【Java】线程中的wait和notify

线程中的同步问题通常使用的是synchronized块，结合wait和notify方法，今天简单做了一个测试。发现当一个线程锁定了某个临界资源后另一个线程会自动等待，以往自己还认为需要自己写代码让其等待呢。。。

共享资源：

package sm.model;

import org.apache.log4j.Logger;

public class ThreadFuncs {
/**
* Logger for this class
*/
private static final Logger logger = Logger.getLogger(ThreadFuncs.class);

private int shareNum;

public ThreadFuncs(int initShareNum)
{
this.shareNum = initShareNum;
}

public void run1() {
if (shareNum < 10) {
synchronized (this) {
for (; shareNum < 30; shareNum++) {
logger.info("I go to print " + shareNum);
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (shareNum == 10) {
try {
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
}

public void run2() {
/*logger.info("I am in run2 " + shareNum);

while (shareNum == 0) {
try {
logger.info("I am in while " + shareNum);
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}*/

synchronized (this) {
for (; shareNum < 20; shareNum++) {
logger.info("print " + shareNum);
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
this.notify();
}

}
}

线程1：

package sm.examples.threaddemo;

import sm.model.ThreadFuncs;

public class Thread3_1 extends Thread {

private ThreadFuncs funcs;

public Thread3_1(ThreadFuncs funcs)
{
this.funcs = funcs;
}

@Override
public void run() {
funcs.run1();
}

}

线程2：

package sm.examples.threaddemo;

import sm.model.ThreadFuncs;

public class Thread3_2 extends Thread {

private ThreadFuncs funcs;

public Thread3_2(ThreadFuncs funcs)
{
this.funcs = funcs;
}

@Override
public void run() {
funcs.run2();
}

}

测试类：

package sm.test;

import org.junit.Test;

import sm.examples.threaddemo.Thread3_1;
import sm.examples.threaddemo.Thread3_2;
import sm.model.ThreadFuncs;

public class TestThreadWaitNotifyDemo {
@Test
public void test()
{
ThreadFuncs funcs = new ThreadFuncs(0);

Thread t1 = new Thread3_1(funcs);
Thread t2 = new Thread3_2(funcs);

t1.start();
t2.start();

try {
Thread.sleep(100000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}

}