+"遍");
}
flag = true;//该让给主线程跑
object.notify();
}
}
}
}
}


但是两个类的内容其实一样，所以用一个类装两个方法就可以了；
package 面试题;

public class Mianshiti2 {

static boolean flag = false;

public static void main(String[] args) {
// TODO Auto-generated method stub
Printsign printsign = new Printsign();
Thread subthread = new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i <= 50; i++) {
printsign.subthread(i);
}
}
});
subthread.start();//开始子线程

for (int i = 0; i < 50; i++) {//把main线程作为父线程
printsign.mainthread(i);
}
}

static class Printsign{

public synchronized void subthread(int i) {
if (flag) {
try {
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
for (int j = 0; j < 10; j++) {
System.out.println("subthread执行第:"+i+"次中：第"+j+"遍");
}
flag=true;
this.notify();
}

public synchronized void mainthread(int i) {
if (!flag) {
try {
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
for (int j = 0; j < 20; j++) {
System.out.println("mainthread执行第:"+i+"次中：第"+j+"遍");
}
flag=false;
this.notify();
}
}
}


用condition和lock控制通信：
package 面试题;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/*用condition控制线程通信*/
public class Mianshiti3 {

public static void main(String[] args) {
// TODO Auto-generated method stub
Printsing printsing = new Printsing();
new Thread(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
for (int j = 0; j < 50; j++) {
printsing.subprint(j);
}
}
}).start();

try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

for (int i = 0; i < 50; i++) {
printsing.mainprint(i);
}
}

static class Printsing{
private final Lock lock = new ReentrantLock();
private final Condition condition = lock.newCondition();
boolean flag = false;
public void subprint(int i) {
lock.lock();
try {
if (flag) {
try {
condition.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
for (int j = 0; j < 10; j++) {
System.out.println("subthread执行第:"+i+"次中：第"+j+"遍");
}
flag = true;
condition.signal();
} catch (Exception e) {
// TODO: handle exception
} finally {
lock.unlock();//释放Lock的锁
}
}

public void mainprint(int i) {
lock.lock();
try {
if (!flag) {
try {
condition.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
for (int j = 0; j < 20; j++) {
System.out.println("mainthread执行第:"+i+"次中：第"+j+"遍");
}
flag = false;
condition.signal();
} catch (Exception e) {
// TODO: handle exception
} finally {
lock.unlock();//释放Lock的锁
}
}
}
}