springboot#interceptor

public class My1Interceptor  extends HandlerInterceptorAdapter  {
	
	/**
	 * 请求在处理之前时，调用这个方法
	 */
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
			throws Exception {
		System.err.println("==>preHandle........................");
		// 因为是模拟，所以token就加在url后面
		String token = request.getParameter("token");
		if(token !=null && token.equals("true")) {
			System.err.println("token is valid,procedue.");
			return super.preHandle(request, response, handler);
		}else {
			System.err.println("token is invalid,redirect to login page.");
			 String url = request.getContextPath() + "/login";
			 System.err.println(url);
		     response.sendRedirect(url);
			return false;
		}
		
	}
	
	/**
	 * 请求在处理之后，调用这个方法
	 */
	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
			ModelAndView modelAndView) throws Exception {
		System.err.println("==>postHandle........................");
		super.postHandle(request, response, handler, modelAndView);
	}
	
	/**
	 * 请求在完成postHandle处理之后，调用这个方法
	 * 如果请求在preHandle时被return false,这个方法不会执行
	 */
	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
			throws Exception {
		System.err.println("==>afterCompletion........................");
		super.afterCompletion(request, response, handler, ex);
	}
}

@Configuration
public class MyWebMvcConfig extends WebMvcConfigurerAdapter {
	@Override
	public void addInterceptors(InterceptorRegistry registry) {
		registry.addInterceptor(new My1Interceptor()).addPathPatterns("/do*");
		// 这里还可以注册别的拦截器
		// 这里还可以注册别的拦截器
		// 这里还可以注册别的拦截器
		super.addInterceptors(registry);
	}
}