簡介
SpringBoot可以簡化開發流程，但是在其中如何使用傳統的J2EE servlet/listener/filter呢
@Bean配置
在Configuration類中加入filter和servlet的registration
@Bean
public FilterRegistrationBean registFilter() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new Filter(){
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
System.out.println("in filter");
chain.doFilter(request, response);
}
@Override
public void destroy() {
}
});
registration.addUrlPatterns("/*");
registration.setOrder(1);
return registration;
}
@SuppressWarnings("serial")
@Bean
public ServletRegistrationBean registServlet() {
ServletRegistrationBean servletRegist=new ServletRegistrationBean();
servletRegist.setServlet(new HttpServlet (){
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.getWriter().write("inside servlet");
}
});
servletRegist.addUrlMappings("/registedServlet");
return servletRegist;
}
運行項目就可以訪問servlet和filter了，在registrationBean中可以配置路徑和實例。
使用Servlet3.0
如果使用Servlet3.0的話，可以在Configuration類上加@ServletComponentScan("類路徑")
並開發對應的filter、listener、servlet
@WebFilter
public class CustFilter implements Filter{
@Override
public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
System.out.println("in filter2");
chain.doFilter(request, response);
}
@Override
public void destroy() {
// TODO Auto-generated method stub
}
}
@WebListener
public class CustListener implements HttpSessionListener {
@Override
public void sessionCreated(HttpSessionEvent se) {
System.out.println("session created");
}
@Override
public void sessionDestroyed(HttpSessionEvent se) {
// TODO Auto-generated method stub
}
}
@WebServlet(urlPatterns={"/cust"})
public class CustServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.getSession().setAttribute("a", "1");
resp.getWriter().write("cust servlet");
}
}
在訪問localhost:8080/cust時，對應的filter、listener、servlet都會被訪問到