正在将requestDestroyed方法编写为servlet本身的一部分，就像下面在功能上等同于将requestDestroyed重写为ServletRequestListener的一部分一样吗？
public class MyServlet implements HttpServlet{
public void init(ServletConfig config) throws ServletException {
//init stuff
}
public void service(ServletRequest req,ServletResponse res)
throws ServletException {
try {
//do some stuff
} finally {
requestDestroyed(request);
}
}
private void requestDestroyed(HttpServletRequest request) {
//some clean up stuff only for this particular servlet
}
}
答案：不，这不是等效的。
有两个选项：
第一个选项：
要覆盖requestDestroyed方法，您需要在自定义侦听器类中实现ServletRequestListener。
例如：
我创建了一个RListener类作为自定义侦听器：
public class RListener implements ServletRequestListener {
@Override
public void requestDestroyed(ServletRequestEvent servletRequestEvent) {
HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequestEvent.getServletRequest();
System.out.println("All resources has been destroyed.")
//some clean up stuff only for this particular servlet
}
@Override
public void requestInitialized(ServletRequestEvent servletRequestEvent) {
HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequestEvent.getServletRequest();
System.out.println("All resources has been initalized.")
//some initialization up stuff only for this particular servlet
}
}
在web.xml中添加<listener>：
<listener>
<listener-class>com.example.RListener</listener-class>
</listener>
第二个选项：
您可以覆盖销毁方法，它是Servlet的生命周期方法：
示例：
public class MyServlet implements HttpServlet{
@Override
public void init(ServletConfig config) throws ServletException {
//init stuff
}
@Override
public void service(ServletRequest request, ServletResponse response)
throws ServletException {
try{
//do some stuff
}finally{
destroy();
}
}
@Override
public void destroy() {
//some clean up stuff only for this particular servlet
}
}