Java Development Environment Release Notes

In addition to the information here, see our demos.

Since this release is based on Sun's 1.1.6 JDK release, it in general contains the same known bugs. Likewise, all the bugs fixed by Sun's JDK releases through 1.1.6 have been fixed in this release with respect to our previous releases, version 3.0.1 (based on Sun's 1.1.3) and version 3.1 (based on Sun's 1.1.5). For details, see Sun's Java Bugs Web Site.

One exception is that this release includes a patch which fixes Sun bug 4134300, a bug in the string formatting of the java.text.DecimalFormat class. This fix is not in Sun's 1.1.6 release, but will be in their 1.1.7 release.

General Release Notes

• The javadoc program automatically creates HTML documentation for Java classes from the source code. The HTML files that it creates make use of various decorative images; these can be found in the /usr/java/images directory.
  
  
• A bug existed in previous releases where using one of the family of exec() methods in the java.lang.Runtime class with an incorrect path or the name of a non-executable file would produce a core file. This bug has been fixed.

Native Code Development Release Notes

See our Native Code documentation for an introduction to working with native code.

• A bug existed in previous releases where accessing the fields of a Java object from both Java code and C/C++ code (i.e., native methods) using the old native method interface did not work sometimes because the layouts of object member fields decided upon by the Java interpreter and by the C/C++ compiler (from the header file generated by javah) were not guaranteed to be identical. This bug has been fixed.
  
  
• If you call functions in X/Motif, OpenGL, etc., from native code, you will need to perform locking around those calls, since these libraries are not thread-safe in general. To do so, first include the file monitor.h in your source files:

  #include <monitor.h>
  

  This header file in /usr/java/include defines the following two routines:

  void awt_lock_enter(void);
  void awt_lock_exit(void);
  

  which you should use to "wrap" your calls into these libraries:

  awt_lock_enter();
  ...
  awt_lock_exit();
  

  For an example, see our demos.

jdb Release Notes

• To evaluate a variable in your Java program:
  
  
  • you must have compiled the Java source file with the -g option to javac, and
    
    
  • if evaluation of a local variable is required, the current thread must be stopped at a point where the variable is live; in other words, the variable must have been given a value, and there must be a possibility that that value will be used before it is changed.
  
  Unless both of these are true, you will get the message "<not in scope>".
  
  
• Currently, you can only evaluate symbols (for example, print xyz or print this.abc). You cannot evaluate expressions.
  
  
• It is not possible to print the elements of multidimensional arrays.
  
  
• If you use the "up" and "down" commands to move around in the call stack of a suspended thread, the "step", "next", and "return" commands will no longer operate with respect to the selected stack frame as they have in previous releases; they now always operate with respect to the last frame in the call stack.
  
  
• When running under jdb, it is not possible to set breakpoints in native methods.
  
  
• When debugging an applet, using the "Restart" item in the appletviewer's menu may cause some applets to function incorrectly. If you encounter this problem using jdb, you must quit and restart jdb instead.

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