There are several other ways you can find and diagnose less common Java exceptions in your application in addition to using an APM tool like FusionReactor:
Logging: Enabling your application can help you capture and diagnose exceptions as they occur. Using a logging framework such as Log4j or SLF4J, you can configure your application to log exceptions at different levels (e.g., error, warning, info) and to output the stack trace of the exception to a log file.
Debugging: You can use a debugger such as Eclipse or IntelliJ to step through the execution of your application and inspect the state of the application when an exception occurs. This can help you identify the specific code line that caused the exception and understand how the exception propagated through the application.
Code review: Reviewing the application’s code can also help you identify and fix the root cause of an exception. This can be done by looking at the code that throws the exception, the methods that are called before the exception is thrown, and the variables used in the methods.
Monitoring: Monitoring the application’s resource usage, such as CPU, memory, and disk I/O, can help you identify an exception’s root cause.
Profiling: Profiling the application using a tool such as JProfiler or YourKit can help you identify performance bottlenecks and understand how the application uses its resources. This can help you identify the specific code line that caused the exception and understand how the exception propagated through the application.
It’s important to note that no single method can detect all types of exceptions, so it’s best to have a combination of techniques in place to have the most comprehensive coverage.