java - How to turn off logging for one URL log4j

Question

I have project on old version of dropwizrd (0.9.3 where is no any log filter(https://www.dropwizard.io/en/release-0.9.x/manual/core.html#logging)) and I want to disable log for one url.

I try to use it:

package com.pack.service.services;

import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.filter.Filter;
import ch.qos.logback.core.spi.FilterReply;


public class LogFilter extends Filter<ILoggingEvent> {

  final static String SPAM_URL = "spam";

  @Override
  public FilterReply decide(ILoggingEvent event) {
    if (!event.getMessage().contains(SPAM_URL)) {
      return FilterReply.ACCEPT;
    } else {
      return FilterReply.NEUTRAL;
    }
  }
}

And in folder resources in log4j2.xml file I added it:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="ERROR" >
    <Appenders>

        <Filter class="com.pack.service.services.LogFilter"/>

        <Console name="console" target="SYSTEM_OUT">
            <PatternLayout pattern="[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n" />
        </Console>
    </Appenders>
    <Loggers>
        <Root level="error" additivity="false">
            <AppenderRef ref="console" />
        </Root>
    </Loggers>
</Configuration>

But I got the error:

2021-04-01 16:26:33,473 main ERROR Appenders contains an invalid element or attribute "filter"

Answer 1

You created a Filter for Logback and tried to use it in Log4j 2. They are completely different frameworks. You can look at the MarkerFilter as an example of how to create a Filter for Log4j 2.

I should also point out that your configuration of the filter would be wrong. Log4j uses a Plugin system so you never specify class names in the configuration.

Having said that, you don't need to create your own filter. Just use Log4j's RegexFilter. Or if you want to duplicate your code you could use the ScriptFilter and write the equivalent code in any Scripting language that supports JSR 223 such as Groovy.