Method and system for checking the consistency of application jar files

• US 8,914,784 B2
• Filed: 06/10/2011
• Issued: 12/16/2014
• Est. Priority Date: 06/10/2011
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Arcese, Mauro, Pichetti, Luigi, Sidoti, Stefano
• Primary Examiner(s): Zhen, Li B
• Assistant Examiner(s): NGUYEN, DUY KHUONG THANH
• Application Number:
  US13/157,467
• Publication Number:
  US 20120317563A1
• Time in Patent Office: 1,285 Days
• Field of Search: 717/170
• US Class Current: 717/170
• CPC Class Codes: G06F 11/0718 in an object-oriented system
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 9/44552 Conflict resolution, i.e. enabling coexistence of conflicting executables
• CPC Class Codes: G06F 9/45529 Embedded in an application, e.g. JavaScript in a Web browser

Abstract

A computer method and system dynamically provide consistency of Java application files. A processor executed routine is configured (e.g., instrumented as an agent) to intercept each class that is loaded into a subject Java application or JVM. The system computes a cyclic redundancy check (CRC) of the respective JAR file surrounding the loaded class. The system compares the computed CRC value to a CRC value of at least one other copy of the respective JAR file. Based on results of the comparison, the system determines consistency (e.g., same version) of the multiple copies of the respective JAR file used by the subject Java application. If the multiple copies of the respective JAR file are determined to be inconsistent, the system alerts the user and/or enables the application to abort. The comparative CRC value may be stored in a repository; and the step of comparing looks up the stored CRC value in the repository.

Claims

1. A computer system providing consistency of Java application files, comprising:

a computer routine, executed by a processor, automatically intercepting each class that is loaded into a subject Java application, for each class, the class having a respective Java Archive (JAR) file, and the computer routine retrieving the respective JAR file; and

a Java version detector operatively coupled to the processor;

(i) computing cyclic redundancy check (CRC) of the retrieved respective JAR file, resulting in a computed CRC value of the respective JAR file;

(ii) if the respective JAR file has been previously encountered by the subject Java application, automatically comparing the computed CRC value to a CRC value of at least one other copy of the respective JAR file, wherein the at least one other copy of the respective JAR file is used by the subject Java application; and

(iii) based on results of the comparing, determining consistency of multiple copies of the respective JAR file used by the subject Java application, and alerting a user when the multiple copies of the respective JAR files are determined to be inconsistent, in a manner dynamically ensuring consistency of the subject Java application files.

2. The system as claimed in claim 1, wherein the subject Java application is composed by multiple running Java virtual machines, different Java virtual machines referencing different copies of the same JAR files.

3. The system as claimed in claim 1, wherein the CRC value of the one other copy of the respective JAR file is stored in a repository;

and

the Java version detector looks up the stored CRC value in the repository and compares the computed CRC value to the stored CRC value as looked-up in the repository.

4. The system as claimed in claim 1, wherein the Java version detector determines when the multiple copies of the respective JAR file are inconsistent and aborts the subject Java application.

5. The system as claimed in claim 1, wherein the Java version detector determines when the multiple copies of the respective JAR file are inconsistent and notifies the subject Java application.

6. The system as claimed in claim 1, wherein the Java version detector comparing the computed CRC value is with respect to a pre-specified CRC value, the CRC value of the at least one other copy of the respective JAR file being the pre-specified CRC value.

7. The system as claimed in claim 1, wherein the Java version detector comparing the computed CRC value is relative to CRC values of the multiple copies of the respective JAR file.

8. The system as claimed in claim 1, wherein the Java version detector determining consistency further provides immediate detection of updates having been uniformly performed on the multiple copies of the respective JAR file.

9. The system as claimed in claim 1, wherein the Java version detector determining consistency includes detecting corruption of at least one of the multiple copies of the respective JAR file.

10. The system as claimed in claim 1, wherein the computer routine employs an agent registered to intercept each class, the agent being defined through the JRE instrumentation interface.

11. A computer program product ensuring consistency of Java application files, the computer program product comprising:

a computer readable non-transitory storage medium having computer readable program code embodied therewith,

the computer readable program code comprising computer readable program code configured to;

automatically intercept a class that is loaded into a subject Java application, the class having a respective Java Archive (JAR) file;

retrieve the respective JAR file;

compute cyclic redundancy check (CRC) of the retrieved respective JAR file resulting in a computed CRC value of the respective JAR file;

if the respective JAR file has been previously encountered by the subject Java application, automatically compare the computed CRC value to a CRC value of at least one other copy of the respective JAR file, wherein the at least one other copy of the respective JAR file is used by the subject Java application; and

based on results of the comparing, determining consistency of multiple copies of the respective JAR file used by the subject Java application and alerting a user when the multiple copies of the respective JAR files are determined to be inconsistent, such that consistency of the subject Java application files is dynamically ensured.