相关疑难解决方法(0)

假设我正在运行一项服务,用户可以提交正则表达式来搜索大量数据.如果用户提交一个非常慢的正则表达式(即,需要几分钟才能返回Matcher.find()),我想要一种方法来取消该匹配.我能想到这样做的唯一方法是让另一个线程监视匹配的持续时间,并在必要时使用Thread.stop()取消它.

成员变量:

long REGEX_TIMEOUT = 30000L;
Object lock = new Object();
boolean finished = false;
Thread matcherThread;

匹配线程:

try {
    matcherThread = Thread.currentThread();

    // imagine code to start monitor thread is here

    try {
        matched = matcher.find();
    } finally {
        synchronized (lock) {
            finished = true;
            lock.notifyAll();
        }
    }
} catch (ThreadDeath td) {
    // send angry message to client
    // handle error without rethrowing td
}

监控线程:

synchronized (lock) {
    while (! finished) {
        try {
            lock.wait(REGEX_TIMEOUT);

            if (! …