How to better handle exceptions

background

        In actual development, we all hope that the program can always follow the expected process and go without any errors. However, due to unavoidable internal and external factors, abnormal situations may occur, ranging from error reporting to data confusion and service unavailability. It seriously affects the stability of the system and even the user experience, causing adverse effects.

        Therefore, in actual development, we should not only consider the normal process, but also consider some possible abnormal situations and the processing strategies for this exception. Exception handling logic is a critical part of ensuring that software handles errors and exceptions gracefully at runtime.

        Therefore, during development, we must not only consider how to meet functional needs, but also how to deal with possible abnormal situations.

Why exception handling is important 

        Exception handling plays an extremely important role in development. Here are some reasons why exception handling is crucial:

1. Program stability: Software may encounter various unexpected situations when running. Appropriate exception handling can prevent these situations from causing program crashes or unpredictable behavior, thus improving the stability and reliability of the software. A stable system can greatly reduce the time you spend dealing with subsequent exceptions , and instead focus on the functions you are doing.
2. User experience: Users may enter invalid data or perform incorrect operations. If poor exception handling causes the program to crash or the error message is unclear, the user experience will be affected. With good exception handling, you can provide users with friendlier feedback , helping them understand the problem and take appropriate action.
3. Troubleshooting and debugging: When an exception or error occurs in the software, good exception handling can provide useful error information and stack traces to help developers quickly locate the problem. This helps reduce troubleshooting time and improve development efficiency.
4. Data integrity: When dealing with database operations, file reading and writing, etc., if there is no appropriate exception handling, data may be damaged or lost. By catching and handling exceptions, data integrity and consistency can be ensured .
5. Code Robustness and Maintainability: Exception handling is part of code robustness and maintainability. Proper exception handling can reduce the probability of code problems and make the code easier to maintain because the error handling logic is encapsulated in one place.
6. Compliance requirements: Certain industries or fields may have specific compliance requirements for software exception handling, such as medical, financial and other fields. Compliance requirements may require detailed logging and reporting of exceptions.

        In short, exception handling is not only a technical practice, but also an important means to ensure the stable operation of software, user satisfaction, and data security under various circumstances. A good exception handling strategy can help improve the quality and reliability of software and reduce the impact of potential problems on the business.

What are the unusual scenarios?

        In daily development, there are many common scenarios that may cause exceptions. Common, possible exception scenarios that we need to consider when designing and implementing programs:

1. Request input:  The legality, format, length and range of the request input data need to be verified to avoid incorrect data causing exceptions. By verifying the data, use guard statements to quickly fail unsatisfactory situations to avoid triggering deeper exceptions;

2. Network request: Network requests may cause exceptions due to connection timeout, server errors, network instability, etc.

3. File operations: File reading, writing, creation, deletion and other operations may cause exceptions due to file non-existence, permission issues, etc.

4. Database operations: Database query, insert, update, delete and other operations may cause exceptions due to non-existence of data, incorrect data format, database connection problems, etc.

5. Concurrent access: When multiple threads or processes access shared resources at the same time, concurrency-related exceptions may occur, such as race conditions, deadlocks, etc.

6. Third-party calls: When calling external APIs, services, and libraries, exceptions may occur due to server unavailability, response errors, etc.

7. Time and date processing: Incorrect date formats, time zone issues, leap seconds, etc. may cause time and date processing exceptions.

8. Numerical calculations: Division by zero, overflow, infinity, etc. in numerical calculations may cause mathematical calculation exceptions.

9. Memory management: When dynamic memory is allocated and released, memory management abnormalities such as insufficient memory and memory leaks may occur.

10. Configuration and environment: Incorrect configuration parameters, environment variables, file paths, etc. may cause configuration and environment-related exceptions.

11. Security issues: Lack of input validation can lead to security vulnerabilities such as cross-site scripting attacks (XSS), SQL injection, etc.

12. Natural factors: Sudden factors such as power outages, network outages, hardware failures, etc. may cause abnormalities.

13. Version compatibility: Different versions of libraries, dependencies, or systems may cause compatibility issues.

        When facing these scenarios that may cause exceptions, appropriate exception handling should be carried out according to the situation to ensure that the program can handle the problem gracefully, avoid crashes or error situations, and improve the stability and reliability of the software.

What are the good practices for exception handling?

        During the development process, there are some excellent exception handling practices that can help you effectively deal with possible exceptions. Here are some practices worth considering:

1. Indicate the source of the exception : This is very important. When we call other people's methods or third-party interfaces, if an exception occurs in the interface provided by the other party, but the exception is indeed displayed in our method, the responsibility lies with us; therefore, we can When calling other people's interfaces, based on distrust, when catching exceptions, the exceptions are encapsulated and the source is identified before forwarding or processing; on the one hand, it is convenient to locate the source of the exception; on the other hand, it is also convenient to attribute the responsibility for the exception;

2. Clear exception types: A clearly defined exception type hierarchy makes the types and meanings of exceptions more readable. This helps developers better understand where exceptions come from and how to handle them.

3. Control exception granularity: Classify exceptions into levels with appropriate granularity so that you can take more targeted measures when catching and handling exceptions. Don't cover the entire code block without thinking.

4. Reasonable exception handling strategy: After catching an exception, consider whether to recover, retry, ignore or report the exception based on the type and context of the exception. Avoid simply printing error messages.

5. Consider the exception alarm mechanism : In most cases, we are often busy with development work, and it is impossible to manually monitor the occurrence of exceptions all the time. At the same time, we should try to minimize the number of users reporting abnormal situations, because when users feedback, the exception may have already been caused. had some adverse effects. Therefore, when handling exceptions, establish an alarm mechanism to remind relevant personnel through emails or messages to learn about abnormal situations in time to adopt response strategies . On the one hand, when an exception occurs, it can be notified in time to maintain timeliness. At the same time, the user is notified and the processing power is handed over to the user to avoid bigger problems caused by the user's ignorance; on the other hand, through the abnormal alarm related This facilitates the division of responsibilities and avoids the responsibility being placed on one's own side due to untimely notification.

6. Record error information: When an exception is caught, detailed information about the exception is recorded, including stack trace, timestamp, exception type and context information, etc. If necessary, exception information can be persisted, which helps with subsequent troubleshooting and debugging .

7. Provide friendly user feedback: For user-visible exceptions, such as user input errors, provide clear and friendly error prompts to help users understand the problem.

8. Handle exceptions layer by layer: In a multi-layer architecture, exceptions should be caught and handled at the appropriate layer. The lower layer should focus more on resource management and finer-grained exceptions, while the higher layer should handle higher-level business logic exceptions.

9. Correct release of resources: Use try-finallyor try-with-resources(in languages ​​that support this feature) to ensure that resources are released correctly when an exception occurs to avoid resource leaks.

10. Custom Exceptions: Create custom exception classes for specific error conditions to provide a more informative exception type that can carry additional contextual information.

11. Logging: When an exception is captured, the exception information is recorded in the log for subsequent analysis and troubleshooting. Logs can provide developers with detailed information about what happened when an exception occurred.

12. Exception handling process testing: During the development phase, unit tests and integration tests are written for different exception situations to ensure that the exception handling logic works correctly.

13. Graceful degradation : Implement graceful degradation strategies in operations that may fail to ensure that some functionality remains available even under abnormal circumstances.

14. Fallbacks: For critical operations, consider fallbacks or fault-tolerance strategies to continue providing basic functionality during abnormal situations.

15. Regularly review exception handling: Regularly check and review exception handling code to ensure its applicability, correctness and consistency.

        By adopting these excellent exception handling practices, you can effectively deal with various possible abnormal situations and improve the stability, reliability and user experience of your program.