SONARPLUGINS-1582 Improve the script

src/main/assembly/bin/sonar-runner.bat

@@ -11,32 +11,53 @@
 
 
 @REM ==== START VALIDATION ====
-if not "%JAVA_HOME%" == "" goto OkJavaHome
+@REM => JAVA EXEC
+if not "%JAVA_HOME%" == "" goto foundJavaHome
+
+for %%i in (java.exe) do set JAVA_EXEC=%%~$PATH:i
+
+if not "%JAVA_EXEC%" == "" goto OkJava
 
 echo.
-echo ERROR: JAVA_HOME not found in your environment.
+echo ERROR: JAVA_HOME not found in your environment, and no Java 
+echo        executable present in the PATH.
 echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation
+echo location of your Java installation, or add "java.exe" to the PATH
+echo.
+goto end
+
+:foundJavaHome
+if EXIST "%JAVA_HOME%\bin\java.exe" goto foundJavaExeFromJavaHome
+
+echo.
+echo ERROR: JAVA_HOME exists but does not point to a valid Java home
+echo        folder. No "\bin\java.exe" file can be found there.
 echo.
 goto end
 
-:OkJavaHome
+:foundJavaExeFromJavaHome
+set JAVA_EXEC="%JAVA_HOME%\bin\java.exe"
+
+:OkJava
 if NOT "%SONAR_RUNNER_HOME%"=="" goto cleanSonarRunnerHome
 set SONAR_RUNNER_HOME=%~dp0..
 goto run
 
+@REM => SONAR_RUNNER_HOME
 :cleanSonarRunnerHome
 @REM If the property has a trailing backslash, remove it
 if %SONAR_RUNNER_HOME:~-1%==\ set SONAR_RUNNER_HOME=%SONAR_RUNNER_HOME:~0,-1%
 
 
+
 @REM ==== START RUN ====
 :run
 echo %SONAR_RUNNER_HOME%
 
 set PROJECT_HOME=%CD%
 
-"%JAVA_HOME%\bin\java.exe" %SONAR_RUNNER_OPTS% -classpath "%SONAR_RUNNER_HOME%\lib\sonar-runner.jar";"%SONAR_RUNNER_HOME%\lib\sonar-batch-bootstrapper.jar" "-Drunner.home=%SONAR_RUNNER_HOME%" "-Dproject.home=%PROJECT_HOME%" org.sonar.runner.Main %*
+%JAVA_EXEC% %SONAR_RUNNER_OPTS% -classpath "%SONAR_RUNNER_HOME%\lib\sonar-runner.jar";"%SONAR_RUNNER_HOME%\lib\sonar-batch-bootstrapper.jar" "-Drunner.home=%SONAR_RUNNER_HOME%" "-Dproject.home=%PROJECT_HOME%" org.sonar.runner.Main %*
+
 
 
 @REM ==== END EXECUTION ====