Mac OS Related IssuesIM:JM

Inside Macintosh: JManager Reference /

Appendix A - Mac OS Related Issues
The Mac OS runtime environment has some restrictions and peculiarities that you should keep in mind when writing either Java code or Mac OS-based code that interacts with Java code. Table A-1 describes these issues and possible solutions.

Table A-1 Mac OS related issues
Description Possible Limitations Solutions
31-character limit on filenames. Java class filenames can easily exceed 31 characters. Class files stored in zip files can have names longer than 31 characters.
One menu bar allowed per active frame. Some Java programs may specify more than one menu per frame.
Cooperative rather than preemptive multitasking. Some odd timing effects may occur.
Mac OS users may not use virtual memory, and those who do have it locked into a particular fixed size. Garbage collection and performance may be affected.
File and directory delimeter character is a colon (:), not a slash (/). (The slash is a valid character). May cause confusion or odd behavior when working with file systems that return a URL or similar path (such as not finding a file located in a folder named Reports May/June).
A space is a valid character. May cause unexpected interpretations of strings obtained from other platforms.

The mechanism for handling dynamically-linked libraries (DLLs) on the Mac OS platform is the Code Fragment Manager (CFM). For information about the Code Fragment Manager, see Mac OS Runtime Architectures and Inside Macintosh: PowerPC System Software.
In addition, the standards for the Mac OS user interface are often different from those on other platforms. A few things to keep in mind are as follows:

The Preferences menu item is typically stored under the Edit Menu (not the File menu).
Dialog boxes typically have the OK button located near the lower right corner, with the Cancel button to its immediate left.
The default grayscale appearance of windows and menus in System 7.6 and later is lighter than the corresponding Windows 95 appearance.

**Table A-1 Mac OS related issues**
Description	Possible Limitations	Solutions
31-character limit on filenames.	Java class filenames can easily exceed 31 characters.	Class files stored in zip files can have names longer than 31 characters.
One menu bar allowed per active frame.	Some Java programs may specify more than one menu per frame.
Cooperative rather than preemptive multitasking.	Some odd timing effects may occur.
Mac OS users may not use virtual memory, and those who do have it locked into a particular fixed size.	Garbage collection and performance may be affected.
File and directory delimeter character is a colon (`:`), not a slash (`/`). (The slash is a valid character).	May cause confusion or odd behavior when working with file systems that return a URL or similar path (such as not finding a file located in a folder named `Reports May/June`).
A space is a valid character.	May cause unexpected interpretations of strings obtained from other platforms.