1. 来龙去脉

生成日志非常重要的程序，需要考虑未来切换日志方案的可能。在使用nutz时，nutz会提供一套日志的adaptor，方便以后的切换。具体使用时，可以在程序中使用nutz提供的log相关api，而不是直接使用log4j1，log4j或者其他的日志实现。

升级到nutz-1.r.58后，这种方法会带来nutz自身的日志会打印异常，log4j找不到appender了。具体日志（程序启动后）如下：

log4j:WARN No appenders could be found for logger (org.nutz.resource.Scans).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

2. 解决方案

2.1. 版本说明

• log4j2-2.3
• nutz-1.b.53, nutz-1.r.57, nutz-1.b.58尝试。

2.2. 核心通用代码及配置

2.2.1. 代码

import com.hoperun.epu.base.nutz.IocMaster;
import org.apache.logging.log4j.ThreadContext;
import org.nutz.dao.Dao;
import org.nutz.dao.Sqls;
import org.nutz.dao.impl.sql.callback.FetchTimestampCallback;
import org.nutz.dao.sql.Sql;
import org.nutz.ioc.Ioc;
import org.nutz.log.Log;
import org.nutz.log.Logs;public class AK47 {private static Log log = null;private static Ioc ioc = null;static {System.setProperty("log4j.configurationFile", "etc/log4j2.xml");log = Logs.get();}public static void main(String[] args) {ThreadContext.put("threadName", Thread.currentThread().getName());Thread.currentThread().setName("ak47-main");ioc = IocMaster.getInstance();welcome();}private static void welcome() {System.out.println("***************************************************");System.out.println("Application: AK47");System.out.println("Version:     0.1.0");System.out.println("Description: A date generator and loader");System.out.println("***************************************************");log.info("AK47 has started. Please enjoy it!");}
}

2.2.2. Log4j2配置

<?xml version="1.0" encoding="UTF-8"?>
<configuration status="info" packages="com.rhfdz.epu"><properties><!-- 控制台输出日志格式 --><property name="patterns.console">%d %-5p [%t] %C{1} - %m%n</property><!-- 日志文件输出日志格式 --><Property name="patterns.file">%d %-5p [%t] %C - %m%n</Property><!-- 日志文件大小 --><Property name="file.size">50 MB</Property><!-- 日志文件最大个数 --><Property name="file.maxIndex">10</Property></properties><appenders><console name="console" target="SYSTEM_OUT"><!--这个都知道是输出日志的格式--><PatternLayout pattern="${patterns.console}"/></console><routing name="routing"><routes pattern="$${thread:threadName}"><route><rollingFile name="logFile-${thread:threadName}"fileName="log/${thread:threadName}.log"filePattern="log/$${date:yyyy-MM}/${thread:threadName}-%d{MM-dd-yyyy}-%i.log.gz"><patternLayout pattern="${patterns.file}" /><policies><sizeBasedTriggeringPolicy size="${file.size}" /></policies><defaultRolloverStrategy max="${file.maxIndex}" /></rollingFile></route></routes></routing><!--<async name="async" bufferSize="1000" includeLocation="true">--><!--<appenderRef ref="routing" />--><!--<appenderRef ref="console" />--><!--</async>--></appenders><loggers><logger name="com.rhfdz.epu" level="debug"/><logger name="org.nutz" level="info"/><root level="info"><!--<appenderRef ref="async" />--><appenderRef ref="console" /><appenderRef ref="routing" /></root></loggers>
</configuration>

2.3. 不同nutz版本的处理方法

2.3.1. nutz-1.b.53

2.3.1.1. 日志效果

ALL Nutz Log via Log4jLogAdapter
2016-10-12 22:14:16,301 INFO  [main] Logs - Nutz is licensed under the Apache License, Version 2.0 .
Report bugs : https://github.com/nutzam/nutz/issues
2016-10-12 22:14:17,711 INFO  [ak47-main] AnnotationIocLoader - Scan complete ! Found 5 classes in 1 base-packages!
beans = ["samplePerfKpiAnalyzer", "littleBlueBird", "samplePerfDao", "skGenerator", "generalStatDao"]
2016-10-12 22:14:17,720 INFO  [ak47-main] NutIoc - NutIoc init begin ...
2016-10-12 22:14:17,722 INFO  [ak47-main] NutIoc - ... NutIoc init complete
***************************************************
Application: AK47
Version:     0.1.0
Description: A date generator and loader
***************************************************
2016-10-12 22:14:17,723 INFO  [ak47-main] AK47 - AK47 has started. Please enjoy it!

2.3.1.2. maven依赖

        <dependency><groupId>org.nutz</groupId><artifactId>nutz</artifactId><version>1.b.53</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-api</artifactId><version>2.3</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>2.3</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-1.2-api</artifactId><version>2.3</version></dependency>

2.3.2. nutz-1.r.57

2.3.2.1. 日志效果

2016-10-12 22:21:01,417 INFO  [ak47-main] AnnotationIocLoader - Found 5 classes in 1 base-packages!
beans = ["samplePerfKpiAnalyzer", "littleBlueBird", "samplePerfDao", "skGenerator", "generalStatDao"]
2016-10-12 22:21:01,443 INFO  [ak47-main] NutIoc - NutIoc init begin ...
2016-10-12 22:21:01,446 INFO  [ak47-main] NutIoc - ... NutIoc init complete
***************************************************
Application: AK47
Version:     0.1.0
Description: A date generator and loader
***************************************************
2016-10-12 22:21:01,446 INFO  [ak47-main] AK47 - AK47 has started. Please enjoy it!

与1.b.53相比INFO日志有所变化，少了如下内容

ALL Nutz Log via Log4jLogAdapter
2016-10-12 22:14:16,301 INFO  [main] Logs - Nutz is licensed under the Apache License, Version 2.0 .
Report bugs : https://github.com/nutzam/nutz/issues

2.3.2.2. maven依赖

与nutz-1.b.53的依赖配置基本相同，仅对nutz依赖做调整如下

        <dependency><groupId>org.nutz</groupId><artifactId>nutz</artifactId><version>1.r.57</version></dependency>

2.3.3. nutz-1.r.58

2.3.3.1. 日志效果

2016-10-12 22:26:03,466 INFO Log4j appears to be running in a Servlet environment, but there's no log4j-web module available. If you want better web container support, please add the log4j-web JAR to your web archive or server lib directory.
2016-10-12 22:26:05,094 INFO  [ak47-main] AnnotationIocLoader - Found 5 classes in 1 base-packages!
beans = ["samplePerfKpiAnalyzer", "littleBlueBird", "samplePerfDao", "skGenerator", "generalStatDao"]
2016-10-12 22:26:05,111 INFO  [ak47-main] NutIoc - NutIoc init begin ...
2016-10-12 22:26:05,114 INFO  [ak47-main] NutIoc - ... NutIoc init complete
***************************************************
Application: AK47
Version:     0.1.0
Description: A date generator and loader for nwims
***************************************************
2016-10-12 22:26:05,114 INFO  [ak47-main] AK47 - AK47 has started. Please enjoy it!

2.3.3.2. maven依赖

与nutz-1.b.53的依赖配置基本相同，仅对nutz依赖做调整如下

<dependency><groupId>org.nutz</groupId><artifactId>nutz</artifactId><version>1.r.58</version><!-- 1.r.58的bug，需要excludelog4j，不然nutz会找不到appender --><!-- 参考：https://nutz.cn/yvr/t/1uj0eaetdei4kqr9qsipb53ics --><exclusions><exclusion><artifactId>log4j</artifactId><groupId>log4j</groupId></exclusion></exclusions></dependency>

如果不增加对log4j的exclusion，则会出现文章开头的情况。

3. 原始贴地址

本文内容的原始的讨论过程在nutz社区：https://nutz.cn/yvr/t/1uj0eaetdei4kqr9qsipb53ics