IDEA springboot 2.0.0.RELEASE解决java.lang.ClassNotFoundException: org.apache.log4j.Logger

问题：

Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 77 common frames omitted

解决：

mvn dependency:tree

项目原先是1.5.9和现在2.0.1的区别在于org.slf4j的依赖不全

        <!--springboot2.0 日志依赖不全-->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.25</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>log4j-over-slf4j</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
        </dependency>