C:\Users\Hina\Desktop\OpenMRS\openmrs-core\openmrs-module-legacyui>mvn clean install
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] Legacy UI Module                                                   [pom]
[INFO] Legacy UI Module API                                               [jar]
[INFO] Legacy UI Module OMOD                                              [jar]
[INFO]
[INFO] --------------------< org.openmrs.module:legacyui >---------------------
[INFO] Building Legacy UI Module 1.6.0-SNAPSHOT                           [1/3]
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ legacyui ---
[INFO]
[INFO] --- license-maven-plugin:3.0:format (format-license-header) @ legacyui ---
[INFO] Updating license headers...
[INFO]
[INFO] --- maven-install-plugin:2.4:install (default-install) @ legacyui ---
[INFO] Installing C:\Users\Hina\Desktop\OpenMRS\openmrs-core\openmrs-module-legacyui\pom.xml to C:\Users\Hina\.m2\repository\or
g\openmrs\module\legacyui\1.6.0-SNAPSHOT\legacyui-1.6.0-SNAPSHOT.pom
[INFO]
[INFO] ------------------< org.openmrs.module:legacyui-api >-------------------
[INFO] Building Legacy UI Module API 1.6.0-SNAPSHOT                       [2/3]
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ legacyui-api ---
[INFO] Deleting C:\Users\Hina\Desktop\OpenMRS\openmrs-core\openmrs-module-legacyui\api\target
[INFO]
[INFO] --- license-maven-plugin:3.0:format (format-license-header) @ legacyui-api ---
[INFO] Updating license headers...
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ legacyui-api ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 3 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ legacyui-api ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to C:\Users\Hina\Desktop\OpenMRS\openmrs-core\openmrs-module-legacyui\api\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] Reactor Summary for Legacy UI Module 1.6.0-SNAPSHOT:
[INFO]
[INFO] Legacy UI Module ................................... SUCCESS [  1.128 s]
[INFO] Legacy UI Module API ............................... FAILURE [  1.549 s]
[INFO] Legacy UI Module OMOD .............................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  3.330 s
[INFO] Finished at: 2019-11-10T14:28:21+05:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project legacyui
-api: Compilation failure
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[ERROR]
[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
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <args> -rf :legacyui-api