java 同步异常 报java.lang.IllegalMonitorStateException的异常，求大神帮忙解析。

package demo;

public class Demo {
public static void main(String[] args) {
Q q = new Q();
new Producer(q,lock);
new Coustomer(q,lock);

}
}

class Q {
int i;
boolean flag = false;

public int get() {
return i;
}

public void put(int i) {
this.i = i;
}
}

class Producer implements Runnable {
Thread t;
Q q;
int n = 0;

public Producer(Q q,Object o) {
this.q = q;
lock = o;
t = new Thread(this, "producer");
t.start();
}

@Override
public void run() {
while (true) {
synchronized (q) {
if (q.flag) {
try {
System.out.println("coustomer wait....");
wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

q.put(10);
System.out.println(Thread.currentThread().getName() + ":" + q.i);
q.flag = true;
notify();

}
}
}
}

class Coustomer implements Runnable {
Thread t;
Q q;

public Coustomer(Q q,Object o) {
lock = o;
this.q = q;
t = new Thread(this, "customer");
t.start();
}

public void run() {

while (true) {
synchronized (q) {

if (!q.flag) {
try {
System.out.println("coustomer wait....");
wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

q.flag = false;
System.out.println(Thread.currentThread().getName() + ":" + q.i);
notify();
}
}
}
}

去掉notify();

因为当前线程不含有当前对象的锁资源的时候，调用obj.notify()方法

会出现异常，你试一下。

没有这个方法，看看你的源码，是不是定义有问题，isloopback() z ,后面怎么会有一个z。。。。。。。