Question

我正在开发一个Spring启动应用程序，我想通过我的slf4j日志系统将Tomcat的访问日志路由到远程系统日志。

因为它是Spring，所以我想避免触及tomcat的server.xml文件。

我的AccessLogValve非常简单：

import java.io.CharArrayWriter;
import org.apache.catalina.valves.AccessLogValve;

public class Log4JAccessLogValve extends AccessLogValve {
    @Override
    public void log(CharArrayWriter message) {
        log.info(message.toString());
    }
}

我希望可以使用这样的东西将它连接到Tomcat：

@Component
public class LogConfig {

    @Autowired
    private ServletContext servletContext;

    @PostConstruct
    public void setAccessLogValve() {
        ((ApplicationContextFacade)servletContext).addValve(new Log4JAccessLogValve());
    }

}

除了addValve（）方法不存在...

所以......任何人都知道如何在我的AccessLogValve中挂钩？

我也接受完全不同的建议来获取远程系统日志中的访问日志，但我们正在制作数十种微服务，因此它必须是一种非常标准化的方法，对于每个微服务都很容易实现。

Answer 1

使用EmbeddedServletContainerCustomizer界面。为嵌入式tomcat添加自定义阀门。

例如

@Configuration
public class WebConfig extends WebMvcConfigurerAdapter implements EmbeddedServletContainerCustomizer {

   @Override
   public void customize(ConfigurableEmbeddedServletContainer container) {
       if (container instanceof TomcatEmbeddedServletContainerFactory) {
           TomcatEmbeddedServletContainerFactory factory = (TomcatEmbeddedServletContainerFactory) container;
           AccessLogValve accessLogValve = new Log4JAccessLogValve();
           accessLogValve.setDirectory("/var/log/access_log");
           accessLogValve.setPattern("%h %u %t &quot;%r&quot; %s %b - %T");
           accessLogValve.setSuffix(".log");
           factory.addContextValves(accessLogValve);
       } else {
           logger.error("WARNING! this customizer does not support a custom configured container");
       }
   }

}

Answer 2

将这些答案组合成适用于springboot 2.0的内容

import org.apache.catalina.valves.AbstractAccessLogValve;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.stereotype.Component;

import java.io.CharArrayWriter;

/**
 * see https://www.baeldung.com/embeddedservletcontainercustomizer-configurableembeddedservletcontainer-spring-boot
 * 
*/
@Component
@Slf4j
public class CustomizeEmbeddedTomcatContainer implements WebServerFactoryCustomizer<TomcatServletWebServerFactory> {

    @Override
    public void customize(TomcatServletWebServerFactory factory) {

        log.info("configuring embedded Tomcat");
        TomcatSlf4jAccessValve accessLogValve = new TomcatSlf4jAccessValve();
        accessLogValve.setEnabled(true);

        /**
         * for pattern format see https://tomcat.apache.org/tomcat-7.0-doc/api/org/apache/catalina/valves/AccessLogValve.html
         */
        accessLogValve.setPattern("request: method=%m uri=\"%U\" response: statuscode=%s bytes=%b duration=%D(ms) client: remoteip=%a user=%u useragent=\"%{User-Agent}i\"");

        factory.addContextValves(accessLogValve);
    }


    public static class TomcatSlf4jAccessValve extends AbstractAccessLogValve {

        Logger httpAccessLogLogger = LoggerFactory.getLogger("http_access_log");

        @Override
        protected void log(CharArrayWriter message) {
            httpAccessLogLogger.info(message.toString());
        }

    }
}

Answer 3

此外，我建议使用AbstractAccessLogValve而不是AccessLogValve扩展Log4JAccessLogValve。它不会初始化AccessLogValve的文件访问日志文件相关功能

例如：

import java.io.CharArrayWriter;
import org.apache.catalina.valves.AbstractAccessLogValve;

public class Log4JAccessLogValve extends AbstractAccessLogValve {

    @Override
    protected void log(CharArrayWriter message) {
        LOGGER.info(message.toString());
    }

}

如何以编程方式将AccessLogValve添加到Tomcat？

3 个答案: