No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?

1.提出问题

[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building ssh 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] >>> tomcat7-maven-plugin:2.2:run (default-cli) > process-classes @ ssh >>>
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ ssh ---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 4 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ ssh ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 8 source files to E:\MavenWorkspace\ssh\target\classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.374 s
[INFO] Finished at: 2018-05-25T21:50:27+08:00
[INFO] Final Memory: 10M/155M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project ssh: Compilation failure
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[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

2.清空项目自动生成的文件。

清空项目下的class文件。