cannot resolve symbol的问题
小弟初学java,运行一下别人写好的代码。是一个打字的applet。代码如下:
public class TypeTrainApplet extends JApplet {
…
private class GenerateDropThread extends Thread {
Random random = new Random(); //随机数
public void run() {
try {
while (statusCode != 0) { //产生下落线程
synchronized (canvas) {
while (statusCode == 2) {
canvas.wait();
}
}
DropCharThread dropCharThread = new DropCharThread(
getRandomChar(),
random.nextInt(columnCount) + 1);
dropCharThread.start();
Thread.sleep(generateInterval);
}
} catch (InterruptedException ex) {
}
}
可是总提示Random random = new Random(); 这一行是“cannot resolve symbol”。这是为什么啊?