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This article mainly talks about "what is the method of Java exception handling". Interested friends may wish to have a look at it. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "what is the method of Java exception handling"?

1) use checked exceptions for recoverable errors and non-checked errors for programming errors.

It is always confusing for Java programmers to choose between checked or non-checked exceptions. Checked exceptions ensure that you provide exception handling code for error conditions, which is a way from language to forcing you to write robust code, but at the same time introduces a lot of cluttered code and makes it unreadable. Of course, if you have alternatives and recovery strategies, it seems reasonable to catch exceptions and do something. Choose whether to check or run-time exceptions in Java programming.

2) close or release resources in the finally block

This is a well-known good practice in Java programming and is the equivalent of a standard when dealing with networks and IO classes. Close the resources in the finally block and ensure the reasonable release of previous and scarce resources under normal and abnormal execution, which is guaranteed by the finally block. Starting with Java7, the language has a more interesting feature: resource management automation or ARM blocks can do this. However, it is important to remember to close resources in the finally block, which is important for releasing limited resources such as FileDescriptors in the case of socket and file programming.

3) include the cause of the exception in the stack trace

In many cases, when an exception caused by another exception is thrown, the Java library and open source code will wrap one exception as another. Logging and printing root exceptions become very important. The Java exception class provides a getCause () method to retrieve the cause of the exception, which can provide more information about the root cause of the exception. This Java practice is very helpful for debugging or troubleshooting. Always remember that if you wrap one exception into another, construct a new exception to pass the source exception.

4) always provide meaningful and complete information about exceptions

Exception information is the most important place, because this is the first place programmers see, where you can find the root cause of the problem. Accurate and true information is always provided here.

5) avoid excessive use of checked exceptions

The checked exception has some advantages in enforcement, but it also destroys the code and reduces the readability of the code by masking business logic. As long as you don't overuse checked exceptions, you can greatly reduce such situations, and as a result, you'll get cleaner code. You can also use the new features of Java7 to remove duplicates.

6) convert checked exceptions to run-time exceptions

This is one of the techniques used to restrict the use of checked exceptions in most frameworks such as Spring. Most of the checked exceptions from JDBC are wrapped in DataAccessException, while the (DataAccessException) exception is a non-checked exception. This is the benefit of Java good practice, where specific exceptions are limited to specific modules, such as SQLException on the DAO layer, and explicit runtime exceptions on the client layer.

7) keep in mind that exceptions are expensive for performance

One thing to keep in mind is that it is extraordinarily expensive and makes your code slow. If you have a way to read from the ResultSet, a SQLException exception is often thrown without moving to the next element, which will be much slower than normal code that does not throw an exception. So it greatly reduces unnecessary exception capture and movement, where there is no fixed reason. Don't just throw and catch exceptions, if you can use the boolean variable to represent the execution result, you may get a cleaner, higher-performance solution. Fix the root cause of the error to avoid unnecessary exception catch.

8) avoid empty catch blocks

There is nothing worse than an empty catch block, because it not only hides errors and exceptions, but also can cause your object to be unusable or dirty. Empty catch blocks can only become meaningless if you are quite sure that the exception will not continue to affect the object state in any way, but it is still better to log errors during program execution. For writing exception handling code in Java programming, this is not just an excellent Java practice, but one of the most common practices.

9) use standard exceptions

Our ninth good practice recommends the use of standard and built-in Java exceptions. Using standard exceptions instead of creating our own exceptions each time is a good choice for maintainability and consistency, both now and in the future. Reusing standard exceptions makes the code more readable, because most Java developers have standards like RuntimeException exceptions, IllegalStateException exceptions, Illegal Argument Exception exceptions or NullPointerException exceptions derived from JDK, and they can know at a glance the purpose of each exception, rather than the purpose of looking for user-defined exceptions in code or documentation.

10) record the exception thrown by any method

Java provides the throw and throws keywords to throw exceptions, and use @ throw in javadoc to record any exceptions that may be thrown by any method. This becomes very important if you write API or public interfaces. Exceptions thrown by any method are documented so that you can subconsciously remind anyone who uses it.

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