使用Reentrantlock实现可中断线程锁的时候返回：锁对象异常。代码如下
// 客户端及两个Runnable
package com.scl.thread.interrupt;
public class TestLockInterruptibly
{
public static void main(String[] args) throws Exception
{
// 1. 根据lock控制中断
FileHandlerByThreads fileControl = new FileHandlerByThreads();
Thread readthr = new Thread(new ReadThread(fileControl), "reader");
Thread writethr = new Thread(new WriteThread(fileControl), "writer");
// 2. 使用synchronized关键字控制中断线程
// SyncFileHandler sync = new SyncFileHandler();
// Thread readthr = new Thread(new ReadThread(sync), "reader");
// Thread writethr = new Thread(new WriteThread(sync), "writer");
writethr.start();
readthr.start();
long startTime = System.currentTimeMillis();
// 循环判是否有线程获取到了读锁断
while (!fileControl.isGetReadLock())
{
long endTime = System.currentTimeMillis();
// 如果4秒后读线程仍然没有等到读锁，离开等待
if (endTime - startTime > 4000)
{
readthr.interrupt();
System.out.println("4 seconds have passed,try to interrupt reader Thread");
break;
}
}
}
}
class ReadThread implements Runnable
{
private IFileHandler fileControl;
public ReadThread(IFileHandler fileControl)
{
this.fileControl = fileControl;
}
@Override
public void run()
{
try
{
fileControl.read();
}
catch (InterruptedException e)
{
// e.printStackTrace();
// 测试单纯使用synchronized关键字控制线程中断
System.out.println("reader thread end");
fileControl.formatFile();
}
}
}
class WriteThread implements Runnable
{
private IFileHandler fileControl;
public WriteThread(IFileHandler fileControl)
{
this.fileControl = fileControl;
}
@Override
public void run()
{
fileControl.write();
}
}
//线程逻辑代码
package com.scl.thread.interrupt;
import java.util.concurrent.locks.ReentrantLock;
public class FileHandlerByThreads implements IFileHandler
{
private volatile boolean isGetReadLock = false;
private ReentrantLock lock = new ReentrantLock();
public boolean isGetReadLock()
{
return isGetReadLock;
}
public void read()
{
try
{
// 等待20毫秒再进行后续操作，防止主线程操作过快
Thread.sleep(50);
// 使用reentrantlock
lock.lockInterruptibly();
System.out.println(Thread.currentThread().getName() + " start");
isGetReadLock = true;
}
catch (InterruptedException e)
{
// e.printStackTrace();
System.out.println("reader Thread leave the file and going to format the file");
}
finally
{
lock.unlock();
}
}
// 模拟运行时间比较久的写操作
public void write()
{
try
{
// 1.使用lock实现写锁定
// 等待20毫秒再进行后续操作，防止主线程操作过快
Thread.sleep(20);
lock.lock();
System.out.println(Thread.currentThread().getName() + " start");
long startTime = System.currentTimeMillis();
// 模拟一个耗时较长的操作
for (;;)
{
if (System.currentTimeMillis() - startTime > Integer.MAX_VALUE)
{
break;
}
}
System.out.println("Writer has writered down everything! bravo");
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
lock.unlock();
}
}
public void formatFile()
{
System.out.println("begin to format the file");
// format the file
}
}
在对比其他人的代码时发现引起锁对象异常是由 FileHandlerByThreads对象内read方法里面的lock.lockInterruptibly();位置引起，把该代码提到try代码块前面则代码不返回java.lang.IllegalMonitorStateException异常。请问这是怎么回事？
