Merge remote-tracking branch 'firm1/master' into doc

.travis.yml

@@ -8,14 +8,18 @@ matrix:
     - os: linux
       dist: trusty
       sudo: required
-      jdk: oraclejdk8
     - os: osx
       osx_image: xcode8
 
 before_install:
   - set JAVA_OPTS=-XX:MaxPermSize=1024m -Xmx1512m -Dfile.encoding=UTF-8
   - set JAVA_TOOL_OPTIONS=-Dfile.encoding=UTF-8
   - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo apt-get install -y rpm ; fi
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo add-apt-repository -y ppa:webupd8team/java ; fi
+  - java -version
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo apt-get update ; fi
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo apt-get install -y oracle-java8-installer ; fi
+  - java -version
 
 script:
   - ./gradlew check -Dzw.username=$ZDS_USERNAME -Dzw.password=$ZDS_PASSWORD -Dzw.github_user=$GITHUB_USER -Dzw.github_token=$GITHUB_TOKEN --info

build.gradle

@@ -5,6 +5,10 @@ plugins {
     id "com.eriwen.gradle.css" version "2.12.0"
 }
 
+if(JavaVersion.current() < JavaVersion.VERSION_1_8){
+    throw new GradleException("This build must be run with java 8 or higher. Current version is " + JavaVersion.current() + ".\nYou should install jdk >= 1.8 from http://www.oracle.com/technetwork/java/javase/downloads and/or check your JAVA_HOME.")
+}
+
 apply from: "http://dl.bintray.com/content/shemnon/javafx-gradle/8.1.1/javafx.plugin"
 
 processResources {