How to filter a specific exception from Log4j?

Question

I'm implementing some new features of Java 8 on my desktop app and Hibernate 3.6 seems to doesn't like it.

I added to an Interface a "default method", since then Hibernate it throwing:

2014-10-02 14:01:25,538 WARN entity.PojoEntityTuplizer  - could not create proxy factory for:modelo.ChequeTercero
org.hibernate.HibernateException: Javassist Enhancement failed: modelo.ChequeTercero
at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.getProxyFactory(JavassistLazyInitializer.java:169)
at org.hibernate.proxy.pojo.javassist.JavassistProxyFactory.postInstantiate(JavassistProxyFactory.java:65)
Caused by: java.lang.VerifyError: (class: modelo/ChequeTercero_$$_javassist_45, method: _d21getNumeroValor signature: ()Ljava/lang/String;) Illegal use of nonvirtual function call

for EACH class that implement the interface multiplied for EACH default method in the interface.

As this log is a Level.WARN, it is generating biiiiiiiiiig log file on the users every time they open the application.

I tried to make some logger filters but is not working:

<filter class="org.hibernate.proxy.pojo.BasicLazyInitializer">
<param name="LevelMin" value="FATAL" />
<param name="LevelMax" value="FATAL" />
    </filter>
<filter class="org.apache.log4j.filter.ExpressionFilter">
        <param name="expression" value="EXCEPTION ~= org.hibernate.proxy.pojo.BasicLazyInitializer"/>
        <param name="acceptOnMatch" value="false"/>
    </filter>
    <filter class="org.apache.log4j.varia.StringMatchFilter">
        <param name="StringToMatch" value="org.hibernate.HibernateException: Javassist Enhancement failed"/>
        <param name="AcceptOnMatch" value="false" />
    </filter>
    <!--<filter class="org.apache.log4j.varia.DenyAllFilter"/> -->

What am I doing wrong? Also if I uncomment DenyAllFilter no log appears anymore.

Answer 1

Using log4j 1.2 I am able to filter out specific exceptions, using an ExpressionFilter in the Appender.

<appender name="LOGFILE" class="com.me.RollingFileAppender">
    <param name="File" value="..." />
    ...
    <layout .../>
    <!-- Exclude expected exceptions -->
    <filter class="org.apache.log4j.filter.ExpressionFilter">
        <param name="Expression" value="EXCEPTION ~= 'String found in the exception message'"/>
        <param name="AcceptOnMatch" value="false"/>
    </filter>
</appender>

See http://blog.trifork.com/2011/08/23/filtering-specific-exceptions-when-using-log4j/

Answer 2

I have found the solution - RegexFilter.

Here is the related Log4j 2.x configuration, that allows me to exclude specific messages both from log file and console appenders.

<Appenders>
    <Console name="console" target="System.out">
        <RegexFilter regex=".*(Javassist Enhancement failed|could not create proxy factory for).*" onMatch="DENY" onMismatch="ACCEPT"/>
        <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss} %-2p %c{1.} %x - %m%n"/> 
    </Console>
    <File name="logfile" filename="./app.log" append="true">
        <!--Evita cargar en el log el error que tira hibernate por Java 8 (default method en Interfaces)-->
        <RegexFilter regex=".*(Javassist Enhancement failed|could not create proxy factory for).*" onMatch="DENY" onMismatch="ACCEPT"/>
        <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss} [%t] %-5p %c{-1} %X{userName} - %m%n"/> 
    </File>
</Appenders>