报错SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".

报错信息：
SLF4J: Failed to load class “org.slf4j.impl.StaticLoggerBinder”.
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
网上查了很多资料终于解决了！

shiro 例子测试 maven里面jar包添加.

看看自己maven文件缺少哪个，把那个添加进去就可以解决问题
我自己是少了 slf4j-simple 、 slf4j-nop 两个jar包。也就是最后后两个文件。

<dependency>
      <groupId>org.apache.shiro</groupId>
      <artifactId>shiro-all</artifactId>
      <version>1.3.2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/log4j/log4j -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.7.25</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.7.25</version>
      <scope>test</scope>
    </dependency>
       <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-simple</artifactId>
      <version>1.7.25</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-nop -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-nop</artifactId>
      <version>1.7.25</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

好了，终于有正常的输出了：