解决Tomcat过滤器初始化参数为Null：Log4j 2.x迁移后的配置解析

<filter>
    <filter-name>newsession</filter-name>
    <display-name>newsession</display-name>
    <description>newsession</description>
    <filter-class>com.demo.custom.filter.NewSession</filter-class>
    <init-param>
        <param-name>DomainName</param-name>
        <param-value>.testlab.com</param-value>
    </init-param>
    <init-param>
        <param-name>DomConfigFile</param-name>
        <param-value>/opt/tomcat/webapp/demoapp/WEB-INF/classes/NAM_log4j.xml</param-value>
    </init-param>
    <init-param>
        <param-name>customPropFile</param-name>
        <param-value>/opt/tomcat/webapp/demoapp/WEB-INF/classes/custom_resources.properties</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>newsession</filter-name>
    <url-pattern>/idff/sso</url-pattern>
</filter-mapping>

public void init(FilterConfig fConfig) throws ServletException {
    try{
        domainName = fConfig.getInitParameter("DomainName");
        domConfigFile=fConfig.getInitParameter("DomConfigFile");
        custom_resources=fConfig.getInitParameter("customPropFile");
    }catch(Exception e){
        myLogger.error(e.getMessage());
    }
    // ... 后续对null值的处理
    if(domConfigFile==null){
        myLogger.error("domConfigFile got null from web.xml, setting hardcoded value");
        // ...
    }
    if(custom_resources==null){
        myLogger.error("custom_resources got null from web.xml, setting hardcoded value");
        // ...
    }
}

ERROR com.demo.custom.filter.NewSession - domConfigFile got null from web.xml, setting hardcoded value
ERROR com.demo.custom.filter.NewSession - custom_resources got null from web.xml, setting hardcoded value
main ERROR Error processing element category ([Configuration: null]): CLASS_NOT_FOUND
main ERROR Unknown object "root" of type org.apache.logging.log4j.core.config.LoggerConfig is ignored: try nesting it inside one of: ["Appenders", "Loggers", "Properties", "Scripts", "CustomLevels"]

<Configuration status="WARN"> <!-- status属性用于设置Log4j自身的日志级别 -->
    <Appenders>
        <Console name="STDOUT" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{MM/dd HH:mm:ss} %-5p %30.30c %x - %m%n"/>
        </Console>
        <RollingFile name="RollingFile" fileName="/opt/tomcat/logs/MyCustomClassLogs.log" filePattern="/opt/tomcat/logs/MyCustomClassLogs.log-%i.log">
            <PatternLayout>
                <pattern>%d{MM/dd HH:mm:ss} %-5p %30.30c %x - %m%n</pattern>
            </PatternLayout>
            <Policies>
                <SizeBasedTriggeringPolicy size="5 MB" />
            </Policies>
            <DefaultRolloverStrategy max="5"/>
        </RollingFile>
        <RollingFile name="ResetClass" fileName="/opt/tomcat/logs/resetTrace.log" filePattern="/opt/tomcat/logs/resetTrace.log-%i.log">
            <PatternLayout>
                <pattern>%d{MM/dd HH:mm:ss} %-5p %30.30c %x - %m%n</pattern>
            </PatternLayout>
            <Policies>
                <SizeBasedTriggeringPolicy size="5 MB" />
            </Policies>
            <DefaultRolloverStrategy max="5"/>
        </RollingFile>
    </Appenders>
    <Loggers>
        <Logger name="com.demo.custom.filter.ResetClass" level="TRACE" additivity="false">
            <AppenderRef ref="ResetClass"/>
        </Logger>
        <Logger name="com.demo.custom.test.MyCustomClass" level="TRACE" additivity="false">
            <AppenderRef ref="RollingFile"/>
        </Logger>
        <Root level="error">
            <AppenderRef ref="STDOUT"/>
        </Root>
    </Loggers>
</Configuration>