docs for relative $JAVA_HOME

Author: tofi86

CHANGELOG.md

@@ -12,6 +12,9 @@ ChangeLog
 * Switch to `/bin/bash` with changes in #35
 * Add support for arrays of VMOptions in Apple style Info.plists (PR #25, Thanks to @spectre683 for his contribution)
 * Pass command line arguments through to the application (PR #31, Thanks to @dbankieris for his contribution)
+* Allow specifying `$JAVA_HOME` relative to `$AppPackageFolder` (PR #26, Thanks to @toonetown for his contribution)
+  * This allows you to set a relative `$JAVA_HOME` via the `<LSEnvironment>` Plist key
+  * Which means you can bundle a custom version of Java inside your app!
 
 ### v1.0.1 (2015-11-02)
 * Improved display error message with applescript (PR #22, Thanks to @ygesnel for his initial contribution)

README.md

@@ -68,6 +68,8 @@ The name of the *main class* is also retrieved from `Info.plist`. If no *main cl
 There is some *foo* happening to determine which Java versions are installed – here's the list in which order system properties are checked:
 
 1. system variable `$JAVA_HOME`
+  * can also be set to a relative path using the [`<LSEnvironment>` Plist dictionary key](https://developer.apple.com/library/content/documentation/General/Reference/InfoPlistKeyReference/Articles/LaunchServicesKeys.html#//apple_ref/doc/uid/20001431-106825)
+    * which allows for bundling a custom version of Java inside your app!
 2. highest available Java version found in one of these locations:
   * `/usr/libexec/java_home` symlinks
   * Oracle's JRE Plugin: `/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java`

src/universalJavaApplicationStub

@@ -13,7 +13,7 @@
 #                                                                                #
 # @author    Tobias Fischer                                                      #
 # @url       https://github.com/tofi86/universalJavaApplicationStub              #
-# @date      2016-10-11                                                          #
+# @date      2016-11-20                                                          #
 # @version   1.0.1                                                               #
 #                                                                                #
 #                                                                                #
@@ -371,9 +371,14 @@ oracle_jre_version=`extractJavaMajorVersion "${oracle_jre_plugin}"`
 
 # first check system variable "$JAVA_HOME"
 if [ -n "$JAVA_HOME" ] ; then
+
+    # PR 26: Allow specifying "$JAVA_HOME" relative to "$AppPackageFolder"
+    # which allows for bundling a custom version of Java inside your app!
     if [[ $JAVA_HOME == /* ]] ; then
+      # if "$JAVA_HOME" starts with a Slash it's an absolute path
 	    JAVACMD="$JAVA_HOME/bin/java"
     else
+      # otherwise it's a relative path to "$AppPackageFolder"
       JAVACMD="$AppPackageFolder/$JAVA_HOME/bin/java"
     fi