Application is using Java 6 from Apple instead of Java 7 from Oracle on Mac OS X?

Question

I am testing my current application with Mac OS X which has Java 7 from Oracle installed. Instead using Java 7 from Oracle, it's using Java 6 from Apple. The default system output of java -version is showing 7.

I tried most of the things mentioned in different sites, but I was unable to fix this issue.

JAVA_HOME is also properly set.

I am using the Mac only for testing purposes. I really need some guidance on this.

When I run it with Eclipse by selecting JRE 7, it runs properly. Thus there is nothing wrong with the application. I am missing something on Mac OS X.

My Java system environment looks like this:

• OS X version

  10.8

• /usr/libexec/java_home -V

  Matching Java Virtual Machines (3): 1.7.0_12, x86_64: "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_12.jdk    1.6.0_37-b06-434, x86_64: "Java SE 6" /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home 1.6.0_37-b06-434, i386: "Java SE 6" /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home  /Library/Java/JavaVirtualMachines/jdk1.7.0_12.jdk/Contents/Home 

• /usr/libexec/java_home

  /Library/Java/JavaVirtualMachines/jdk1.7.0_12.jdk/Contents/Home 

• echo $JAVA_HOME

  /Library/Java/JavaVirtualMachines/jdk1.7.0_12.jdk/Contents/Home/ 

• JAVA_ARCH is not set

• /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java -version

  java version "1.7.0_12-ea" 

• ls /Library/Java/JavaVirtualMachines

  jdk1.7.0_12.jdk 

• /System/Library/Frameworks/JavaVM.framework/Commands/java -version

  java version "1.6.0_37" 

I guess my current JDK is pointing to something wrong.

Answer 1

Issue

Your Mac OS X application bundle has been created with an app bundler which is not compatible with Oracle's Java 7 package. The bundler you were using could be, for example, Jar Bundler provide by Apple which only works for Apple's Java 6 System Packages.

Apple has given up support for Java as an integrated System Packages from Java 7 and later. As a consequence you have to go for the Oracle Java 7 Third Party package and their application package bundle solution. This allows you to create and deploy Oracle Java 7 based application bundles on Mac OS X 10.7.3 and onwards.

The underlying technical issue you are facing is Apple's native Objective-C based JavaAppLauncher binary and the format it uses in Info.plist is only working with Apple's Java 6 System Packages and the JavaAppLauncher Info.plist combination coming from Oracle is only working for Oracle's Java 7 Packages.

As you are using a JavaAppLauncher supporting Apple's Java 6 System Packages, it will always pick up the Apple Java 6 System Package installed on your Mac.

There is a video, where Scott Kovatch, the lead engineer for the Mac OS X port of the Java platform at Oracle is talking on DEVOXX about how app bundling for Oracle Java 7 is working in great detail.

Solution

To create app bundles based for Mac OS X 10.7.3 and onwards based on

• Oracle's Java SE 7 (JRE 1.7.x)
• OpenJDK Java SE 7 (JRE 1.7.x)

and above, you have to use Oracle's app bundler

• lib/appbundler-1.0.jar containing the Ant Task com.oracle.appbundler.AppBundlerTask

With Oracle's app bundler you have now the choice to run your packaged app with the default Oracle Java 7 Package installed on your Mac here:

• /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/

or the Oracle Java 7 JRE you inline in your packaged application

• MyJavaMacOSXApp.app/Contents/PlugIns/

Note: There are pros and cons for both approaches, but you need the last one with your own JRE if you want to go to the Apple App Store with your bundled app.

What needs to be done

• Download appbundler-1.0.jar and move it to <project>/lib/appbundler-1.0.jar

• Add the following to your <project>/build.xml

  <property environment="env" />  <taskdef      name="bundleapp"      classname="com.oracle.appbundler.AppBundlerTask"      classpath="lib/appbundler-1.0.jar" />  <target name="bundle">     <bundleapp          outputdirectory="dist"          name="MyJavaMacOSXApp"          displayname="My Java Mac OS X App"          identifier="com.example.MyJavaMacOSXApp"          shortversion="1.0"         applicationCategory="public.app-category.developer-tools"         mainclassname="com.example.MyJavaMacOSXApp">         <runtime dir="${env.JAVA_HOME}" />         <classpath file="dist/MyJavaMacOSXApp.jar" />     </bundleapp> </target> 

  Note: You need to replace MyJavaMacOSXApp with your application data. You can find here some additional AppBundlerTask options, as this example shows only how how it works in its simplest form.

• After you run the bundle target with ant bundle you will find MyJavaMacOSXApp.app in the <project>/dist directory.

What does the <runtime dir="${env.JAVA_HOME}" /> element?

Inlining Oracle Java 7 Package (JRE)

The Ant target above copies the Oracle Java 7 Package (JRE) from your

• JAVA_HOME

into

• MyJavaMacOSXApp.app/Contents/PlugIns

So the application package is totally self contained and does not need an Oracle Java 7 Package (JRE) installed on the target system at all. Like you can see in the following screen shot of such a deployed MyJavaMacOSXApp.app:

Wiring default Oracle Java 7 Package (JRE)

If you want to use the default Oracle Java 7 Package (JRE) installed on the application bundle target Mac under

• /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/

you have to remove the

• <runtime dir="${env.JAVA_HOME}" />

element fromt the bundle task. Like you can see in the following screen shot of such a deployed MyJavaMacOSXApp.app:

Source of MyJavaMacOSXApp.java

package com.example;  import java.awt.*; import javax.swing.*;  public class MyJavaMacOSXApp extends JPanel {      public MyJavaMacOSXApp() {         JLabel versionLabel = new JLabel("java.version=" + System.getProperty("java.version"));         JLabel homeLabel = new JLabel("java.home=" + System.getProperty("java.home"));         setLayout(new BorderLayout());         add(versionLabel, BorderLayout.PAGE_START);         add(homeLabel, BorderLayout.PAGE_END);     }      private static void createAndShowGUI() {         JFrame frame = new JFrame("MyJavaMacOSXApp");         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);         MyJavaMacOSXApp newContentPane = new MyJavaMacOSXApp();         newContentPane.setOpaque(true);          frame.setContentPane(newContentPane);         frame.pack();         frame.setVisible(true);     }      public static void main(String[] args) {         SwingUtilities.invokeLater(new Runnable() {             public void run() {                 createAndShowGUI();             }         });     } } 

What if my app has multiple jar files?

Just add as many <classpath file="dist/additional.jar" /> entries as you need.

Note: The order of elements in the bundle task isn't preserved at runtime of your bundled app. The java.class.path gets built up at runtime by the native JavaAppLauncher as it reads in the *.jars from MyJavaMacOSXApp.app/Contents/Java directory.

---

Just for completeness, this is how Info.plist looks like:

<?xml version="1.0" ?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0">     <dict>         <key>CFBundleDevelopmentRegion</key>         <string>English</string>         <key>CFBundleExecutable</key>         <string>JavaAppLauncher</string>         <key>CFBundleIconFile</key>         <string>GenericApp.icns</string>         <key>CFBundleIdentifier</key>         <string>com.example.MyJavaMacOSXApp</string>         <key>CFBundleDisplayName</key>         <string>My Java Mac OS X App</string>         <key>CFBundleInfoDictionaryVersion</key>         <string>6.0</string>         <key>CFBundleName</key>         <string>MyJavaMacOSXApp</string>         <key>CFBundlePackageType</key>         <string>APPL</string>         <key>CFBundleShortVersionString</key>         <string>1.0</string>         <key>CFBundleSignature</key>         <string>????</string>         <key>CFBundleVersion</key>         <string>1</string>         <key>NSHumanReadableCopyright</key>         <string></string>         <key>LSApplicationCategoryType</key>         <string>public.app-category.developer-tools</string>         <key>JVMRuntime</key>         <string>jdk1.7.0_17.jdk</string>         <key>JVMMainClassName</key>         <string>com.example.MyJavaMacOSXApp</string>         <key>JVMOptions</key>         <array>         </array>         <key>JVMArguments</key>         <array>         </array>     </dict> </plist>  

Important documents this answer is based on:

1. http://docs.oracle.com/javase/7/docs/technotes/guides/jweb/packagingAppsForMac.html
2. http://java.net/projects/appbundler/pages/Home
3. http://java.net/downloads/appbundler/appbundler.html
4. http://intransitione.com/blog/take-java-to-app-store/
5. http://www.parleys.com/#st=5&id=2891&sl=37

There is also a well maintained fork of appbundler itself, with many more features and bugfixes.

• https://bitbucket.org/infinitekind/appbundler

Answer 2

The Java version required by the app is probable specified in the application's metadata. If you right-click on the app and select Show Package Contents and browse to the Info.plist file, you should find entries which define the JVM that the application will use. E.g.

    <key>JVMVersion</key>     <string>1.5</string> 

OSX may choose to use a lower JVM if the application requests it.