我有这样的logback配置：
<configuration>
<appender name="SYSLOG-DEFAULT-APPENDER" class="com.papertrailapp.logback.Syslog4jAppender">
<layout class="ch.qos.logback.classic.PatternLayout">
<pattern>IRC: %m%n%xEx</pattern>
</layout>
<syslogConfig class="org.productivity.java.syslog4j.impl.net.tcp.TCPNetSyslogConfig">
<host>127.0.0.1</host>
<port>514</port>
<ident>guacamole_client</ident>
<facility>local0</facility>
<maxMessageLength>128000</maxMessageLength>
</syslogConfig>
</appender>
<!-- Log at INFO level -->
<root level="info">
<appender-ref ref="SYSLOG-DEFAULT-APPENDER" />
</root>
</configuration>
但是当我启动应用程序时有时（！）我看到堆栈跟踪错误：
11:10:40,478 |-INFO in ch.qos.logback.core.model.processor.ImplicitModelHandler - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
11:10:40,564 |-INFO in ch.qos.logback.core.model.processor.AppenderModelHandler - Processing appender named [SYSLOG-DEFAULT-APPENDER]
11:10:40,564 |-INFO in ch.qos.logback.core.model.processor.AppenderModelHandler - About to instantiate appender of type [com.papertrailapp.logback.Syslog4jAppender]
11:10:40,586 |-WARN in ch.qos.logback.core.joran.util.beans.BeanDescriptionFactory@1c5d2f51 - Class 'org.productivity.java.syslog4j.impl.net.tcp.TCPNetSyslogConfig' contains multiple setters for the same property 'delimiterSequence'.
11:10:40,586 |-WARN in ch.qos.logback.core.joran.util.beans.BeanDescriptionFactory@1c5d2f51 - Class 'org.productivity.java.syslog4j.impl.net.tcp.TCPNetSyslogConfig' contains multiple setters for the same property 'facility'.
11:10:40,586 |-WARN in ch.qos.logback.core.joran.util.beans.BeanDescriptionFactory@1c5d2f51 - Class 'org.productivity.java.syslog4j.impl.net.tcp.TCPNetSyslogConfig' contains multiple setters for the same property 'splitMessageEndText'.
11:10:40,586 |-WARN in ch.qos.logback.core.joran.util.beans.BeanDescriptionFactory@1c5d2f51 - Class 'org.productivity.java.syslog4j.impl.net.tcp.TCPNetSyslogConfig' contains multiple setters for the same property 'splitMessageBeginText'.
11:10:40,587 |-WARN in ch.qos.logback.core.joran.util.PropertySetter@6a7d70b0 - Failed to set property [facility] to value "local0". ch.qos.logback.core.util.PropertySetterException: Conversion to type [int] failed.
at ch.qos.logback.core.util.PropertySetterException: Conversion to type [int] failed.
at at ch.qos.logback.core.joran.util.PropertySetter.setProperty(PropertySetter.java:119)
at at ch.qos.logback.core.joran.util.PropertySetter.setProperty(PropertySetter.java:96)
at at ch.qos.logback.core.model.processor.ImplicitModelHandler.doBasicProperty(ImplicitModelHandler.java:111)
at at ch.qos.logback.core.model.processor.ImplicitModelHandler.handle(ImplicitModelHandler.java:86)
at at ch.qos.logback.core.model.processor.DefaultProcessor.secondPhaseTraverse(DefaultProcessor.java:241)
at at ch.qos.logback.core.model.processor.DefaultProcessor.secondPhaseTraverse(DefaultProcessor.java:253)
at at ch.qos.logback.core.model.processor.DefaultProcessor.secondPhaseTraverse(DefaultProcessor.java:253)
at at ch.qos.logback.core.model.processor.DefaultProcessor.secondPhaseTraverse(DefaultProcessor.java:253)
at at ch.qos.logback.core.model.processor.DefaultProcessor.traversalLoop(DefaultProcessor.java:90)
at at ch.qos.logback.core.model.processor.DefaultProcessor.process(DefaultProcessor.java:106)
at at ch.qos.logback.core.joran.GenericXMLConfigurator.processModel(GenericXMLConfigurator.java:208)
at at ch.qos.logback.core.joran.GenericXMLConfigurator.doConfigure(GenericXMLConfigurator.java:170)
at at ch.qos.logback.core.joran.GenericXMLConfigurator.doConfigure(GenericXMLConfigurator.java:122)
at at ch.qos.logback.core.joran.GenericXMLConfigurator.doConfigure(GenericXMLConfigurator.java:65)
at at ch.qos.logback.classic.util.DefaultJoranConfigurator.configureByResource(DefaultJoranConfigurator.java:68)
at at ch.qos.logback.classic.util.DefaultJoranConfigurator.configure(DefaultJoranConfigurator.java:35)
at at ch.qos.logback.classic.util.ContextInitializer.invokeConfigure(ContextInitializer.java:128)
at at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:103)
at at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:66)
at at ch.qos.logback.classic.spi.LogbackServiceProvider.initializeLoggerContext(LogbackServiceProvider.java:52)
at at ch.qos.logback.classic.spi.LogbackServiceProvider.initialize(LogbackServiceProvider.java:41)
at at org.slf4j.LoggerFactory.bind(LoggerFactory.java:196)
at at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:183)
at at org.slf4j.LoggerFactory.getProvider(LoggerFactory.java:486)
at at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:472)
at at ch.qos.logback.classic.util.StatusViaSLF4JLoggerFactory.addStatus(StatusViaSLF4JLoggerFactory.java:34)
at at ch.qos.logback.classic.util.StatusViaSLF4JLoggerFactory.addInfo(StatusViaSLF4JLoggerFactory.java:22)
at at ch.qos.logback.classic.servlet.LogbackServletContainerInitializer.onStartup(LogbackServletContainerInitializer.java:33)
at at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4438)
at at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:171)
at at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:599)
at at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:571)
at at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:603)
at at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1751)
at at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:264)
at at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:814)
at at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:802)
at at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:453)
at at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:407)
at at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:264)
at at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:814)
at at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:802)
at at java.management/com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:472)
at at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1472)
at at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1310)
at at java.base/java.security.AccessController.doPrivileged(AccessController.java:712)
at at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1412)
at at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
at at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at at java.rmi/sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:360)
at at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:200)
at at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:197)
at at java.base/java.security.AccessController.doPrivileged(AccessController.java:712)
at at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:587)
at at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
at at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:705)
at at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:704)
at at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.NumberFormatException: For input string: "local0"
at at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:67)
at at java.base/java.lang.Integer.parseInt(Integer.java:668)
at at java.base/java.lang.Integer.valueOf(Integer.java:999)
at at ch.qos.logback.core.joran.util.StringToObjectConverter.convertArg(StringToObjectConverter.java:62)
at at ch.qos.logback.core.joran.util.PropertySetter.setProperty(PropertySetter.java:117)
at ... 72 common frames omitted
logback版本是1.5.6
我明白了 AbstractSyslogConfig 有 2 个设施设置器的原因：
11:10:40,586 |-WARN in ch.qos.logback.core.joran.util.beans.BeanDescriptionFactory@1c5d2f51 - Class 'org.productivity.java.syslog4j.impl.net.tcp.TCPNetSyslogConfig' contains multiple setters for the same property 'facility'
代码是：
public void setFacility(int facility) {
this.facility = facility;
}
public void setFacility(String facilityName) {
this.facility = SyslogUtility.getFacility(facilityName);
}
有解决办法吗？
根据您的研究，似乎 logback 总是尝试将值转换为整数并失败。我要做的就是使用整数值作为解决方法。
这些值可以在协议文档RFC 5424，
中找到设施和严重性值不规范，但经常使用。 他们 下表中的描述仅供参考 目的。 设施值必须在 0 到 23 范围内（含）。
数值设施 代码
0 kernel messages
1 user-level messages
2 mail system
3 system daemons
4 security/authorization messages
5 messages generated internally by syslogd
6 line printer subsystem
7 network news subsystem
8 UUCP subsystem
9 clock daemon
10 security/authorization messages
11 FTP daemon
12 NTP subsystem
13 log audit
14 log alert
15 clock daemon (note 2)
16 local use 0 (local0)
17 local use 1 (local1)
18 local use 2 (local2)
19 local use 3 (local3)
20 local use 4 (local4)
21 local use 5 (local5)
22 local use 6 (local6)
23 local use 7 (local7)