NonStop Server for Java 5.0 Programmer's Reference

Java linker flag
Tandem
float
Tandem
float
IEEE
float
IEEE
float
Since NonStop Server for Java 3.1.x and earlier set the linker flag for the process to TNS float,
any use of the C runtime library used routines that handled TNS floats. For NonStop Server for
Java 4 and 5 versions, the linker flags described under Linker and Compiler Options are used to
specify IEEE floating point. Accordingly, the C runtime library uses routines that handle IEEE
floating point.
For NonStop Server for Java 4 and 5 versions, any C runtime library calls such as sprintf or
sscanf, made from JNI code, assumes IEEE float values and calling conventions. For
example, assume that JNI code, written for a previous version of Java, converts a TNS
floating-point value to a string, which is then passed to Java. To migrate the program, you must
change the JNI code to convert the TNS floating-point value to an IEEE floating-point value
and then call sprintf to convert the floating-point value to a string.
For more information, see IEEE Floating-Point Implementation.
Using AWT Classes
If your Java programs use AWT classes with NonStop Server for Java 3.1.x or earlier versions,
change your program code to catch a HeadlessException rather than an
UnsupportedClassException.
Because the NonStop operating system does not provide support for windowing operations,
previous versions of NonStop Server for Java supported only those Abstract Windowing
Toolkit (AWT) classes and methods that did not require a display, keyboard, sound, or mouse
operation. Any class or method that required such an operation threw an
UnsupportedClassException.
NonStop Server for Java 4 supports the Sun Microsystems enhancement to AWT called
"headless support" that allows a JVM to indicate whether a display, keyboard, sound, or mouse
operation can be supported in a graphics environment.
Sun implemented headless support by supplying two new methods in the
GraphicsEnvironment class: isHeadless and isHeadlessInstance. In addition,
Sun created a new exception java.awt.HeadlessException. HeadlessException will be
thrown by any class or method that requires a display, keyboard, sound, or mouse operation if
such a class or method is invoked when GraphicsEnvironment.isHeadless returns
true. Classes and methods that support printing, fonts, and imaging are fully supported in a
headless JVM and are fully supported by NonStop Server for Java 4 and 5.
For further information, see Headless Support in the HP Implementation specifics section.