这个 Log4j 的报错，会导致系统的 log4j.xml 配置

这个 Log4j 的报错，会导致系统的 log4j.xml 配置（失效）被覆盖重置。

2018-04-27 17:31:43.248 org.slf4j.helpers.Util report
System.err: SLF4J: Class path contains multiple SLF4J bindings.
2018-04-27 17:31:43.250 org.slf4j.helpers.Util report
System.err: SLF4J: Found binding in [jar:file:/Users/jack/aipqa/swork.info/swork.info.server/target/swork-info/WEB-INF/lib/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
2018-04-27 17:31:43.250 org.slf4j.helpers.Util report
System.err: SLF4J: Found binding in [jar:file:/Users/jack/aipqa/swork.info/swork.info.server/target/swork-info/WEB-INF/lib/slf4j-log4j12-1.7.7.jar!/org/slf4j/impl/StaticLoggerBinder.class]
2018-04-27 17:31:43.251 org.slf4j.helpers.Util report
System.err: SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
2018-04-27 17:31:43.640 org.slf4j.helpers.Util report
System.err: SLF4J: Actual binding is of type [ch.qos.logback.classic.util.ContextSelectorStaticBinder]

含义为：
发生jar包冲突了：
分别为：

[jar:file:/Users/jack/aipqa/swork.info/swork.info.server/target/swork-info/WEB-INF/lib/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]

[jar:file:/Users/jack/aipqa/swork.info/swork.info.server/target/swork-info/WEB-INF/lib/slf4j-log4j12-1.7.7.jar!/org/slf4j/impl/StaticLoggerBinder.class]

解决方案：

移除其中一个jar包即可。

        <dependency>
            <groupId>xxx</groupId>
            <artifactId>yyy</artifactId>
            <version>1.0-SNAPSHOT</version>
            <exclusions>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-classic</artifactId>
                </exclusion>
            </exclusions>
        </dependency>