Article ID: 177168
Article Last Modified on 11/14/2005
APPLIES TO
- Microsoft Internet Explorer 4.01 128-Bit Edition
- Microsoft Internet Explorer 4.0 128-Bit Edition
- Microsoft Internet Explorer 4.01 128-Bit Edition
- Microsoft Internet Explorer 4.0 128-Bit Edition
- Microsoft Java Virtual Machine
- Microsoft Software Development Kit for Java 2.02
- Microsoft Software Development Kit for Java 2.01
- Microsoft Software Development Kit for Java 2.02
- Microsoft Software Development Kit for Java 3.0
- Microsoft Software Development Kit for Java 3.1
This article was previously published under Q177168
SUMMARY
This article talks about how the Microsoft virtual machine (Microsoft VM) searches for a class on the local machine and Web site.
MORE INFORMATION
When a class is requested, the Microsoft VM normally searches for it in the following order:
- Check all explicitly specified locations (typically supplied with the jview /cp command-line option, not applicable for applets).
- Check the locations specified in the HKLM\Software\Microsoft\Java VM\DevClasspath registry entry.
NOTE: this registry entry is provided for development and testing, and may not be supported in a future release. Microsoft does not recommend relying on it for production purposes.
- Search packages in the Java Package Manager (JPM) marked as system (see notes below) packages.
- Check the locations specified in the HKLM\Software\Microsoft\Java VM\TrustedClasspath registry entry.
- Check the directory specified by the HKLM\Software\Microsoft\Java VM\TrustedLibsDirectory registry entry.
- Check the locations specified in the HKLM\Software\Microsoft\Java VM\Classpath registry entry.
- Check the directory specified by the HKLM\Software\Microsoft\Java VM\LibsDirectory registry entry.
- Check the locations specified in the CLASSPATH environment variable.
- Search packages in the JPM marked as non-system (see notes below) packages. Searching first for non-system classes in the specified namespace, then searching for non-system classes in no namespace (global namespace).
- If served from a Web page, the Microsoft VM additionally searches the following locations:
- Any cabinet files referenced by the Cabinets applet parameter (in the order in which they appear in the HTML). If there is a Cabinets applet parameter, the Cabbase parameter and the Archive attribute (below) will not be searched.
- The cabinet file referenced by the Cabbase applet parameter. If there is a Cabbase applet parameter, the Archive attribute (below) will not be searched.
- Any zip or jar file referenced by the 'archive' attribute of the applet tag.
- Search the code base of the HTML.
Notes
- The contents of the registry values for items 2, 4, and 6 and the environment variable in item 8 should contain a semi-colon-delimited list of directories, zip files, and/or jar files. Multiple entries will be searched in the order they appear. The registry values for items 5 and 7 may only specify a single directory.
- The Java Package Manager (JPM) is a service used by the Microsoft VM to store and retrieve Java classes.
- Classes loaded by steps 1-8 above are considered system classes. Classes loaded by steps 9-11 are considered non-system classes. Non-system classes are not loaded by the system class loader, but instead are loaded by an instance of a Java ClassLoader. Non-system classes are not global and will not interact with other non-system classes loaded by a different ClassLoader. All the standard packages installed with the Microsoft VM are system packages.
- When a class is loaded by an untrusted caller from one of the specified locations and it is only safe for use by a trusted caller, an exception may occur when trying to call a method or access a member of the class.
Here are the requirements for a package installed into the JPM to be considered as system packages:
- Must reside in the global namespace.
- Must be signed with full permissions.
- The .osd inside the installation CAB must specify the <SYSTEM/> tag for each package. If using the DUBUILD tool to create the CAB file, use the /S command line switch to specify system packages.
REFERENCES
Further information about the Java Package Manager can be found at the following Web site:
For the latest Knowledge Base articles and other support information on Visual J++ and the SDK for Java, see the following pages on the Microsoft Technical Support site:
Additional query words: search order class jpm
Keywords: kbinfo KB177168
