United States Patent m cm Patent Number: 5,630,066
Gosling  Date of Patent: May 13, 1997
 SYSTEM AND METHOD FOR LOCATING OBJECT VffiW AND PLATFORM INDEPENDENT OBJECT
 Inventor: James A. Gosling, Woodside, Calif.
 Assignee: Sun Microsystems, Inc., Mountain
 Appl. No.: 359,884
 Filed: Dec 20,1994
 Int CI.6 G06F 9/24; G06F 13/38;
 U.S. CI 395/200.09; 395/183.22;
395/800; 364/DIG. 1; 364/DIG. 2
 Field of Search 395/700, 456,
395/600, 728, 650, 200.09, 800, 159, 155, 446, 200.15, 200.16, 183.22; 364/DIG. 1,
 References Cited
U.S. PATENT DOCUMENTS
5,075,847 12/1991 Fromme 395/700
5,386,568 1/1995 Wold et al 395/700
5,434,992 7/1995 Mattson.
5,437,027 7/1995 Bannonetal 395/600
Primary Examiner—Daniel H. Pan
Attorney, Agent, or Firm—Gary S. Williams; Flehr Hohbach Test Albritton & Herbert LLP
A class loader downloads objects and object viewers from remote computer nodes, and invokes locally stored object viewers to view objects. When a user selects an object to view, a conventional downloading of the referenced object is initiated. The class loader, however, utilizes data type information received at the beginning of the object downloading process to determine if a viewer for the referenced object is available on the user's workstation. If an appropriate view is not locally available, the class loader automatically locates an appropriate viewer on the server from which the object is being downloaded, or from any other appropriate server known to the user's workstation. The class loader downloads the located viewer and then invokes a program verification procedure to verify the integrity of the downloaded viewer before the viewer is executed. Once a viewer has been verified, the viewer is added to the user's local viewer library, downloading of the referenced object is completed, and execution of the viewer to view the downloaded object is enabled. If an appropriate viewer cannot be located, or the only viewer located" does not pass the verification procedure, downloading of the referenced object is aborted.
12 Claims, 13 Drawing Sheets