我正试图在Log4J2中实现和配置一个基于ThresholdFilter的自定义Filter,但我打算做得更多。我看到了关于自定义appenders的主题,它们遵循相同的插件注释语法,但还没有找到关于自定义fitlers的主题。
MyCustomFilter.java(基于ThresholdFilter)
@Plugin(name = "MyCustomFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE, printObject = true)
public class MyCustomFilter extends AbstractFilter {
private static final long serialVersionUID = 1L;
private final Level level;
private MyCustomFilter(final Level level, final Result onMatch, final Result onMismatch) {
super(onMatch, onMismatch);
this.level = level;
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg, final Object... params) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg, final Throwable t) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg, final Throwable t) {
return filter(level);
}
@Override
public Result filter(final LogEvent event) {
return filter(event.getLevel());
}
private Result filter(final Level level) {
return level.isMoreSpecificThan(this.level) ? onMatch : onMismatch;
}
@Override
public String toString() {
return level.toString();
}
/**
* Create a MyCustomFilter.
*
* @param level
* The log Level.
* @param match
* The action to take on a match.
* @param mismatch
* The action to take on a mismatch.
* @return The created MyCustomFilter.
*/
@PluginFactory
public static MyCustomFilter createFilter(@PluginAttribute("level") final Level level, @PluginAttribute("onMatch") final Result match,
@PluginAttribute("onMismatch") final Result mismatch) {
final Level actualLevel = level == null ? Level.ERROR : level;
final Result onMatch = match == null ? Result.NEUTRAL : match;
final Result onMismatch = mismatch == null ? Result.DENY : mismatch;
return new MyCustomFilter(actualLevel, onMatch, onMismatch);
}
}
log4j2.xml
<?xml version="1.0" encoding="UTF-8"?>
<Configuration>
<MyCustomFilter level="fatal" />
<Appenders>
<Console name="STDOUT" target="SYSTEM_OUT">
<PatternLayout pattern="%d %-5p [%c{5}.%M():%L] %m%n" />
</Console>
</Appenders>
<Loggers>
<Logger name="com.me.test.logger" level="info" additivity="false">
<AppenderRef ref="STDOUT" />
</Logger>
<!-- Root Logger -->
<Root level="warn">
<AppenderRef ref="STDOUT" />
</Root>
</Loggers>
</Configuration>
LoggingRunner.java
public class LoggingRunner {
public static void main(String[] args) {
Logger logger = LogManager.getLogger("com.me.test.logger");
logger.fatal("Fatal");
logger.error("Error");
logger.debug("Debug");
logger.info("Info");
System.out.println("end it");
}
}
配置语法似乎与Apache文档中的语法相匹配,并模仿ThresholdFilter(一个有效的、提供的过滤器)。如果我如图所示将其作为上下文级别的过滤器,我不会看到任何错误,但过滤器不会被调用或应用。
如果我在Appender中移动我的自定义过滤器标签(这在开箱即用的过滤器中是可能的,我会得到2015-03-24 16:20:11,713 ERROR AppenderRef contains an invalid element or attribute "MyCustomFilter"
.
基于ApacheLog4J2文档和log42j核心源代码中的示例,我认为这会奏效。
我做错了什么?
您能显示配置的第一行<Configuration>
元素吗?
您可以指定<Configuration status="trace">
以使log4j的内部日志记录显示在控制台上,这可能有助于解决问题。
也许log4j找不到你的插件。
编译插件时,会创建一个序列化的插件列表文件。此文件包含插件的名称和二进制格式的类名。如果这个文件包含在包含插件类的jar中,log4j可以找到你的插件。另一种帮助log4j找到插件的方法是在配置文件中指定packages
属性:
<Configuration status="trace" packages="com.me.mycustomfilterpackage"> ...
有关更多详细信息,请参阅关于PluginManager如何查找插件的手册页。