Unless you absolutely need Java on your Mac, don't bother with it. And if you have to, get ready to de-adware your Mac. In Mac OS X, you can check by going into Applications → Utilities and looking for an application called 'Java Preferences.' If it's not there, you don't have Java installed; if is, you can open.
In the past two articles you have seen how to customize your Java application so that it looks and feels more like a native Macintosh application when running on Mac OS X without changing the end user experience on other platforms. A combination of runtime properties and coding changes that targeted Mac OS X specific APIs made a big difference to that audience.
Recall that Mac OS X is a melding of two worlds. Hard core UNIX programmers can pop open a Terminal window and write their Java code using vi and compile and run it from the command line. There is, however, the more traditional Mac audience that interacts with their computer through a friendly UI that follows Apple Human Interface guidelines.
In this article, we look at deploying your Java application. The technical geek audience might be happy with running a class with a
main()
method from the command line but the wider audience expects a double-clickable icon that looks and acts like every other native application. In this article, we travel from one end of the spectrum to the other to broaden your potential user base.Although you should 'test everywhere', your build machine may not be a Mac. Fortunately, as you will see, a double-clickable Macintosh application is just a directory with some special contents and a name that ends with
.app
. Even on a Windows machine you should be able to modify your build script to package up a Mac-specific version of your application.Primitive Distributions
Because Mac OS X ships with J2SE 1.4.1 and J2SE 1.3.1, you can distribute your application as class files or jar files and - in theory - your customer could run your application from the Terminal application. We start with these models and quickly move to double-clickable jar files and shell scripts.
Mariadb for macos. For this article, use the Java Sound Demo as the running example. Download and unzip the zip file. Inside the
JavaSoundDemo
directory you will find the source files inside of the src
subdirectory, a jar file, audio files, and html files that we will not use.![Java Java](/uploads/1/1/8/6/118678932/558139123.png)
Raw Class Files
![Do i need java on my macbook pro Do i need java on my macbook pro](/uploads/1/1/8/6/118678932/305684448.png)
As a developer, you don't think twice about compiling the source files and running the application using the command line. Compiling the eight files in the
src
directory generates fifty class files. You can then run the sample application from the command line like this.java JavaSound
The Java Sound Demo starts up. We haven't customized the application in any way so the menu appears at the top of the JFrame and not where Macintosh users expect. The application looks like this out of the box.
You have done this compile and run step so many times that you hardly think twice about it. Think of the least technical person you know and ask whether they would be likely to follow these steps to run your application if a competing application were easier to install and run.
This example demonstrates two separate areas of usability. Once we got the application up and running it looked good and ran fine. You would not, however, want to distribute an application to an end user this way. You would have to somehow bundle up the fifty class files for easy download and installation. You would then have to provide instructions for running the application using, in the case of Mac OS X, the Terminal application.
Jar Files
If you are going to have to package up the class files for distribution anyways, you may as well produce a jar file. And, if you are going to produce a jar file, it ought to be executable. In the case of the Java Sound Demo, the file
JavaSoundDemo.jar
is executable. Because Mac OS X ships with the Jar Launcher application, the end user needs only double click on the jar file and the application will launch.To make the jar file executable, the manifest must include the name of the Main class file. Unjar
JavaSoundDemo.jar
with the command jar xvj JavaSoundDemo.jar
. Here's the file META-INF/MANIFEST.MF
.Shell Scripts and Helper Applications
For larger or more complicated applications you are likely to have more than one jar file along with resource files. A common strategy for targeting multiple platforms is to include a batch file and a shell script. Choose the non-platform specific download from the NetBeans homepage. Inside of the bin subdirectory you will find applications for running NetBeans on a variety of platforms.
The shell script
runide.sh
can be run from the command line like this.sh runide.sh -jdkhome /Library/Java/Home
The NetBeans IDE starts up with this decidedly non-Mac OS X look and feel.
You could, of course, modify the shell script to modify this look and feel, but the NetBeans developers decided on a different approach. Even though the typical NetBeans audience member is technically competent, there should be a friendlier way to start the IDE. They have created a native Mac OS X application called
NetBeansLauncher
.The version of
NetBeansLauncher
that is included in the generic NetBeans download is a good next step. You will see how the team took it farther in the next section. On a Mac OS X computer you can double click on the macosx_launcher.dmg
file inside of the bin
directory. This is a disk image. Drag the NetBeansLauncher
from the expanded disk image back into the bin
directory. Now double click on the NetBeansLauncher
. The ReadMe file that was also in the disk image provides the following information about usage.When launched for the first time, NetBeansLauncher needs to find NetBeans root directory. First it looks into NetBeansLauncher.app itself. If it does not find NetBeans root directory there user must specify NetBeans root directory manually.
For this download, the first time the user starts up the
NetBeansLauncher
, they need to navigate to the netbeans
directory. After that, double clicking on the NetBeansLauncher
starts up the NetBeans IDE as if it were any other native Mac OS X application.First Class Mac OS X Applications
If you download the Mac OS X disk image from the NetBeans distribution and mount it you may be surprised at the simplicity of what you find. Unlike the complex structure visible in the other distributions, you will see five files with documentation and a single application. To install, you can move this
NetBeansLauncher
application anywhere on your hard drive. Double click on it and the NetBeans IDE starts right up.This is the experience that is expected on Mac OS X. The package structure and complexity is hidden from the user and they can't accidentally move a file that renders the IDE unusable. In this section we'll look more closely at the package structure and how to create a Mac OS X application whether or not our build machine is a Mac.
Packages in Mac OS X
Consider again the sentence from the
NetBeansLauncher
instructions that says in order to locate the NetBeans root directory, 'First it looks into NetBeansLauncher.app itself.' This implies that NetBeansLauncher
is a directory with the name 'NetBeansLauncher.app'. In the mounted disk image, either right click or Ctrl-click on the NetBeansLauncher icon and choose to 'Show Package Contents'.The structure is the same for all Mac OS X applications. There is a
Contents
directory with an XML file named info.plist
, a text file named PkgInfo, a MacOS directory, and a Resources directory. If you don't have a creator code registered with Apple the PkgInfo text file should contain only the following.If you have a creator code, use it in place of the question marks. Ordinarily the MacOS folder contains a small stub file that launches the Java VM. In this case the NetBeans team has written their own application. We will look more closely at a property list file in the next section. For now, take a look at the contents of the
Resources
directory.You can see the contents of the same
netbeans
package inside of the Resources
subdirectory. This is your key to deploying on Mac OS X. Add in the necessary pieces and then just bundle up your ordinary distribution in the appropriate location. If you have a more flexible build process you should also strip out those pieces that aren't needed for the Mac OS X application such as the Windows executables.If you are interested in digging deeper into the structure of a Mac OS X application, you will find more information in the Apple publication Anatomy of a Bundle.
Creating 'Native' Java Applications on Mac OS X
If you develop on Mac OS X you can use the
Jar Bundler
application to turn jar files into Mac OS X applications. Jar Bundler
is distributed with the other developer tools and is located in Developer/Applications/
. Start it, select the 'Classpath and Files' tab and add the file JavaSoundDemo.jar
.Select the 'Build Information' tab. For 'Main Class', navigate to the
JavaSoundDemo.jar
file again and select JavaSound
from the drop down list. This list is populated by any classes in the jar file containing a main()
method. Accept all of the default settings for the options. You can use the default Java application icon or you can create your own. The icon you see below started as a screen shot of the running Java Sound Demo and was transformed into an icon using the IconComposer
application that is also distributed as part of the developer tools.Press 'Create Application' and enter the name 'JavaSoundDemo'. A Mac OS X application is created for you. You can show the package contents of the generated application as before. You can view the property list with Apple's Property List Editor or with any text editor. It is just an XML file with properties stored as name - value pairs.
The Java properties indicate the location of the jar file, the name of the Main class, and the version of the JRE to be used. The other properties include a pointer to the icon file and to the Java application stub file that is the native executable.
Creating Mac OS X Java Applications on Other Platforms
Take a look at the contents of the package that was generated by
Jar Bundler
on Mac OS X.On another platform you need to duplicate this structure. To create an application named 'JavaSoundDemo' on, say, a Windows machine, start by creating a directory and naming it
JavaSoundDemo.app
. Next, create a subdirectory named Contents
. Inside of Contents
you will need a MacOS
directory with the JavaAPplicationStub
. You can create the PkgInfo
text file and your Info.plist
can also be generated by hand and should contain the following XML.You will need a
Resources
directory with a Java
subdirectory into which you put the JavaSoundDemo.jar
file. In other words, with the exception of the JavaApplicationStub
and the music.icns
file, everything else can be created on another platform.If you use Ant you can easily add a target that takes your jar files, images, and other resources and bundles it up as a Mac OS X application bundle that includes the plist file and Java application stub in the appropriate locations. Every time you create a new build you will automatically have your Mac OS X version. You can also find a growing number of Ant tasks that automate some of the steps outlined in this article.
Summary
When it comes time to deploy your Java application, consider the ease of use of your target audience. Even developers appreciate the double clickable version of the NetBeans IDE. Creating a Java application that looks and feels like a native application does not require a lot of extra work and can easily be integrated into your build process even if your build machine runs a different operating system.
For More Information
Java is a programming language by Oracle that was often used by websites for online games and to do heavy computational tasks in the browser but how many websites still use Java? And do you still need it installed on your PC?
Over a decade ago Java was almost obligatory for computer users as it was so widely used by websites but what about today…
Why Worry About Java?
I have previously reported on another major security vulnerability in Oracle’s Java.
Gaping security holes in Java are nothing new but what made that one even worse is that Oracle were allegedly warned 4 months before – but did nothing, leaving millions of users vulnerable to attack…
With that sort of attitude to protection, the most effective security for your computer would be to uninstall Java completely if you don’t need it – but do you?
How Many Websites Use Java in 2020?
According to research from W3Techs, only about 0.02% of all the active websites in the world still use Java on the client side (i.e. within your web browser). That’s only 2 in every 10,000 websites and that ratio is decreasing year on year.
So you might expect that nobody would still have the Java plugin installed?
However, 15% of our visitors at TechLogon still have it enabled in their browser – and the global average is similar. It is this popularity that still makes Java a target for malware.
But if it’s only required by about 2 in every 10,000 websites, why do so many people still have Java installed and enabled in their browser? There may be several reasons:
1. Offline Applications May Use Java
Some offline apps can still make use of Java e.g. Adobe Creative Suite and OpenOffice / LibreOffice suite (mainly the Database module). Users of such programs may feel they have little choice but to keep Java installed if they want to use all the functionality of the suite.
Tip: you can keep Java installed, for use by offline apps, but disable the Java plugin in your browser – this would prevent web based vulnerabilities from being exploited:
2. Popular Websites May Use Java
I’ve reviewed before how many active websites there are in the world – about 190 million. So even a lowly 0.02% figure means that up to 38,000 websites may still use Java.
These include a few popular sites (e.g. Udemy) and other sites offering calculation-heavy content (e.g. 3D maps, financial trading, mortgage calculators). However, these sites are only likely to be of interest to a very small percentage of internet users.
Tip: if you regularly visit a website which needs Java then consider installing a new web browser (which has Java enabled) to visit it – and use your regular browser (e.g Chrome or Firefox which have Java disabled) for normal browsing on all other websites.
3. Lack Of User Knowledge About Java
In my PC repair business I find that Java is often a forgotten relic on customer’s computers – often they don’t know what it is and so are afraid to remove it – or to update it which is even worse…
Tip: if you have no good reason to keep Java installed, and you don’t visit one of the few sites that still use it, there are many security advantages to uninstalling it completely. You could always install it again in future if necessary – and at least you’d be sure to have an up to date version.
Conclusion
Only 0.02% of active websites in the world still use Java within the web browser – about 2 in 10,000 sites.
The vast majority of computer users could therefore uninstall Java or at least disable it in their web browser for much better security.