线程lock condition使用

Question

下面是具体例子，一直抛错，搞不懂应该怎么用了；求修改求思想
package com.sixth.exam;import java.util.concurrent.locks.*;public class T3{
public static void main(String[] args)
{

ReentrantLock lock=new ReentrantLock();
PrintThread pt=new PrintThread(lock);
Thread t=new Thread(pt);
t.start();
}
}
class PrintThread implements Runnable
{

ReentrantLock lock;
Condition condition;
PrintThread1 pt1;
Thread t1;
public PrintThread(ReentrantLock lock)
{ 
this.lock=lock;
condition=lock.newCondition();
pt1=new PrintThread1(lock);
t1=new Thread(pt1);
}
public void run()
{
t1.start();
for(int i=3;i>=0;i--)
{
System.out.println(i+"....");
if(i==1)
{
System.out.println("起床啦");
condition.signalAll();
}
}

}
}
class PrintThread1 implements Runnable
{
ReentrantLock lock;
Condition condition;
public PrintThread1(ReentrantLock lock)
{ 
this.lock=lock;
condition=lock.newCondition();
}
public void run()
{
try {
lock.newCondition().await();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("复活了~");
}
}

Answer 1

import java.util.concurrent.locks.*;public class T3 {
public static void main(String[] args) { ReentrantLock lock = new ReentrantLock();
PrintThread pt = new PrintThread(lock);
Thread t = new Thread(pt);
t.start();
}
}class PrintThread implements Runnable { ReentrantLock lock;
Condition condition;
PrintThread1 pt1;
Thread t1; public PrintThread(ReentrantLock lock) {
this.lock = lock;
condition = lock.newCondition();
pt1 = new PrintThread1(lock, condition);
t1 = new Thread(pt1);
} public void run() {
t1.start();
for (int i = 3; i >= 0; i--) {
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(i + "....");
if (i == 1) {
System.out.println("起床啦");
lock.lock();
try {
condition.signal();
} finally {
lock.unlock();
}
}
} }
}class PrintThread1 implements Runnable {
ReentrantLock lock;
Condition condition; public PrintThread1(ReentrantLock lock, Condition condition) {
this.lock = lock;
this.condition = condition;
} public void run() {
lock.lock();
try {
condition.await();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
System.out.println("复活了~");
}
}

Answer 2

你就把lock.lock()当做synchronized(object);
但是记得必须要 lock.unlock();
不是十分有把握的情况下，尽量用synchronized，简单，易懂。性能上的差距只是代码级的。

Answer 3

怎么设置加锁的位置？
我在不同的代码块加锁Console输出的不同