Creating a real-time class package to class archive file mapping index
View Patent ↗According to the preferred embodiments, an apparatus and method is described for creating a real-time class package to class archive file mapping index that improves the performance of a class loader to load needed classes in an object oriented programming environment. In preferred embodiments, the class loader includes a mapping mechanism that creates and maintains a real-time class package to file archive mapping index. In preferred embodiments, the mapping mechanism optimizes access to the file archive mapping index. In a preferred embodiment, when the mapping mechanism finds a entry in the file archive mapping index for the package, but the class is not found, the class is searched in the class path beginning from the last file archive listed in the index to optimize the search. In other embodiments, the class loader includes a large package list that is used to further optimize access to the archive index.
1. A method for creating a real-time class package to class archive file index, the method comprising the steps of:
(A) receiving a request for a class from an application;
(B) creating, using a computer processor, a record in an index in response to the request that correlates a class package with one or more class archive files;
(C) creating a large package list that contains a plurality of known large packages;
(D) searching the large package list for the class; and
(E) where the class is in a large package and the class is not contained directly in the large package, returning the package at least one level deeper than the package found to contain the class to use to look up the class in the index.
2. The method of claim 1 wherein the application program is a Java application and the class archive file is a JAR.
3. The method of claim 1 further comprising the steps of:
(F) looking up the class package in the index to find a list of one or more class archive files;
(G) searching the list for the class; and
(H) where the class is not found, searching the class path beginning after the last class archive file on the list.
4. The method of claim 1 wherein the large package list contains predetermined data.
5. The method of claim 4 wherein the predetermined data is generated by the mapping mechanism and stored for use in a subsequent invocation of the class loader.