mvn compile时找不到符合，各位大神帮帮忙，已经好长时间了找不到问题，谢谢！！！

Question

C:\moocwork\code\maven01>mvn compile[INFO] Scanning for projects...[INFO][INFO] ------------------------------------------------------------------------[INFO] Building maven01-model 0.0.1-SNAPSHOT[INFO] ------------------------------------------------------------------------[INFO][INFO] --- maven-resources-plugin:2.5:resources (default-resources) @ maven01-model ---[debug] execute contextualize[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent![INFO] skip non existing resourceDirectory C:\moocwork\code\maven01\src\main\resources[INFO][INFO] --- maven-compiler-plugin:2.3.2:compile (default-compile) @ maven01-model ---[WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent![INFO] Compiling 1 source file to C:\moocwork\code\maven01\target\classes[INFO] -------------------------------------------------------------[ERROR] COMPILATION ERROR :[INFO] -------------------------------------------------------------[ERROR] \moocwork\code\maven01\src\main\java\com\imooc\maven01\model\HelloWorld.java:[4,8] 错误: 找不到符号[INFO] 1 error[INFO] -------------------------------------------------------------[INFO] ------------------------------------------------------------------------[INFO] BUILD FAILURE[INFO] ------------------------------------------------------------------------[INFO] Total time: 1.347s[INFO] Finished at: Thu Jul 06 07:51:01 CST 2017[INFO] Final Memory: 9M/102M[INFO] ------------------------------------------------------------------------[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project maven01-model: Compilation failure[ERROR] \moocwork\code\maven01\src\main\java\com\imooc\maven01\model\HelloWorld.java:[4,8] 错误: 找不到符号[ERROR] -> [Help 1][ERROR][ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.[ERROR] Re-run Maven using the -X switch to enable full debug logging.[ERROR][ERROR] For more information about the errors and possible solutions, please read the following articles:[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureExceptionC:\moocwork\code\maven01>