一. maven 编写出错及解决办法：
出错信息如下：
Fatal Error: Unable to find package java.lang in classpath or bootclasspath [INFO] ------------------------------------------------------------- [ERROR] COMPILATION ERROR : [INFO] ------------------------------------------------------------- [ERROR] An unknown compilation problem occurred [INFO] 1 error [INFO] ------------------------------------------------------------- [INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 4.145 s [INFO] Finished at: 2018-10-09T16:26:39+08:00 [INFO] Final Memory: 33M/322M [INFO] ------------------------------------------------------------------------ [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.5.1:compile (default-compile) on project xdf_grow: Compilation failure [ERROR] An unknown compilation problem occurred [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/MojoFailureException
主要有2点错误信息：
1. Fatal Error: Unable to find package java.lang in classpath or bootclasspath
2. Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.5.1:compile (default-compile) on project xdf_grow: Compilation failure
解决查询：
修改 目录下 pos.xml 文件，具体内容如下：
这里是查找PATH 路径，window改为分号，linux改为冒号
