@ConditionalOnProperty注解

@Configuration
@ConditionalOnProperty(prefix = "filter",name = "loginFilter",havingValue = "true")
public class FilterConfig {
    //prefix为配置文件中的前缀,
    //name为配置的名字
    //havingValue是与配置的值对比值,当两个值相同返回true,配置类生效.
    @Bean
    public FilterRegistrationBean getFilterRegistration() {
        FilterRegistrationBean filterRegistration  = new FilterRegistrationBean(new LoginFilter());
        filterRegistration.addUrlPatterns("/*");
        return filterRegistration;
    }
}