过滤器
Filter | 过滤器
过滤器配置
现在我们通过过滤器来实现记录请求执行时间的功能,其实现如下:
public class LogCostFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
long start = System.currentTimeMillis();
filterChain.doFilter(servletRequest,servletResponse);
System.out.println("Execute cost="+(System.currentTimeMillis()-start));
}
@Override
public void destroy() {
}
}
这段代码的逻辑比较简单,就是在方法执行前先记录时间戳,然后通过过滤器链完成请求的执行,在返回结果之间计算执行的时间。这里需要主要,这个类必须继承
@Configuration
public class FilterConfig {
@Bean
public FilterRegistrationBean registFilter() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new LogCostFilter());
registration.addUrlPatterns("/*");
registration.setName("LogCostFilter");
registration.setOrder(1);
return registration;
}
}
除了通过
@WebFilter(urlPatterns = "/*", filterName = "logFilter2")
public class LogCostFilter2 implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
long start = System.currentTimeMillis();
filterChain.doFilter(servletRequest, servletResponse);
System.out.println("LogFilter2 Execute cost=" + (System.currentTimeMillis() - start));
}
@Override
public void destroy() {
}
}
这里直接用
@SpringBootApplication
@MapperScan("com.pandy.blog.dao")
@ServletComponentScan("com.pandy.blog.filters")
public class Application {
public static void main(String[] args) throws Exception {
SpringApplication.run(Application.class, args);
}
}