Java Exception Handling

Exception handling

1.try...catch Catching exceptions

The curly brackets of the try and catch blocks cannot be omitted

Catch a small exception when catching an exception, and then catch a large exception

Java7 start a catch block to catch multiple exceptions, multiple exceptions "|" Separate

　　　　

Access exception information

　　

2. Use finally to reclaim resources

Garbage collection in Java only reclaims resources consumed by objects in heap memory, and physical resources need to be explicitly recycled

Finally blocks are always executed (unless the SYSTEM.EXIT (1) statement is called to exit the virtual machine)

Finally, try not to use return or throw and other statements that lead to the termination of the method (because the return statement in the Try,,,catch,,,,, is not executed immediately after the call, but first to execute the FINALLY statement, executed and then back to try to execute, if, After a return is called in the Finall, the try is no longer executed)

3. Exception Handling Nesting

4. A try statement (JAVA7) that automatically closes a resource

Try the parentheses to achieve resource closure, to ensure that resources are closed, this resource must implement the Autocloseable or Closeable interface, the implementation of both interfaces, must be close ()

5.Checked anomaly and runtime anomaly system

Checked exceptions must be handled explicitly, with catch or throws

6. Throwing Exceptions using throws

7. Throw with throw: throws an exception by itself, only throws an instance

　　　　

8. Custom exception class: Inherit exception or RuntimeException

9. Throw the exception again with throw in catch

10. Abnormal chain

Exception tracking stack for 11.Java

12. Exception Handling Rules

Java Exception Handling