|
Website by Michael Horowitz 
|
|
Website by Michael Horowitz
|
 |
Multiple copies of Java can be installed on a single computer, and, if you have more than one
web browser, each one can use a different version of Java, or none at all, so be sure to test
them all. Below are nine ways to determine the version of Java a web browser is using.
Note: The portion of Java that runs programs is referred to as the Java
Virtual Machine (JVM) or Java Run-time Environment (JRE).
This is my favorite - straight from the horse's mouth (so to speak). The Java Run-time Environment is aware of its version and the company that authored it. So I wrote a very simple applet (the source code is on the About page) that gets this information from the JRE and displays it in a pink rectangle.
| The version and vendor from the JRE |
|
If Java is working, you will see a pink rectangle above with one line of text that says something like:
Java Version 1.5.0_12 from Sun Microsystems Inc. or |
If you don't see a pink rectangle above, Java may not be installed. Or ZoneAlarm may be blocking the Java applet/program that displays the pink rectangle. Zone Alarm has a Mobile Code Control feature that, if set to "Custom", requires you to first enable mobile code from this web site (www.javatester.org). In addition, your web browser may have Java disabled. See sample results.
| RECENT JAVA VERSIONS |
| Version 1.6.x. |
|
| Version 1.5.x |
|
Since, for all practical purposes Sun Microsystems owns Java, you'd think they would tell you the latest version. But, like any large organization it seems as if the left hand does not know what the right hand is doing. They have multiple Java Testers and neither has reliably reported the latest version (for more see the Other Testers page). This dedicated Java download page has also been offering old versions (in October 2006, it was three releases back, though in March 2007 it was current). Then again according to this posting at Ed Foster's GripeLog: Sun Never Sets on Java Security Updates, the situation is even worse with Sun withdrawing new versions for being buggy all the time.
The most reliable page from Sun for downloading the latest version of Java is java.sun.com/javase/downloads/index.jsp. The intended audience for this page however is computer nerds, so don't expect to understand most of it. Look for the "Java Runtime Environment (JRE)" download.
In Windows, open a DOS prompt (a.k.a command window) and enter the following command
java -version
The output will look something like:
java version "1.6.0_03"
Java(TM) SE Runtime Environment (build 1.6.0_03-b05)
Java HotSpot(TM) Client VM (build 1.6.0_03-b05, mixed mode, sharing)
You can also use the command "java -fullversion" and produce output such as:
java full version "1.6.0_03-b05"
On a computer without any version of Java from Sun Microsystems installed, this results in an error message:
'java' is not recognized as an internal or external command, operable program or batch file.
A computer with only Microsoft's ancient version of Java installed, also produces the above error.
On a Windows machine with multiple versions of Java, according to Sun, this command returns the default JVM.
For the Microsoft JVM, you can get information from the jview command when entered at a DOS prompt. If you receive an error that no program by that name exists, then there is no Microsoft JVM on your computer. If output is displayed, the first line will look something like this:
Microsoft (R) Command-line Loader for Java Version 5.00.3802
Microsoft confuses things in that there are two "versions" at play here. The jview command displays the version of the Microsoft JVM which is independent of the version of Java that it implements (1.1.4). Microsoft may upgrade their JVM to fix bugs in the future, and this may result in a new version of their JVM, but it will still implement the ancient Java version 1.1.4.
Versions of the Microsoft JVM are identified by build numbers. The first line of the jview output has a version number in x.yy.zzzz format. The final four digits (zzzz) are the version number. On a fairly untouched Windows 98 SE machine, the version was 5.00.3167. As of November 2002, the latest version of the Microsoft JVM was 5.00.3805 (see Scot Finnie's newsletter, October 11, 2002). By December 2002, the latest version was 5.00.3809. As of April 2003, the latest version is 5.0.3810 and, as of July 2005, the latest version is still 3810. Microsoft Knowledge Base Article - 163637 INFO: Availability of Current Build of Microsoft VM has more on using the jview command.
Even if Microsoft's JVM is installed on your computer, your web browser may use a different JVM. Sun Microsystems describes another way to test for the presence of the Microsoft JVM. See How do I uninstall Microsoft Virtual Machine?
In the Firefox address bar, enter:
about:plugins
If Java is installed there will be multiple entries labeled either "Java (TM) Platform" or "Java Plug-in" (last verified with Firefox 2.0.0.12).
On a Windows XP machine with Java version 1.6.0_03 installed, there were seven Java entries, all labelled "Java(TM) Platform SE 6 U3" which translates to version 6, update 3. According to Sun "Java(TM) Plug-in 1.5.0_11-b03" translates to version 1.5.0_11.
Back with version 1 of Firefox, the many Java entries showed different versions of Java. For more on how this used to work, see Multi-Version Support from Sun.
I haven't tested with the Mozilla browser in a long time. It used to be that you did Help -> About Plug-ins. If Java was not installed, this showed nothing. However, when Java was installed it showed seven different Java plug-in entries. Somewhere in these seven entries was the version of Java used by Mozilla.
Java from Sun Microsystems
If a version of Sun's Java is installed, then do: Tools => Sun Java Console. In both IE6 and IE7 this opens a new window (see below). The first two lines of the window display the version of Sun's Java. The terms used are "plug-in" and "JRE". Translate these to "Java".
Java Plug-in 1.6.0_03
Using JRE version 1.6.0_03 Java HotSpot(TM) Client VM
Currently Used JVM
In Internet Explorer 6 and 7 do: Tools => Internet Options => Advanced tab and scroll down to about the middle of the options list.
If Microsoft's Java is installed, there will be a section in this list called "Microsoft VM". If a Sun version of Java is installed, there will be a section in this list called "Java (Sun)". If you see both, then IE is using the one that is checked.
ActiveX Control/ProgramAnother IE specific approach is to check the version of the ActiveX control/program that implements Java.
Using Internet Explorer v6 do:
Tools => Internet Options => General tab
=> Settings button => View Objects button
This takes you to the folder where the ActiveX controls live:
C:\Windows\Downloaded Program Files
But, at this point it gets messy. As shown above, in April 2007 on a machine running Windows XP SP2 with all patches applied, there were three, seemingly identical, copies of Java.
The installed version of Java on this machine was 1.5.0_10. Yet the version number displayed here was 5,0,100,3. Beats me. You can right click on an ActiveX control and get the properties. Each one showed that it was the Java Plugin 1.5.0_10. So why three? Worse still, each one said it was "for Netscape Navigator (DLL" but Netscape Navigator was never installed on this machine. Screen shot of the properties
If the Java coffee cup is displayed in the System Tray (a.k.a Notification area) you can right click on it, select "About Java Technology" and get a display that looks like the one shown here.
You can tell which, if any, versions of Sun's Java are installed using the Windows Control Panel. Note however, that just because Sun's Java is installed, does not mean that any particular web browser on your computer is using it. In the Control Panel, select Add/Remove Programs. What to look for in this list of installed programs varies.
In the old days such as Sun's Java version 1.4.2, the entry here looked like "Java 2 Runtime Environment, SE v1.4.2._06". This
meant that
version 1.4.2_06 is installed on the computer. I hadn't checked this in a
long time and it has changed for the worse. With Sun's Java version 1.5.0, look
for an entry like
"J2SE Runtime Environment
5.0 Update 6"
Leave it to Sun to confuse this as much as possible. I'll translate:
So, in English it means Sun's Java version 1.5.0_06
In some flavors of Windows, the System Information utility includes information about Internet Explorer. Among the data displayed is information on the Java Virtual Machine.
In Windows 2000 you run the System Information utility with:
Start -> Programs -> Accessories -> System
Tools -> System Information
Double Click on Internet Explorer in the left hand column, then click on Summary. The Java VM version is displayed. It is similar to the output from the jview command, but not exactly the same. On one computer jview displayed 5.00.3809 while the System Information utility displayed 5.0.3809.0.
The path to the System Information utility is the same in Windows XP as in Windows 2000. However, XP does not display Java version information (at least XP Home Edition SP1 does not).
In Windows 98SE, the path to the System Information utility is also the same as with Windows 2000. I ran it on two Windows 98SE machines. With a recent version of IE5, System Information included Internet Explorer information. With an old version of IE (5.00.2614.3500) it did not.
For Internet Explorer v6 using Sun's Java:
Enable the Java console with Tools => Sun Java Console. When the Java Console pops up, the version number is at the top.
A recent example:
Java Plug-in 1.5.0_10
Using JRE version 1.5.0_10 Java HotSpot(TM) Client VM
User home directory = C:\Documents and
Settings\youruserid
An old example:
Java(TM) Plug-in: Version 1.4.2_04
Using JRE version 1.4.2_04 Java HotSpot(TM) Client VM
Additional details, such as the Home Directory where the JVM is installed, are provided by typing "S" for System Properties.
When IE5 and IE6 are using Microsoft's Java, you can add the Java console to the View menu by:
Tools =>
Internet Options => Advanced tab => Scroll down to the Microsoft VM section
Then turn on the
checkbox for Java console enabled.
Enabling the Java console requires a restart of IE, not of Windows.
After enabling the Java console, select View => Java Console. This opens a new window, the first line of which, has information on the JVM version. This appears to be the same information reported by the jview command. Note however that the Java Console will also appear as an option when you select "View" in Windows Explorer.
On a machine running IE 6 with all patches applied as of December 2003 under Windows 2000 the output was:
On a machine running IE 5.5 SP2 under Windows 2000, the output was:
On a machine running IE 5.01 SP2 under Windows NT4 the output was:
In Mozilla 1.6, you enable the Java console with Tools => Web development => Java Console. If there is no Java Console option, then Java is not installed in your copy of Mozilla. When you turn on the Java Console, it displays the Java version at the top.
Netscape Navigator 4.x can also display the Java console. Click on
"Communicator", then "Tools", then "Java Console".
The first line of the Java console window identifies the vendor and version of
the JVM. Navigator 4.72, 4.78 and 4.8 said:
Netscape
Communications Corporation -- Java 1.1.5
This works however, only if Java is enabled. With Java disabled, a console
window is not opened.
The Other Testers page list other Java
Testers in addition to testers for Flash, QuickTime, and more.
