Abstract:
A system for animating the visualization of exceptions thrown by an application includes an application server; an application program; an in-memory exception table; an exception log file; an analysis database; and a user interface. The application server is operable for executing the application program during a server session including a plurality of analysis windows; responsive to exceptions thrown by the application program during execution for logging exception data to the in-memory exception table; responsive to completing an analysis window, logging the exception table to the exception log file; responsive to completing the server session, for building an analysis database from the exception log file; and generating from the exception log file an exception visualization animation including a sequential plurality of exception table renditions to the user interface.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field of the Invention  
         [0002]     This invention relates to program debugging. More particularly, it relates to visualizing exception generation.  
         [0003]     2. Background Art  
         [0004]     Developing and debugging software is difficult, in part because most software code executes invisibly. While there are typically user-visible manifestations of software behavior, such as user interfaces, there is a great deal of processing that goes on behind the scenes that is not visible.  
         [0005]     Tools that can help developers to visualize this “behind the scenes” processing can speed up the development process, as well as make it easier to find and fix defects and thereby improve quality.  
         [0006]     Many programming languages provide an explicit “exception” construct as a way for code to handle unexpected or atypical conditions. One part of the code will “throw” an exception, while another part of the code (perhaps in a separate code module) will “catch” and “handle” the exception. Both Java and C++, for example, support exceptions (try/catch blocks, and the throw statement).  
         [0007]     There are tools available today that make some aspects of program structure and behavior visible to developers. There are tools that perform static analysis of source code, for example, and generate class diagrams from code files. Such tools are limited in that they are not looking at the dynamic, run-time behavior of software but rather at its structure. There are tools that look explicitly at exceptions and how they propagate, but these tools are also based on static analysis of code, and not on run-time behavior.  
         [0008]     Software debuggers are another class of tool that supports visualization of software. Debuggers are focused on run-time behavior, and can help to analyze exceptions (e.g., by setting breakpoints near throw or catch statements). Debuggers do not, however, provide tools for the visualization of the history of exceptions. Instead such debuggers focus on a single instance of an exception at a time. In some cases, a limited form of exception history might be maintained but it is usually nothing more than a simple count. In other cases, static propagation of exceptions focused on code path may be traced, there is no evaluation of classes of exceptions.  
       SUMMARY OF THE INVENTION  
       [0009]     A system, method, and program storage device for animating the visualization of program exceptions by executing an application program during a server session including a plurality of analysis windows; monitoring the application program for a thrown exception; responsive to the thrown exception, logging exception data to an exception table; responsive to conclusion of each analysis window, appending the exception table to a log file; and upon ending the server session, building an analysis database for rendering exception visualization animation to a user.  
         [0010]     Other features and advantages of this invention will become apparent from the following detailed description of the presently preferred embodiment of the invention, taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a high level system diagram illustrating the components of a preferred embodiment of the invention.  
         [0012]      FIG. 2  is a flow chart illustrating the steps of the preferred embodiment of the process of the invention.  
         [0013]      FIG. 3  is a diagram illustrating the format of the in-memory exception table of  FIG. 1 .  
         [0014]      FIG. 4  is a diagram illustrating the format of the analysis database of  FIG. 1 .  
         [0015]      FIG. 5  is a diagram illustrating the format of the visualization animations of  FIG. 1 .  
         [0016]      FIG. 6  is a class diagram example of an alternative visualization animation example.  
         [0017]      FIG. 7  is a high level representation of a program storage device for controlling the operation of a computer according to the preferred embodiments of the invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0018]     In accordance with the preferred embodiment of the invention, a system and method is provided for visualizing historical exception data generated during execution of a software system that is capable of logging exception data in order to provide a “big picture” perspective of the history of exception processes. An exception log is provided that contains at least the time that an exception occurred, a unique identifier of the type of exception, and an identification of the part of the code that threw the exception. Building on this log, an exception history is visualized based on run-time data which allows for “replay” of the exception history and therefore supports post-execution analysis, and evaluates a collection of exceptions, rather than examining the processing of a single exception, thus allowing for detection of patterns of exception behavior (e.g., sets of exceptions that occur together.  
         [0019]     In an exemplary embodiment, the exception history is analyzed and then displayed in tabular form, starting with the earliest exception data. The display is then animated by moving forward in the history log, and updating the tabular display to show which exceptions have occurred during an analysis window. For example, the tabular display might move through the exception data in 10 minute increments. For each 10 minute interval, the tabular display would highlight any new exceptions generated. This display of exceptions can then be analyzed to identify areas of the code that should be examined further. For example, in the example presented hereafter, animation shows that the java.lang.ClassNotFoundException is occurring in most analysis intervals, and the total count of this exception is very high compared to the other exceptions. This behavior is either an outright error, or else a sign of unoptimized code (code that should not continually look for a class that does not exist). Each combination of exception type/exception source may be assigned in position in the table that never changes, in order to facilitate pattern detection.  
         [0020]     Referring to  FIG. 1 , application server  10  executes application code  12  and enters exceptions encountered in in-memory exception table  14 . Periodically, table  14  contents are appended to an exception log file  16 . For analysis, an analysis database  18  is built from log file  16  and a series of visualization animations  20  presented to the user.  
         [0021]     In operation, referring to  FIG. 2 , in step  110  an application server  10  session is started. In step  112 , application program  12  is executed and, in step  114 , monitored for exceptions. In steps  116 ,  118 , if an exception is thrown by an application program  12  method or class, exception data is logged to in-memory exception table  14 . This continues until, in step  120 , the end of analysis window, say 10 minutes, is reached, whereupon in step  122  the contents of exception table  14  are appended to the end of exception log file  16 . This process continues until, in step  124 , the end of a test session and application program execution and exception monitoring ends. Thereupon, in steps  126 ,  128  each table  14  in log file  16  is added to analysis database  18  for building its visualization and in step  130  visualization animations rendered to the user.  
         [0022]     Table 1 presents some Java code as an example of application source code  12  that illustrates exception throwing and catching.  
                         TABLE 1                       EXCEPTION THROWING AND CATCHING                                    // Define a new Exception class           class SampleException extends Exception {            SampleException(String s) {             super(s);            }           }           // This class throws an exception when the method              “testMethod” is called.           class TestException{            void testMethod( ) throws SampleException {             throw new SampleException(“Example”);            }           }           // This class catches the exception thrown by testMethod           class Test {            public static void main(String[ ] args){             try {              new TestException( ).testMethod( );             }catch(SampleException e) {              System.out.println(e.getMessage( ));             }            }           }                      
 
         [0023]     In the example of Table 1, it is possible to analyze exception propagation by analyzing the method calls in source code  12 . For example, the method “testMethod” declares that it throws the exception “SampleException”. Thus, it can be inferred that a SampleException would propagate from testMethod up to any caller of testMethod. This analysis of method calls and exceptions is referred to as “structural analysis” or “static analysis”. Run-time analysis, on the other hand, is performed on a running software system. Structural analysis tells what might happen; run-time analysis looks at what actually happens. Prior art, for example Java compilers, exists for performing structural analysis of exception throwing.  
         [0024]     However, this analysis of structure does not provide much information about what will happen when the program  12  executes. Although in the artificial example of Table 1 an example will be thrown on each call to testMethod, in reality exceptions are thrown at unpredictable times, usually in response to unusual conditions.  
         [0025]     Insight into the behavior of a running program  12  is provided by keeping a record of which exceptions are thrown, when they are thrown, and from where. Analysis of the historical record of exceptions can aid understanding of the relative frequency of exceptions. Further, when examining the exception record across an entire system, potential patterns of exceptions can be detected that may lead to defects, or that might suggest ways of refactoring or restructuring the code  12  to make it more reliable or better performing.  
         [0026]     In accordance with the preferred embodiment of the invention, an application server  10  keeps track of exception activity resulting from execution of code  12 , and keeps it in an in-memory table  14 . There is an entry in this table  14  for each unique combination of exception type and source line. For example, there would be two different entries in this table  14  for a java.lang.NullPointerException if it was thrown from two different parts of the program  12  under test.  
         [0027]     Referring to  FIG. 3 , each entry in the in-memory exception activity table  14  contains the following information: index  32  and activity marker  30 , count  34  of occurrences since server  10  start, time  36  when the exception was last thrown, exception class  38 , class  40  that threw the exception, and line number  42  (the probe identifier within the class of code  12  that threw the exception).  
         [0028]     In-memory table  14  is periodically appended to a file  16 . The result of this appending is a history of all the transactions that have occurred within an instance of the application server  10  occasioned by code  12  since the server  10  was started. Table 2 is an example of such a file, and contains a sequence of exception tables  14 , with the oldest tables at the beginning and the most recent table at the end. The example of Table 2 illustrates one such exception log  16 ; this excerpt contains two distinct dumps of the in-memory exception table  14 .  
                                                                   TABLE 2                           TRANSACTION HISTORY FILE EXAMPLE - LOG OF IN-MEMORY EXCEPTION TABLE DUMPS            Index   Occurrences   Time of last Occurrence   Exception   SourceId   ProbeId                    1   1   03.11.06 09:47:10:922 EST   java.io.FileNotFoundException   com.ibm.ejs.jms.listener.AsyncMessageLog.readRequestLogFile   128       +2   1   03.11.06 09:47:10:922 EST   java.lang.ClassNotFoundException   com.ibm.ws.activity.ActivityServiceInterceptor.loadMigrationImpls   424       +3   1   03.11.06 09:47:15:391 EST   com.ibm.ws.naming.jcache.CacheEntryNotFoundException   com.ibm.ws.naming.util.WanInitCtxFactory.getInitialContextInternal   367       +4   1   03.11.06 09:47:16:062 EST   javax.naming.NameAlreadyBoundException   com.ibm.ws.naming.ipcos.WsnOptimizedNamingImpl.do_bind_new_corba_context   1042       +5   1   03.11.06 09:47:16:062 EST   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext   2155       +6   1   03.11.06 09:47:16:078 EST   javax.naming.nameAlreadyBoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext   756       +7   1   03.11.06 09:47:16:500 EST   org.omg.CoaNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase.bind_new_corba_context   944       +8   1   03.11.06 09:47:16:500 EST   org.omg.CosNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext   2161       +9   1   03.11.06 09:47:16:516 EST   javax.naming.NameNotFoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext   756       +10   1   03.11.06 09:47:17:312 EST   java.lang.NullPointerException   com.ibm.ws.utils.VUTrace.initialisation   584       +11   1   03.11.06 09:47:17:484 EST   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup   1226       +12   1   03.11.06 09:47:17:500 EST   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup   1252       +13   1   03.11.06 09:47:18:000 EST   java.io.FileNotFoundException   com.ibm.ejs.jms.DurableSubscriptionManagerImpl.readDurableSubscriptionFile   236       +14   1   03.11.06 09:47:24:906 EST   java.lang.ClassNotFoundException   com.ibm.ws.classloader.CompoundClassLoader.loadClass   248       +15   1   03.11.06 09:47:29:531 EST   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.cosbase.WsnOptimizedNamingImplBase.executeBatchedOperations   1497       +16   1   03.11.06 09:47:38:672 EST   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.JMSTopicConnectionHandle.createDurableConnectionConsumer   168       +17   1   03.11.06 09:47:38:688 EST   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStart   281       +18   1   03.11.06 09:47:38:703 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.getExceptionListener   250       +19   1   03.11.06 09:47:38:703 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop   332       +20   1   03.11.06 09:47:38:719 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.close   345       +21   1   03.11.06 09:47:38:719 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop   372       +22   1   03.11.06 09:47:38:734 EST   com.ibm.ejs.jms.listener.MDBRunteimeException   com.ibm.ejs.jms.listener.MagListenerPort.add   140       1   3   03.11.06 09:47:17:469 EST   javax.naming.NameNotFoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext   756       2   1   03.11.06 09:47:18:000 EST   java.io.FileNotFoundException   com.ibm.ejs.jms.DurableSubscriptionManagerImpl.readDurableSubscriptionFile   236       3   2   03.11.06 09:48:39:016 EST   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.JMSTopicConnectionHandle.createDurableConnectionConsumer   168       4   6   03.11.06 09:47:36:406 EST   com.ibm.ws.naming.jcache.CacheEntryNotFoundException   com.ibm.ws.naming.util.WanInitCtxFactory.getInitialContextInternal   367       5   1   03.11.06 09:47:17:312 EST   java.lang.NullPointerException   com.ibm.ws.utils.VUTrace.initialisation   584       6   1   03.11.06 09:47:38:719 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop   372       7   3   03.11.06 09:47:17:469 EST   org.omg.CosNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext   2161       8   10   03.11.06 09:47:16:750 EST   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext   2155       9   1   03.11.06 09:47:38:734 EST   com.ibm.ejs.jms.listener.MDBRuntimeException   com.ibm.ejs.jms.listener.MsgListenerPort.add   140       10   1   03.11.06 09:47:38:703 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.getExceptionListener   250       11   12   03.11.06 09:47:32:984 EST   javax.naming.NameAlreadyBoundException   com.ibm.ws.naming.ipcos.WsnOptimizedNamingImpl.do_bind_new_corba_context   1042       12   1   03.11.06 09:47:10:922 EST   java.lang.ClassNotFoundException   com.ibm.ws.activity.ActivityServiceInterceptor.loadMigrationImpls   424       13   1   03.11.06 09:47:38:703 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop   332       14   4   03.11.06 09:47:17:516 EST   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup   1226       15   1   03.11.06 09:47:38:688 EST   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStart   281       16   10   03.11.06 09:47:16:750 EST   javax.naming.NameAlreadyBoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext   756       17   2   03.11.06 09:47:17:516 EST   javax.naming.nameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup   1252       18   3   03.11.06 09:47:17:469 EST   org.omg.CosNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase.bind_new_corba_context   944       19   716   03.11.06 09:47:46:562 EST   java.lang.ClassNotFoundException   com.ibm.ws.classloader.CompoundClassLoader.loadClass   248       20   2   03.11.06 09:47:32:984 EST   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase.executeBatchedOperations   1497       21   1   03.11.06 09:47:38:719 EST   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.close   345       22   1   03.11.06 09:47:10:047 EST   java.io.FileNotFoundException   com.ibm.ejs.jms.listener.AsyncMessageLog.readRequestLogFile   128       +23   1   03.11.06 09:48:39:031 EST   com.ibm.ejs.jms.listener.MDBRuntimeException   com.ibm.ejs.util.am._Alarm.run   75                  
 
         [0029]     The format of each exception table within the log file is: 
        A two-line header  44      A line of hyphens  46      A list  48  of exception records, where the data values are separated by spaces 
 
 Special cases in the list of exception records of Table 2 include the following. Exception records that are new since the last dump are printed out following a line of hyphens; and the index  32  for such records begins with a “+” sign  30 . 
       
 
         [0033]     Table 3 sets forth a pseudo-code statement for importing the exception log  16  of Table 2 into a database  18 , such as a Notes view, for display and analysis. In this example implementation, a Lotus Notes database is used to store the log entries, but any other type of database is suitable.  
                         TABLE 3                       PROCESS FOR CONVERTING EXCEPTION LOG INTO       ANALYSIS DATABASE                                    Pseudocode for main program             Open the exception log             Set table counter to 0             For each exception table in the exception log               Increment table counter               ImportExceptionRecords(table counter)             Close the exception log           Pseudocode for ImportExceptionRecords             Read lines from the exception log until the word             “index” is encountered             Skip 2 lines             Do the following until a blank line is encountered               If the line begins with hyphen, continue               If the line begins with a number (or with a +),               then,                 Extract the index field from the line                 Extract the count field from the line                 Extract the timestamp field from the line                 Extract the exception field from the line                 Extract the source class field from the line                 Extract the line number field from the line                 Copy the above values into a new entry in a                 Notes database, add the table counter to the                 entry and save the entry                      
 
         [0034]     The resulting analysis database  18  of executing the process of Table 3 upon the two table dumps in log file  16  of Table 2 is illustrated in Table 4. Referring to  FIG. 3 , records in analysis database  18  of Table 4 include table number  50 , index value  52 , count  54  of exception occurrences, exception type  38 , and source  40 .  
                                                           TABLE 4                           TRANSACTION HISTORY FILE EXAMPLE - ANALYSIS DATABASE                Ex                       Id   #   Exception   Source                    1   1   1   java.io.FileNotFoundException   com.ibm.ejs.jms.listener.AsyncMessageLog.readRequestLogFile       1   2   1   java.lang.ClassNotFoundException   com.ibm.ws.activity.ActivityServiceInterceptor.loadMigrationImpls       1   3   1   com.ibm.ws.naming.jcache.CacheEntryNotFoundException   com.ibm.ws.naming.util.WanInitCtxFactory.getInitialContextInternal       1   4   1   javax.naming.NameAlreadyBoundException   com.ibm.ws.naming.ipcos.WsnOptimizedNamingImpl.                       do_bind_new_corba_context       1   5   1   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext       1   6   1   javax.naming.nameAlreadyBoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext       1   7   1   org.omg.CoaNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase.                       bind_new_corba_context       1   8   1   org.omg.CosNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext       1   9   1   javax.naming.NameNotFoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext       1   10   1   java.lang.NullPointerException   com.ibm.ws.utils.VUTrace.initialisation       1   11   1   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.                       UrlContext.lookup       1   12   1   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.                       lookup       1   13   1   java.io.FileNotFoundException   com.ibm.ejs.jms.DurableSubscriptionManagerImpl.                       readDurableSubscriptionFile       1   14   1   java.lang.ClassNotFoundException   com.ibm.ws.classloader.CompoundClassLoader.loadClass       1   15   1   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.cosbase.WsnOptimizedNamingImplBase.                       executeBatchedOperations       1   16   1   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.JMSTopicConnectionHandle.                       createDurableConnectionConsumer       1   17   1   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStart       1   18   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.getExceptionListener       1   19   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop       1   20   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.close       1   21   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop       1   22   1   com.ibm.ejs.jms.listener.MDBRunteimeException   com.ibm.ejs.jms.listener.MagListenerPort.add       2   1   3   javax.naming.NameNotFoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext       2   2   1   java.io.FileNotFoundException   com.ibm.ejs.jms.DurableSubscriptionManagerImpl.                       readDurableSubscriptionFile       2   3   2   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.JMSTopicConnectionHandle.                       createDurableConnectionConsumer       2   4   6   com.ibm.ws.naming.jcache.CacheEntryNotFoundException   com.ibm.ws.naming.util.WanInitCtxFactory.getInitialContextInternal       2   5   1   java.lang.NullPointerException   com.ibm.ws.utils.VUTrace.initialisation       2   6   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop       2   7   3   org.omg.CosNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext       2   8   10   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext       2   9   1   com.ibm.ejs.jms.listener.MDBRuntimeException   com.ibm.ejs.jms.listener.MsgListenerPort.add       2   10   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.getExceptionListener       2   11   12   javax.naming.NameAlreadyBoundException   com.ibm.ws.naming.ipcos.WsnOptimizedNamingImpl.                       do_bind_new_corba_context       2   12   1   java.lang.ClassNotFoundException   com.ibm.ws.activity.ActivityServiceInterceptor.loadMigrationImpls       2   13   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop       2   14   4   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup       2   15   1   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStart       2   16   10   javax.naming.NameAlreadyBoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext       2   17   2   javax.naming.nameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup       2   18   3   org.omg.CosNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase.                       bind_new_corba_context       2   19   716   java.lang.ClassNotFoundException   com.ibm.ws.classloader.CompoundClassLoader.loadClass       2   20   2   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase.                       executeBatchedOperations       2   21   1   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.close       2   22   1   java.io.FileNotFoundException   com.ibm.ejs.jms.listener.AsyncMessageLog.readRequestLogFile       2   23   1   com.ibm.ejs.jms.listener.MDBRuntimeException   com.ibm.ejs.util.am._Alarm.run                  
 
         [0035]     Once the raw exception data has been stored in a Notes database  18  (as in Table 4), it is then possible to create animations of the data to show how exceptions vary over time. For example, one possible animation  20  displays each exception table dump in sequence, with highlights to show which exceptions are new. So, using the example of Table 4, there are two different exception tables, each having the format of  FIG. 5 , including count of occurrences  56 , modification flag  58 , exception  38  and source  40 . The animation will therefore display two frames of information, as in Tables 5 and 6, with each frame corresponding to an instance of an exception table  14 . In the embodiment of Tables 5 and 6, an arrow →  58  appears to the left of any exception that had activity (that is, it is either a new exception or its count increased).  
         [0036]     Table 5 illustrates the first frame of animation  20 , and Table 6 the second frame of animation  20 .  
                                 TABLE 5                           EXCEPTION LOG ANIMATION FRAME 1            #       Exception   Source               1   →   java.io.FileNotFoundException   com.ibm.ejs.jms.listener.AsyncMessageLog.readRequestLogFile       1   →   java.lang.ClassNotFoundException   com.ibm.ws.activity.ActivityServiceInterceptor.loadMigrationImpls       1   →   com.ibm.ws.naming.jcache.CacheEntryNotFoundException   com.ibm.ws.naming.util.WanInitCtxFactory.getInitialContextInternal       1   →   javax.naming.NameAlreadyBoundException   com.ibm.ws.naming.ipcos.WsnOptimizedNamingImpl.                   do_bind_new_corba_context       1   →   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext       1   →   javax.naming.nameAlreadyBoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext       1   →   org.omg.CoaNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase.                   bind_new_corba_context       1   →   org.omg.CosNaming.NamingContextPackage.NotFound   com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext       1   →   javax.naming.NameNotFoundException   com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext       1   →   java.lang.NullPointerException   com.ibm.ws.utils.VUTrace.initialisation       1   →   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup       1   →   javax.naming.NameNotFoundException   com.ibm.ws.naming.urlbase.UrlContext.lookup       1   →   java.io.FileNotFoundException   com.ibm.ejs.jms.DurableSubscriptionManagerImpl.                   readDurableSubscriptionFile       1   →   java.lang.ClassNotFoundException   com.ibm.ws.classloader.CompoundClassLoader.loadClass       1   →   org.omg.CosNaming.NamingContextPackage.AlreadyBound   com.ibm.ws.naming.cosbase.WsnOptimizedNamingImplBase.                   executeBatchedOperations       1   →   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.JMSTopicConnectionHandle.                   createDurableConnectionConsumer       1   →   com.ibm.mq.jms.BrokerCommandFailedException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStart       1   →   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.getExceptionListener       1   →   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop       1   →   javax.jms.IllegalStateException   com.ibm.ejs.jms.JMSConnectionHandle.close       1   →   javax.jms.IllegalStateException   com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop       1   →   com.ibm.ejs.jms.listener.MDBRunteimeException   com.ibm.ejs.jms.listener.MagListenerPort.add                  
 
         [0037]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                   
               
               
                 EXCEPTION LOG ANIMATION FRAME 2 
               
             
          
           
               
                 # 
                   
                 Exception 
                 Source 
               
               
                   
               
             
          
           
               
                 1 
                   
                 java.io.FileNotFoundException 
                 com.ibm.ejs.jms.listener.AsyncMessageLog.readRequestLogFile 
               
               
                 1 
                   
                 java.lang.ClassNotFoundException 
                 com.ibm.ws.activity.ActivityServiceInterceptor.loadMigrationImpls 
               
               
                 6 
                 → 
                 com.ibm.ws.naming.jcache.CacheEntryNotFoundException 
                 com.ibm.ws.naming.util.WanInitCtxFactory.getInitialContextInternal 
               
               
                 12 
                 → 
                 javax.naming.NameAlreadyBoundException 
                 com.ibm.ws.naming.ipcos.WsnOptimizedNamingImpl. 
               
               
                   
                   
                   
                 do_bind_new_corba_context 
               
               
                 10 
                 → 
                 org.omg.CosNaming.NamingContextPackage.AlreadyBound 
                 com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext 
               
               
                 10 
                 → 
                 javax.naming.nameAlreadyBoundException 
                 com.ibm.ws.naming.jndicos.CNContextImpi.createSubcontext 
               
               
                 3 
                 → 
                 org.omg.CoaNaming.NamingContextPackage.NotFound 
                 com.ibm.ws.naming.cosbase.WanOptimizedNamingImplBase. 
               
               
                   
                   
                   
                 bind_new_corba_context 
               
               
                 3 
                 → 
                 org.omg.CosNaming.NamingContextPackage.NotFound 
                 com.ibm.ws.naming.jndicos.CNContextImpl.doCreateSubcontext 
               
               
                 3 
                 → 
                 javax.naming.NameNotFoundException 
                 com.ibm.ws.naming.jndicos.CNContextImpl.createSubcontext 
               
               
                 1 
                   
                 java.lang.NullPointerException 
                 com.ibm.ws.utils.VUTrace.initialisation 
               
               
                 4 
                 → 
                 javax.naming.NameNotFoundException 
                 com.ibm.ws.naming.urlbase.UrlContext.lookup 
               
               
                 2 
                 → 
                 javax.naming.NameNotFoundException 
                 com.ibm.ws.naming.urlbase.urlContext.lookup 
               
               
                 1 
                   
                 java.io.FileNotFoundException 
                 com.ibm.ejs.jms.DurableSubscriptionManagerImpl. 
               
               
                   
                   
                   
                 readDurableSubscriptionFile 
               
               
                 716 
                 → 
                 java.lang.ClassNotFoundException 
                 com.ibm.ws.classloader.CompoundClassLoader.loadClass 
               
               
                 2 
                 → 
                 org.omg.CosNaming.NamingContextPackage.AlreadyBound 
                 com.ibm.ws.naming.cosbase.WsnOptimizedNamingImplBase. 
               
               
                   
                   
                   
                 executeBatchedOperations 
               
               
                 2 
                 → 
                 com.ibm.mq.jms.BrokerCommandFailedException 
                 com.ibm.ejs.jms.JMSTopicConnectionHandle. 
               
               
                   
                   
                   
                 createDurableConnectionConsumer 
               
               
                 1 
                   
                 com.ibm.mq.jms.BrokerCommendFailedException 
                 com.ibm.ejs.jms.listener.MDBListenerImpl.internalStart 
               
               
                 1 
                   
                 javax.jms.IllegalStateException 
                 com.ibm.ejs.jms.JMSConnectionHandle.getExceptionListener 
               
               
                 1 
                   
                 javax.jms.IllegalStateException 
                 com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop 
               
               
                 1 
                   
                 javax.jms.IllegalStateException 
                 com.ibm.ejs.jms.JMSConnectionHandle.close 
               
               
                 1 
                   
                 javax.jms.IllegalStateException 
                 com.ibm.ejs.jms.listener.MDBListenerImpl.internalStop 
               
               
                 1 
                   
                 com.ibm.ejs.jms.listener.MDBRuntimeException 
                 com.ibm.ejs.jms.listener.MagListenerPort.add 
               
               
                 1 
                 → 
                 com.ibm.ejs.jms.listener.MDBRuntimeException 
                 com.ibm.ejs.util.am._Alarm.run 
               
               
                   
               
             
          
         
       
     
         [0038]     Since Table 5 represents the first set of exceptions, all of the exceptions are new and all of them are marked with an arrow → (modification flag  58 ).  
         [0039]     In the log animation frame of Table 6, arrows →  58  are placed next to a number of exceptions whose counts have increased between dumps. At the bottom of Table 6 there is one new exception (the MDBRuntimeException having been thrown from a new module com.ibm.ejs.util.am._Alarm.run).  
         [0040]     To make detection of patterns easier, the displays of Table 5 and 6 are organized so that new exceptions are added at the bottom, and the relative position of older exceptions does not change from frame to frame  20 . This display pattern is provided by the process of Table 7.  
                         TABLE 7                       PROCESS FOR DISPLAYING ANIMATED EXCEPTION LOG                                    For each exception dump in the database             Read all exceptions for this dump             If this is the first dump, then               Mark all exceptions as modified             Else               for each exception in the dump                 Compare to previous instance of exception                 If this is a new exception, then mark it as                 “modified”                 If the exception count has changed, then mark                 it as “modified”             End if             Display exception list, adding arrow next to any             “modified” entry           Continue to next dump                      
 
         [0041]     The example of Tables 5 and 6 shows a simple animation of a sequence of tables  14 , with changed entries being marked with an arrow  58 . Other various are clearly possible, including the use of color to show the rows where there is current activity, or mapping a range of colors to exception counts (so that high counts show red while low counts show green, for example). Instead of a table, a bar chart can be used.  
         [0042]     Referring to  FIG. 6 , it is also possible to map exception information into a graphical representation of program structure, since each exception includes information about the class from which the exception originated. The Unified Modeling Language (UML) is a way of diagramming program structure.  
         [0043]      FIG. 6  illustrates an example UML class diagram that shows a set of classes  60 ,  62 ,  64 ,  66 ,  68 ,  70 ,  72 , and  74  and the relationships  81 ,  83 ,  85 ,  91  between them. A typical class box  62  includes class name  93 , attributes  95 , and operations or processes  97 . Payment class  64  is an example of an abstract class. Associations between classes are illustrated by lines  81 ,  83 ,  91 , generalizations by line  85 , multiplicity by items  87 , navigatability by elements  89 .  
         [0044]     An exception history can be “played back” onto such a class diagram in much the same way it is played back in a sequence of tables  20 . The animation of such a diagram may be accomplished using the same pseudo code as in Table 7, but by altering the display logic to change the color, for example, of a class  60 , . . . , 74  from which an exception was generated. Other visualizations are possible, such as displaying counts of exceptions next to the class box  60 , displaying a histogram of exceptions next to a class box for those classes that are throwing more than one exception, or mapping the color of the class box into a range of exception counts (so that the shadings of the classes change as the exception counts rise).  
       ADVANTAGES OVER THE PRIOR ART  
       [0045]     It is an advantage of the preferred embodiments of the invention that there is provided a system and method for visualizing animations of classes of exceptions thrown during execution of application code.  
       ALTERNATIVE EMBODIMENTS  
       [0046]     It will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. Referring to  FIG. 7 , in particular, it is within the scope of the invention to provide a computer program product or program element, or a program storage or memory device such as a solid or fluid transmission medium  102 , magnetic or optical wire, tape or disc  100 , or the like, for storing signals readable by a machine, for controlling the operation of a computer  104  according to the method of the invention and/or to structure its components in accordance with the system of the invention.  
         [0047]     Further, each step of the method may be executed on any general computer, such as IBM Systems designated as zSeries, iSeries, xSeries, and pSeries, or the like and pursuant to one or more, or a part of one or more, program elements, modules or objects generated from any programming language, such as C++, Java, Pl/1, Fortran or the like. And still further, each said step, or a file or object or the like implementing each said step, may be executed by special purpose hardware or a circuit module designed for that purpose.  
         [0048]     Accordingly, the scope of protection of this invention is limited only by the following claims and their equivalents.