public static ServletCounter getInstance() { if (instance==null) { synchronized(lock) { if (instance == null) { instance = new ServletCounter(); } } } return instance; }
public synchronized int getCounter() { return counter; } public synchronized int setCounter(int c) { counter = c; return counter; } public synchronized int incCounter() { return (++counter); }
public synchronized int decCounter() { return (--counter); } } 然后在每个Servelet的init()方法中加入: ServletCounter.getInstance().incCounter(); 再在每个Servelet的destroy()方法中加入:ServletCounter.getInstance().decCounter(); 不就行了吗。
看到里面servlet的配置
但是有的servlet配了,不一定被启动了阿
private static Object lock = new Object();
private static ServletCounter instance = null;
private int counter;
private ServletCounter() {
counter = 0;
}
public static ServletCounter getInstance() {
if (instance==null) {
synchronized(lock) {
if (instance == null) {
instance = new ServletCounter();
}
}
}
return instance;
}
public synchronized int getCounter() {
return counter;
} public synchronized int setCounter(int c) {
counter = c;
return counter;
} public synchronized int incCounter() {
return (++counter);
}
public synchronized int decCounter() {
return (--counter);
}
}
然后在每个Servelet的init()方法中加入: ServletCounter.getInstance().incCounter();
再在每个Servelet的destroy()方法中加入:ServletCounter.getInstance().decCounter();
不就行了吗。
现在想想,jsp 最终也会变成 servlet, 这些怎么监控?