今天做项目，运用线程持续检查我的设备状态时，报了一个异常 java.lang.IllegalThreadStateException，代码如下

private Thread intercomMonitorThread = new Thread(new Runnable() {
public void run() {
boolean hasintercommeeting = true;
while (hasintercommeeting) {
if (intercomList.size() == 0) {
break;
}
for (int i = 0; i < intercomList.size(); i++) {
IntercomMeeting meeting = intercomList.get(i);
PbxAbstractDevice device = pbx.findNumber(meeting.getHandlenum());
PbxAbstractDevice remotedevice = pbx.findNumber(meeting.getUserno());
List<PbxChannel> connlist = device.getClonedConnList();
List<PbxChannel> remoteconnlist = remotedevice.getClonedConnList();
if ((null == connlist || connlist.size() == 0) && (null == remoteconnlist || remoteconnlist.size() == 0)) {
continue;
}

if ((null != connlist && connlist.size() > 0) && (null != remoteconnlist && remoteconnlist.size() > 0)) {
continue;
}
if (null != remoteconnlist && remoteconnlist.size() > 0) {
pbx.hangup(remoteconnlist.get(0).getConnId());
intercomList.remove(meeting);
if (intercomList.size() == 0) {
hasintercommeeting = false;
}
}else {
pbx.hangup(connlist.get(0).getConnId());
intercomList.remove(meeting);
if (intercomList.size() == 0) {
hasintercommeeting = false;
}
}
}

try {
     Thread.sleep(500);
} catch (InterruptedException x) {
Thread.currentThread().interrupt(); 
}
    }
}
});

调用的地方

if (!intercomMonitorThread.isAlive()) {
intercomMonitorThread.start();
}

试着做了修改后，异常没再出现

private Thread intercomMonitorThread;
    Runnable intercommonitor = new Runnable() {
public void run() {
boolean hasintercommeeting = true;
while (hasintercommeeting) {
if (intercomList.size() == 0) {
break;
}
for (int i = 0; i < intercomList.size(); i++) {
IntercomMeeting meeting = intercomList.get(i);
PbxAbstractDevice device = pbx.findNumber(meeting.getHandlenum());
PbxAbstractDevice remotedevice = pbx.findNumber(meeting.getUserno());
List<PbxChannel> connlist = device.getClonedConnList();
List<PbxChannel> remoteconnlist = remotedevice.getClonedConnList();
if ((null == connlist || connlist.size() == 0) && (null == remoteconnlist || remoteconnlist.size() == 0)) {
continue;
}

if ((null != connlist && connlist.size() > 0) && (null != remoteconnlist && remoteconnlist.size() > 0)) {
continue;
}
if (null != remoteconnlist && remoteconnlist.size() > 0) {
pbx.hangup(remoteconnlist.get(0).getConnId());
intercomList.remove(meeting);
if (intercomList.size() == 0) {
hasintercommeeting = false;
}
}else {
pbx.hangup(connlist.get(0).getConnId());
intercomList.remove(meeting);
if (intercomList.size() == 0) {
hasintercommeeting = false;
}
}
}

try {
     Thread.sleep(500);
} catch (InterruptedException x) {
Thread.currentThread().interrupt(); 
intercomMonitorThread = null;
}
    }
Thread.currentThread().interrupt(); 
intercomMonitorThread = null;
}
};

调用的地方

if (null == intercomMonitorThread) {
intercomMonitorThread = new Thread(intercommonitor);
intercomMonitorThread.start();
}