Make mvnw usage optional on java presence

experimental/java-spring-boot2-liberty/image/project/.appsody-init.bat

@@ -1 +1,6 @@
-mvnw install -Denforcer.skip=true
+setlocal
+set JAVA_FOUND=0
+where java >nul 2>nul
+if %ERRORLEVEL% EQU 0 set JAVA_FOUND=1
+if defined JAVA_HOME set JAVA_FOUND=1
+if "%JAVA_FOUND%"==1 mvnw install -Denforcer.skip=true

experimental/java-spring-boot2-liberty/image/project/.appsody-init.sh

@@ -1,2 +1,5 @@
 #!/bin/bash
-./mvnw install -Denforcer.skip=true
+which java 2>&1 >/dev/null ; JAVA_KNOWN=$?
+if [ ! -z "$JAVA_HOME" ] || [ $JAVA_KNOWN = "0" ]; then
+  ./mvnw install -Denforcer.skip=true
+fi

incubator/java-microprofile/image/project/.appsody-init.bat

@@ -1 +1,6 @@
-mvnw install -Denforcer.skip=true
+setlocal
+set JAVA_FOUND=0
+where java >nul 2>nul
+if %ERRORLEVEL% EQU 0 set JAVA_FOUND=1
+if defined JAVA_HOME set JAVA_FOUND=1
+if "%JAVA_FOUND%"==1 mvnw install -Denforcer.skip=true

incubator/java-microprofile/image/project/.appsody-init.sh

@@ -1,2 +1,5 @@
 #!/bin/bash
-./mvnw install -Denforcer.skip=true
+which java 2>&1 >/dev/null ; JAVA_KNOWN=$?
+if [ ! -z "$JAVA_HOME" ] || [ $JAVA_KNOWN = "0" ]; then
+  ./mvnw install -Denforcer.skip=true
+fi

incubator/java-spring-boot2/image/project/.appsody-init.bat

@@ -1,4 +1,9 @@
 if not exist %SystemDrive%%HOMEPATH%\.m2\repository\ (
   mkdir %SystemDrive%%HOMEPATH%\.m2\repository
 )
-mvnw install -q -f ./appsody-boot2-pom.xml
+setlocal
+set JAVA_FOUND=0
+where java >nul 2>nul
+if %ERRORLEVEL% EQU 0 set JAVA_FOUND=1
+if defined JAVA_HOME set JAVA_FOUND=1
+if "%JAVA_FOUND%"==1 mvnw install -q -f ./appsody-boot2-pom.xml

incubator/java-spring-boot2/image/project/.appsody-init.sh

@@ -18,4 +18,7 @@ if [ ! -d ~/.m2/repository ]; then
   mkdir -p ~/.m2/repository
 fi
 
-./mvnw install -q -f ./appsody-boot2-pom.xml
+which java 2>&1 >/dev/null ; JAVA_KNOWN=$?
+if [ ! -z "$JAVA_HOME" ] || [ $JAVA_KNOWN = "0" ]; then
+  ./mvnw install -q -f project/appsody-boot2-pom.xml
+fi