JRE and JDK with ArcIMS 4.0

Questions and Answers about using JRE and JDK with ArcIMS 4.0

Q: Which version of JRE does ArcIMS 4.0 use?
A: The following table summarizes the supported JRE for each platform:

Platform	Operating System	JRE version	Downloadable?
Windows	XP	JRE 1.3.1_02	Available from Sun archive.
Windows	2000 (with or without SP2)	JRE 1.3.1_02	Available from Sun archive.
Windows	NT 4.0 SP 6a	JRE 1.3.1_02	Available from Sun archive.
Sun	Solaris 7	JRE 1.3.1_02	Available from Sun archive.
Sun	Solaris 8	JRE 1.3.1_02	Available from Sun archive.
IBM	AIX 4.3.3 Maintenance Level 2 (4330-02)	JRE 1.3.0	Available from IBM site. Click "Register and Download" link.
Linux-Intel	Red Hat 7.1	JRE 1.3.1_02	Available from Sun archive.
HP	11.0-UX (64 bit)	JRE 1.3.1_01	Available from the HP site.
Windows	98 (client only)	JRE 1.3.1_02	Available from Sun archive.

Q: Can I use JRE 1.4.0 or JRE 1.4.0_01 with ArcIMS 4.0?
A: No. JRE 1.4.0 and JRE 1.4.0_01 are not supported. You will find that ArcIMS Java applications will not always work correctly. In addition, some of the panels and dialogs might be blank or have unformatted text. If you try to use JRE 1.4.0_01, the Java Plug-In used by ArcIMS Manager, Remote Manager, and the ArcIMS Java Viewers will not work. Use JRE 1.3.1_02 instead.

Q: Can I use JRE 1.3.1_03 or JRE 1.3.1_04?
A: No, JRE 1.3.1_03 and JRE 1.3.1_04 are not supported. If you use either of these versions, the Java Plug-In used by ArcIMS Manager, Remote Manager, and the ArcIMS Java Viewers will not work. Use JRE 1.3.1_02 instead.

Q: What is JRE?
A: Java Runtime Environment. JRE provides the core classes and files necessary for you to execute Java applications. The Java applications are made up of one or more Java ARchive (JAR) files or .class files. You cannot develop and compile Java applications using the runtime environment. ArcIMS Java applications requiring JRE include Author, Designer, and Administrator as well as ArcIMS Manager, Remote Manager, and the ArcIMS Java Viewers.

Q: What is JDK?
A: Java Development Kit, also called Java 2 Software Development Kit (SDK). JDK provides a development environment for Java applications. With JDK, you can compile Java class (.java) files to create JAR and .class files and can compile pages developed using JSP. When you install JDK, you also install JRE, which is a subset of JDK.

Q: What is J2SE?
A: J2SE is the specification for the Java Platform, Standard Edition. It consists of a standard API. JRE and Java 2 SDK (JDK) are used to implement the specification.

Q: Are there any ArcIMS applications that require JDK instead of JRE?
A: Yes. If you plan to use JSP with the Java Connector, your servlet engine must be JDK-enabled. ArcIMS components using the Java Connector are the ArcIMS Service Administrator, Metadata Explorer, and your own JSP applications. This version of JDK does not need to be the same version used when you install ArcIMS.

Q: Can I have multiple versions of JRE and JDK on my machine?
A: Yes, and each version is independent of other versions.

Q: I have applications on my machine that do not use the system JRE. How does this work?
A: Many Java applications use some sort of pointer to a specific version of JRE (or JDK) rather than the system JRE. For example, if you have Jakarta-Tomcat on your machine, one of the parameters in the Tomcat configuration file - workers.properties - is the location of the JavaHome directory.

Q: What's the difference between a system and private JRE?
A: The system JRE is the active version in the registry. All other versions of JRE or JDK on your machine are private versions.

Q: Why do the ArcIMS Java applications no longer work when I change to a different system JRE?
A: When ArcIMS is installed, some ArcIMS JAR files are placed in the current system JRE. When you change to another JRE, these JAR files are not part of the system JRE, and ArcIMS cannot locate them. You need to copy the JAR files located in the \lib\ext of your old system JRE to the same directory in the new system JRE.