我想使用 slf4j 而不是 log4j。我在 pom.xml 中添加了以下依赖项(我对 slf4j 使用 1.7.25,对 log4j2 使用 2.10.0):
<dependencies>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>${log4j.version}</version>
</dependency>
</dependencies>
一切都构建得很好,没有编译错误或缺乏依赖项,但我未能在类中指定负责 Logger 初始化的配置 (log4j2.xml) 文件。在这种情况下,它总是打印相同的警告
log4j:WARN No appenders could be found for logger (com.mypackage.etc).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
我搜索了提供配置文件的正确方法,最终得到以下结果:
LoggerContext context = (org.apache.logging.log4j.core.LoggerContext) LogManager.getContext(false);
File file = new File("path/to/a/different/log4j2.xml");
context.setConfigLocation(file.toURI());
问题是,在我的例子中,LogManager.getContext(false) 将始终返回 Slf4JLoggerContext 的实例(考虑到我使用 slf4j 作为记录器的外观),并且初始化将失败并出现 ClassCastException。我尝试存储 Slf4JLoggerContext 的实例,但它没有为上下文提供设置器。我也未能找到从 log4j 检索 LoggerContext 的方法。
有没有办法向 slf4j 提供配置文件(log4j2.xml)以便查看所有附加程序和记录器?
Update考虑这是我的配置文件(我替换了原始包和附加程序名称):
<?xml version="1.0" encoding="UTF-8"?>
<Configuration>
<Properties>
<Property name="def.files.backup.count">10</Property>
<Property name="log.file.path">${oo.home}/var/logs</Property>
<Property name="def.file.max.size">10MB</Property>
<Property name="log.level">WARN</Property>
</Properties>
<ThresholdFilter/>
<Appenders>
<RollingFile name="Appender1" fileName="${log.file.path}/file1.log" maxFileSize="${def.file.max.size}"
maxBackupIndex="${def.files.backup.count}">
<PatternLayout>org.apache.log4j.PatternLayout</PatternLayout>
<Policies>
<SizeBasedTriggeringPolicy size="10MB"/>
</Policies>
</RollingFile>
<RollingFile name="Appender2" fileName="${log.file.path}/file2.log"
maxFileSize="${def.file.max.size}"
maxBackupIndex="${def.files.backup.count}">
<PatternLayout>org.apache.log4j.PatternLayout</PatternLayout>
<Policies>
<SizeBasedTriggeringPolicy size="10MB"/>
</Policies>
</RollingFile>
<RollingFile name="Appender3" fileName="${log.file.path}/file3.log"
maxFileSize="${def.file.max.size}"
maxBackupIndex="${def.files.backup.count}">
<PatternLayout>org.apache.log4j.PatternLayout</PatternLayout>
<Policies>
<SizeBasedTriggeringPolicy size="10MB"/>
</Policies>
</RollingFile>
</Appenders>
<Loggers>
<AsyncLogger name="com.package1.oo" level="${log.level}" additivity="false">
<AppenderRef ref="Appender1"/>
</AsyncLogger>
<AsyncLogger name="io.package2" level="${log.level}" additivity="false">
<AppenderRef ref="Appender2"/>
</AsyncLogger>
<AsyncLogger name="com.package3.package3" level="${log.level}" additivity="false">
<AppenderRef ref="Appender3"/>
</AsyncLogger>
<AsyncLogger name="org.package4" level="${log.level}">
</AsyncLogger>
<AsyncLogger name="com.package5.Class1" level="${log.level}">
</AsyncLogger>
<AsyncRoot level="${log.level}">
<AppenderRef ref="Appender1"/>
<AppenderRef ref="Appender2"/>
<AppenderRef ref="Appender3"/>
</AsyncRoot>
</Loggers>
</Configuration>