Title: Method and apparatus for selecting classes using a browser for use by a virtual machine in a data processing system
Abstract: A method for selecting classes using a browser for use by a virtual machine in a data processing system. The browser provides an interface in which the interface allows for selection of classes for use by the virtual machine. A selection of classes is received through the interface. The selection of classes is stored by the browser, wherein the selection of classes is used by the browser when initializing the virtual machine.
Patent Number: 6,842,897 Issued on 01/11/2005 to Beadle, et al.
| Inventors:
|
Beadle; Bruce Anthony (Round Rock, TX);
Brown; Michael Wayne (Georgetown, TX);
Lawrence; Kelvin Roderick (Round Rock, TX);
Rothert; Douglas Scott (Austin, TX);
Russin; Robert Michael (Austin, TX)
|
| Assignee:
|
International Business Machines Corporation (Armonk, NY)
|
| Appl. No.:
|
127336 |
| Filed:
|
July 31, 1998 |
| Current U.S. Class: |
718/1; 717/121; 717/148 |
| Intern'l Class: |
G06F 009/00 |
| Field of Search: |
718/1
717/121,148,105,170
345/700
709/220,221,222,1
|
References Cited [Referenced By]
U.S. Patent Documents
| 5734831 | Mar., 1998 | Sanders | 709/223.
|
| 6205476 | Mar., 2001 | Hayes, Jr. | 709/220.
|
| 6263377 | Jul., 2001 | Monday et al. | 709/320.
|
| 6332218 | Dec., 2001 | Walker et al. | 717/166.
|
| 6339829 | Jan., 2002 | Beadle et al. | 713/201.
|
| 6433794 | Aug., 2002 | Beadle et al. | 345/700.
|
Other References
"Java Native Interface Specification," May 1997, JavaSoft, Release 1.1, p.
75-82.*
Michael Edwards, "More Sniffing for Browsers, Virtual Machines, and
Operating Systems," Jun. 1998, p. 1-4, obtained from website:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndetect/
html/sniffing.asp.
|
Primary Examiner: An; Meng-Al T.
Assistant Examiner: Zhen; Li
Attorney, Agent or Firm: Yee; Duke W., LaBaw; Jeffrey S., Bailey; Wayne P.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
The present invention is related to the following applications entitled
"Method and Apparatus to Selectively Define Java Virtual Machine
Initializing Properties Using a Browser Graphical User Interface", U.S.
Ser. No. 09/127,337, filed even date hereof, assigned to a common
assignee, and "Method and Apparatus for Selecting a Java Virtual Machine
For Use With a Browser", U.S. Ser. No. 09/127,339 (which issued as U.S.
Pat. No. 6,433,794 on Aug. 13, 2002), filed even date hereof, assigned to
a common assignee which are incorporated herein by reference.
Claims
What is claimed is:
1. A method for selecting classes using a browser for use by a virtual
machine in a data processing system, the method comprising:
providing through the browser, an interface in which the interface allows
for selection of classes for use by the virtual machine;
receiving a selection of classes through the interface;
storing the selection of classes, wherein the selection of classes is used
by the browser when initializing the virtual machine; and
using the selection of the classes to initialize the virtual machine.
2. The method of claim 1, wherein the interface is a graphical user
interface.
3. The method of claim 1, wherein the virtual machine is a Java virtual
machine.
4. The method of claim 1, wherein the step of storing the selection of
classes comprises storing the selection of classes in a user profile.
5. The method of claim 1, wherein the selection of classes is a class path.
6. The method of claim 1, wherein the selection of classes causes a class
path to be appended to a system class path.
7. A method for selecting classes for use by a Java virtual machine
associated with a browser, the method comprising:
displaying a graphical user interface in which a classpath may be selected
to define classes for use with the Java virtual machine;
receiving a selection of the classpath from the graphical user interface;
storing the selection of the classpath; and
initializing the Java virtual machine using the selection of the class
path.
8. The method of claim 7, wherein the selection of the classpath appends
the classpath to a system classpath.
9. The method of claim 8, wherein the system class path has an end and
wherein the classpath is appended to the end of the system classpath.
10. The method of claim 8, wherein the system classpath has a beginning and
wherein the classpath is appended to a beginning of the system classpath.
11. A data processing system for selecting classes using a browser for use
by a virtual machine in the data processing system, the data processing
system comprising:
providing means for providing through the browser an interface in which the
interface allows for selection of classes for use by the virtual machine;
receiving means for receiving a selection of classes through the interface;
storing means for storing the selection of classes, wherein the selection
of classes is used by the browser when initializing the virtual machine;
and
means for using the selection of the classes to initialize the virtual
machine.
12. The data processing system of claim 11, wherein the interface is a
graphical user interface.
13. The data processing system of claim 11, wherein the virtual machine is
a Java virtual machine.
14. The data processing system of claim 11, wherein the step of storing the
election of classes comprises storing the selection of classes in a user
profile.
15. The data processing system of claim 11, wherein the selection of
classes is a classpath.
16. The data processing system of claim 11, wherein the selection of
classes causes a classpath to be appended to a system class path.
17. A computer program product in a computer readable medium for selecting
classes for use by a Java virtual machine associated with a browser, the
computer program product comprising:
first instructions for displaying a graphical user interface in which a
classpath may be selected to define classes for use with the Java virtual
machine;
second instructions for receiving a selection of the classpath from the
graphical user interface;
third instructions for storing the selection of the classpath; and
fourth instructions for initializing the Java virtual machine using the
selection of the classpath.
18. A method for selecting a class for use by a virtual machine in a data
processing system, the method comprising:
providing through a browser, an interface in which the interface allows for
selection of a class location for use by the virtual machine;
receiving a selection of a class location through the interface;
storing the class location, wherein the class location is used by the
browser to load a class when initializing the virtual machine; and
using the selection of the class to initialize the virtual machine.
19. The method of claim 18, wherein the class location is a class path.
20. The method of claim 18, wherein the class location is stored in a user
profile data structure.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention provides an improved data processing system and in
particular an improved method and apparatus for selecting properties for a
JVM. Still more particularly, the present invention provides a method and
apparatus for selecting classes for a JVM used with a browser.
2. Description of Related Art
Internet, also referred to as an "internetwork", in communications is a set
of computer networks, possibly dissimilar, joined together by means of
gateways that handle data transfer and the conversion of messages from the
sending network to the protocols used by the receiving network (with
packets if necessary). When capitalized, the term "Internet" refers to the
collection of networks and gateways that use the TCP/IP suite of
protocols.
The Internet has become a cultural fixture as a source of both information
and entertainment. Many businesses are creating Internet sites as an
integral part of their marketing efforts, informing consumers of the
products or services offered by the business or providing other
information seeking to engender brand loyalty. Many federal, state, and
local government agencies are also employing Internet sites for
informational purposes, particularly agencies which must interact with
virtually all segments of society such as the Internal Revenue Service and
secretaries of state. Operating costs may be reduced by providing
informational guides and/or searchable databases of public records online.
Currently, the most commonly employed method of transferring data over the
Internet is to employ the World Wide Web environment, also called simply
"the web". Other Internet resources exist for transferring information,
such as File Transfer Protocol (FTP) and Gopher, but have not achieved the
popularity of the web. In the web environment, servers and clients effect
data transaction using the Hypertext Transfer Protocol (HTTP), a known
protocol for handling the transfer of various data files (e.g., text,
still graphic images, audio, motion video, etc.). Information is formatted
for presentation to a user by a standard page description language, the
Hypertext Markup Language (HTML). In addition to basic presentation
formatting, HTML allows developers to specify "links" to other web
resources identified by a Uniform Resource Locator (URL). A URL is a
special syntax identifier defining a communications path to specific
information. Each logical block of information accessible to a client,
called a "page" or a "web page", is identified by a URL. The URL provides
a universal, consistent method for finding and accessing this information
by the web "browser". A browser is a program capable of submitting a
request for information identified by a URL at the client machine.
Retrieval of information on the web is generally accomplished with an
HTML-compatible browser.
When a user desires to retrieve a page, a request is submitted to a server
connected to a client computer at which the user is located and may be
handled by a series of servers to effect retrieval of the requested
information. The information is provided to the client formatted according
to HTML. Typically, personal computers (PCs) along with work stations are
typically used to access the Internet.
Often applications or programs may be sent to a computer from a web server
across the Internet. Java applications are becoming increasingly more
prevalent as the type of application sent between web servers and client
computers. Java applications are common on the Internet and becoming more
increasingly common in intranets and in other types of networks used in
businesses.
Java is an object oriented programming language and environment focusing on
defining data as objects and the methods that may be applied to those
objects. Java supports only a single inheritance, meaning that each class
can inherit from only one other class at any given time. Java also allows
for the creation of totally abstract classes known as interfaces, which
allow the defining of methods that may be shared with several classes
without regard for how other classes are handling the methods.
The Java virtual machine (JVM) is a virtual computer component that resides
only in memory. The JVM allows Java programs to be executed on a different
platform as opposed to only the one platform for which the code was
compiled. Java programs are compiled for the JVM. In this manner, Java is
able to support applications for many types of data processing systems,
which may contain a variety of central processing units and operating
systems architectures. To enable a Java application to execute on
different types of data processing systems, a compiler typically generates
an architecture-neutral file format--the compiled code is executable on
many processors, given the presence of the Java run-time system. The Java
compiler generates bytecode instructions that are non-specific to a
particular computer architecture. A bytecode is a machine independent code
generated by the Java compiler and executed by a Java interpreter. A Java
interpreter is a part in the JVM that alternately decodes and interprets a
bytecode or bytecodes. These bytecode instructions are designed to be easy
to interpret on any computer and easily translated on the fly into native
machine code.
Presently available browsers are designed with a notion of a fixed JVM,
which uses a fixed value for the Java classpath. No flexible mechanisms
are presently available for modifying or viewing the classpath within a
browser. The problem with this approach is that of the global nature of
the changing system classpath requires the user to modify the system
defined global classpath variable manually or via a script which is
executed prior to executing the browser. This system classpath variable is
shared with other non-Java browser related applets or applications in
addition to the Java enabled browser. Another problem exists for browsers
that provide for a multi-user environment in which multiple users/user
profiles are being employed. In such a situation, each user profile is
forced to use the same environment.
Therefore, it would be advantageous to have an improved method and
apparatus for providing users an ability to use more recent versions of
JVMs without having to wait for an updated version of the web browser.
SUMMARY OF THE INVENTION
The present invention provides a method for selecting classes using a
browser for use by a virtual machine in a data processing system. The
browser provides an interface in which the interface allows for selection
of classes for use by the virtual machine. A selection of classes is
received through the interface. The selection of classes is stored by the
browser, wherein the selection of classes is used by the browser when
initializing the virtual machine.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth
in the appended claims. The invention itself, however, as well as a
preferred mode of use, further objectives and advantages thereof, will
best be understood by reference to the following detailed description of
an illustrative embodiment when read in conjunction with the accompanying
drawings, wherein:
FIG. 1 is a pictorial representation of a distributed data processing
system in which the present invention may be implemented;
FIG. 2 is a block diagram of a data processing system which may be
implemented as a server in accordance to the present invention;
FIG. 3 is a block diagram of a data processing system in which the present
invention may be implemented;
FIG. 4 is a diagram of components used to select classpath value in
accordance with a preferred embodiment of the present invention;
FIG. 5 is a graphical user interface used in modifying classpath values in
accordance with a preferred embodiment of the present invention;
FIG. 6 is a diagram of a user profile data structure managed by a user
profile manager in accordance with a preferred embodiment of the present
invention;
FIG. 7 is a high level flowchart of a process used to select a JVM for use
with a web browser in accordance with a preferred embodiment of the
present invention;
FIG. 8 is a flowchart of a process for starting a JVM using classpath
values in accordance with a preferred embodiment of the present invention;
and
FIG. 9 is a diagram of a JVM initialization data structure in accordance
with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures, and in particular with reference to FIG.
1, a pictorial representation of a distributed data processing system in
which the present invention may be implemented is depicted.
Distributed data processing system 100 is a network of computers in which
the present invention may be implemented. Distributed data processing
system 100 contains a network 102, which is the medium used to provide
communications links between various devices and computers connected
together within distributed data processing system 100. Network 102 may
include permanent connections, such as wire or fiber optic cables, or
temporary connections made through telephone connections.
In the depicted example, a server 104 is connected to network 102 along
with storage unit 106. In addition, clients 108, 110, and 112 also are
connected to a network 102. These clients 108, 110, and 112 may be, for
example, personal computers or network computers. For purposes of this
application, a network computer is any computer, coupled to a network,
which receives a program or other application from another computer
coupled to the network. In the depicted example, server 104 provides data,
such as boot files, operating system images, and applications to clients
108-112. Clients 108, 110, and 112 are clients to server 104. Distributed
data processing system 100 may include additional servers, clients, and
other devices not shown. In the depicted example, distributed data
processing system 100 is the Internet with network 102 representing a
worldwide collection of networks and gateways that use the TCP/IP suite of
protocols to communicate with one another. At the heart of the Internet is
a backbone of high-speed data communication lines between major nodes or
host computers, consisting of thousands of commercial, government,
educational, and other computer systems, that route data and messages. Of
course, distributed data processing system 100 also may be implemented as
an umber of different types of networks, such as for example, an intranet
or a local area network.
FIG. 1 is intended as an example, and not as an architectural limitation
for the processes of the present invention.
Referring to FIG. 2, a block diagram of a data processing system which may
be implemented as a server, such as server 104 in FIG. 1, is depicted in
accordance to the present invention. Data processing system 200 may be a
symmetric multiprocessor (SMP) system including a plurality of processors
202 and 204 connected to system bus 206. Alternatively, a single processor
system may be employed. Also connected to system bus 206 is memory
controller/cache 208, which provides an interface to local memory 209. I/O
bus bridge 210 is connected to system bus 206 and provides an interface to
I/O bus 212. Memory controller/cache 208 and I/O bus bridge 210 may be
integrated as depicted.
Peripheral component interconnect (PCI) bus bridge 214 connected to I/O bus
212 provides an interface to PCI local bus 216. A number of modems 218-220
may be connected to PCI bus 216. Typical PCI bus implementations will
support four PCI expansion slots or add-in connectors. Communications
links to network computers 108-112 in FIG. 1 may be provided through modem
218 and network adapter 220 connected to PCI local bus 216 through add-in
boards.
Additional PCI bus bridges 222 and 224 provide interfaces for additional
PCI buses 226 and 228, from which additional modems or network adapters
may be supported. In this manner, server 200 allows connections to
multiple network computers. A memory mapped graphics adapter 230 and hard
disk 232 may also be connected to I/O bus 212 as depicted, either directly
or indirectly.
Those of ordinary skill in the art will appreciate that the hardware
depicted in FIG. 2 may vary. For example, other peripheral devices, such
as optical disk drive and the like also may be used in addition or in
place of the hardware depicted. The depicted example is not meant to imply
architectural limitations with respect to the present invention.
The data processing system depicted in FIG. 2 may be, for example, an IBM
RISC/System 6000 system, a product of International Business Machines
Corporation in Armonk, N.Y., running the Advanced Interactive Executive
(AIX) operating system.
With reference now to FIG. 3, a block diagram of a data processing system
in which the present invention may be implemented is illustrated. Data
processing system 300 is an example of a client computer. Data processing
system 300 employs a peripheral component interconnect (PCI) local bus
architecture. Although the depicted example employs a PCI bus, other bus
architectures such as Micro Channel and ISA may be used. Processor 302 and
main memory 304 are connected to PCI local bus 306 through PCI bridge 308.
PCI bridge 308 also may include an integrated memory controller and cache
memory for processor 302. Additional connections to PCI local bus 306 may
be made through direct component interconnection or through add-in boards.
In the depicted example, local area network (LAN) adapter 310, SCSI host
bus adapter 312, and expansion bus interface 314 are connected to PCI
local bus 306 by direct component connection. In contrast, audio adapter
316, graphics adapter 318, and audio/video adapter (A/V) 319 are connected
to PCI local bus 306 by add-in boards inserted into expansion slots.
Expansion bus interface 314 provides a connection for a keyboard and mouse
adapter 320, modem 322, and additional memory 324. SCSI host bus adapter
112 provides a connection for hard disk drive 326, tape drive 328, and
CD-ROM 330 in the depicted example. Typical PCI local bus implementations
will support three or four PCI expansion slots or add-in connectors.
An operating system runs on processor 302 and is used to coordinate and
provide control of various components within data processing system 300 in
FIG. 1. The operating system may be a commercially available operating
system such as OS/2, which is available from International Business
Machines Corporation. "OS/2" is a trademark of from International Business
Machines Corporation. An object oriented programming system such as Java
may run in conjunction with the operating system and provides calls to the
operating system from Java programs or applications executing on data
processing system 300. Instructions for the operating system, the
object-oriented operating system, and applications or programs are located
on storage devices, such as hard disk drive 326 and may be loaded into
main memory 304 for execution by processor 302.
Those of ordinary skill in the art will appreciate that the hardware in
FIG. 3 may vary depending on the implementation. For example, other
peripheral devices, such as optical disk drives and the like may be used
in addition to or in place of the hardware depicted in FIG. 3. The
depicted example is not meant to imply architectural limitations with
respect to the present invention. For example, the processes of the
present invention may be applied to multiprocessor data processing system.
The present invention provides a method, apparatus, and instructions for
selectively and dynamically loading classes. This mechanism also enables
and enhances polymorphism in an otherwise static Java classpath name
space. The present invention provides a mechanism for modifying or viewing
the value of a class path for a JVM that is used with a browser. Currently
available mechanisms for modifying the classpath variable for loading
needed classes rely on the user modifying the system defined global class
path manually or via a script executed prior to running the browser. The
classpath variable is an environmental variable that defines a path to the
"classes.zip" file, which is used to load classes for use by the JVM. The
present invention provides a high level of integration, which provides
users with maximum flexibility in setting the value for a classpath for
individual and multiple user environments. Different user profiles may
employ different classpaths such that switching of classpaths may be
accomplished by selection of a user profile. A graphical user interface
(GUI) is provided as part of the browser to allow a user to specify a
classpath, also referred to as an "extended classpath". This extended
classpath when set within the GUI provides the ability to assign a browser
a localized instance per user profile of a classpath. In the depicted
examples, a user may choose to append the extended classpath to the
beginning or end of the system defined classpath or simply ignore the
system defined classpath and only pass the extended classpath to JVM. By
changing or appending classpaths, the classes loaded and used in the JVM
may be changed. As used herein, the term "browser" refers to browsers in
addition to hypertext markup language (HTML) browsers, such as Netscape
Communicator for OS/2. In addition, a browser may encompass other
applications that operate in a Java based network or other distributed
network.
In the depicted examples, the processes and interfaces described are for a
browser, such as Netscape Communicator operating in an OS/2 operating
system. These examples are not intended to limit the invention to a
particular browser or operating system. The processes and interfaces of
the present invention may be applied to other types of browsers and
operating systems.
With reference now to FIG. 4, a diagram of components used to select
classpath value is depicted in accordance with a preferred embodiment of
the present invention. Internet browser 400 contains a user profile
manager 402, which is employed to manage one or more user profiles for
internet browser 400. Internet browser 400 may be implemented using a
browser, such as, for example, Netscape Communicator, which is available
from Netscape Communications Corporation. Selection module 404 contains
the processes used in providing a user an ability to select classpath
values. Selection module 404 presents a GUI 406 to the user, which allows
the user to select a value for the classpath that is to be employed for
the user when a JVM is initialized in association with the browser.
Selection module 404 queries user profile manager 402 within internet
browser 400 for user profile information to display to a user in setting a
classpath value. Selection module 404 queries application environment 408
for the system classpath. The application environment in the depicted
examples is the value of environmental variables before starting the
browser. In response, application environment 408 returns the system
classpath to selection module 404. This information is displayed to the
user through the GUI 406. Selections or changes in JVMs are received as
user input through GUI 406. This user input is returned to user profile
manager 402 when a JVM is to be started by internet browser 400, the user
profile information with the classpath value is employed to start JVM 410.
With reference next to FIG. 5, a graphical user interface used in modifying
classpath values is depicted in accordance with a preferred embodiment of
the present invention. Java advanced properties dialog 500 is displayed to
a user to allow for modification of various options for using a JVM with a
browser. Optional classpath field 502 is present in Java advanced
properties dialog 500 to allow a user to enter a classpath. The user then
may select a number of options 504, 506, and 508. Option 504 is selected
if the user desires to ignore changes to the classpath. This option is the
one selected in the depicted example. Option 506 is selected if a user
desires to append the classpath to the beginning of the system classpath.
Option 508 is selected if a user desires to append the classpath to the
end of the system classpath. The current classpath is displayed to the
user in current classpath field 510 in Java advanced properties dialog
500. By selecting option 512, a user may choose to ignore the system
classpath and use only the classpath entered by the user. If the user is
satisfied with the changes within Java advanced properties dialog 500, the
user may select OK button 514. Cancel button 516 is selected if the user
does not want to use options changed in Java advanced properties dialog
500.
With reference now to FIG. 6, a diagram of a user profile data structure
managed by a user profile manager is depicted in accordance with a
preferred embodiment of the present invention. User profile data structure
600 contains information used to configure behavior of the web browser for
a particular user. In the depicted example, user profile data structure
600 includes a profile name 602, a Java class path 604, Java parameters
606, a Java path 608, and a Java class path option 610. Profile name 602
is used to uniquely identify the profile from other profiles when the
browser contains multiple user profiles. Java class path 604 is used to
identify the path in which classes are loaded for use by the JVM. Java
parameters 606 contain parameters used by a JVM when the browser
initializes or starts a JVM for use with the browser. These parameters may
include, for example, initial heap size, garbage collection information,
Java stack size, and reporting options for JVM information. Java path 608
includes the path and file name for the JVM that is to be used with the
browser. Java class path option 610 provides information that may be used
to depend an extended class path to the beginning or end of the system
defined class path. User profile data structure 600 also includes other
information (not shown) employed to define the behavior of the browser.
With reference now to FIG. 7, a high level flowchart of a process used to
select a JVM for use with a web browser is depicted in accordance with a
preferred embodiment of the present invention. The process begins by
obtaining user profile data (step 700). This data is obtained from the
user profile manager within the browser. Next, the system classpath is
obtained from the application environment (step 702). The data is
displayed to a user using a GUI (step 704). A determination is then made
as to whether the classpath is to be changed (step 706). For example, this
step may be used to change the value for the Java classpath that is used
to load classes for use by the JVM, which is used with the browser. More
specifically in the depicted example, an extended classpath may be
appended to the beginning or end of the system classpath, or only the
extended classpath may be passed to the JVM.
If the classpath is not to be changed, the process terminates. Otherwise,
the new classpath is obtained (step 708). The new classpath is obtained
through a GUI presented to the user in which the user may select the
classpath for use by the JVM to be used with the browser. Thereafter, the
new settings for the classpath are written or sent to the profile manager
in the browser (step 710) with the process terminating thereafter. The
classpath may be, for example, OS2.ibm.java.classpath.
Turning next to FIG. 8, a flowchart of a process for starting a JVM using
classpath values is depicted in accordance with a preferred embodiment of
the present invention. The process begins by checking the profile manager
to determine whether the classpath "OS2.ibm.java.classpath" exists in the
user profile data structure for a user profile (step 800). This classpath
is the user defined classpath. Next, a determination is made as to whether
the classpath is set in the profile manager (step 802). This determination
is made by checking the user profile data structure for the selected user.
If the user classpath is set in the profile manager, the process then
initializes the JVM initialization arguments (Initargs) data structure to
use the classpath in the user profile (step 804). Then, an instance of the
virtual machine is created (step 806) with the process terminating
thereafter.
With reference again to step 802, if the classpath is not set in the
profile manager, a determination is then made as to whether the user wants
to use the system class path (step 808). If the user does not want to use
the system classpath, the process then proceeds to step 806 to create an
instance of the JVM. The instance of the JVM is created by calling a Java
native interface (JNI) application programming interface (API). A Java
native interface is a native programming interface that allows Java code
that runs inside a Java virtual machine to interoperate with applications
and libraries written in other programming languages, such as C, C++ and
assembly. In the depicted example, the JNI API provides an interface for
native applications, such as a browser, to reach Java. The JNI is used to
translate messages from other Java objects or components into calls used
by the browser and to translate responses from the browser into messages
that are recognized by Java objects or components. An example of a JNI API
is JNI_CreateJavaVM. JNI are found in the Java Development Kit (JDK)
available from Sun Microsystems, Inc. If the user does want to use the
system classpath, the JVM is initialized from InitOrgs data structure to
use the system classpath name (step 810) with the process terminating
thereafter. Depending on the implementation, the user may actually be an
application that uses the processes of the present invention to select or
change classpaths. In such an implementation, the GUI interfaces may be
bypassed with the selections being made directly by the application to the
user profile data structure.
Turning next to FIG. 9, a diagram of a JVM initialization data structure is
depicted in accordance with a preferred embodiment of the present
invention. JVM initialization data structure 900 illustrates various
parameters that are used as a JNI API to initialize a JVM.
Thus, the present invention provides an improved method, apparatus, and
instructions for allowing flexibility in selecting classpaths used to load
classes for a JVM. For example, the present invention is useful in placing
improved classes ahead of standard classes having the same name such that
these improved classes are given preference in loading for use with the
JVM. In particular, the present invention provides a GUI that allows a
user to specify classpaths for use with a JVM when the JVM is initiated by
the browser. When switching to a different JVM, the classpaths also may be
switched to optimize performance of the JVM.
It is important to note that while the present invention has been described
in the context of a fully functioning data processing system, those of
ordinary skill in the art will appreciate that the processes of the
present invention are capable of being distributed in a form of a computer
readable medium of instructions and a variety of forms and that the
present invention applies equally regardless of the particular type of
signal bearing media actually used to carry out the distribution. Examples
of computer readable media include recordable-type media such a floppy
disc, a hard disk drive, a RAM, and CD-ROMs and transmission-type media
such as digital and analog communications links.
The description of the present invention has been presented for purposes of
illustration and description, but is not limited to be exhaustive or
limited to the invention in the form disclosed. Many modifications and
variations will be apparent to those of ordinary skill in the art. For
example, the processes of the present invention may be applied to change
classpaths dynamically or at run time. The embodiment was chosen and
described in order to best explain the principles of the invention, the
practical application, and to enable others of ordinary skill in the art
to understand the invention for various embodiments with various
modifications as are suited to the particular use contemplated.
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