Reliability - Java Coding Guidelines - page 162

This code need not catch ArrayIndexOutOfBoundsException because it is a runtime
exception, and such exceptions indicate programmer errors, which are best resolved by
fixing the defect.

Applicability
Use of exceptions for any purpose other than detecting and handling exceptional condi-
tions complicates program analysis and debugging, degrades performance, and can in-
crease maintenance costs.

Bibliography

[Bloch 2001]
Item 39, “Use Exceptions Only for Exceptional Conditions”

[JLS 2013]
Chapter 11, “Exceptions”

[Long 2012]
ERR08-J. Do not catch NullPointerException or any of its ancestors

43. Use a try -with-resources statement to safely handle closeable

resources

The Java Development Kit 1.7 (JDK 1.7) introduced the try -with-resources statement
(see the JLS, §14.20.3, “ try -with-resources” [JLS 2013]), which simplifies correct use of
resources that implement the java.lang.AutoCloseable interface, including those that
implement the java.io.Closeable interface.
Using the try -with-resources statement prevents problems that can arise when closing
resources with an ordinary try - catch - finally block, such as failing to close a resource
because an exception is thrown as a result of closing another resource, or masking an im-
portant exception when a resource is closed.
Use of the try -with-resources statement is also illustrated in The CERT ® Oracle ® Se-
cure Coding Standard for Java ™ [Long 2012], “ ERR05-J. Do not let checked exceptions
escape from a finally block , ” “FIO03-J. Remove temporary files before termination,”
and “FIO04-J. Close resources when they are no longer needed.”

Noncompliant Code Example

This noncompliant code example uses an ordinary try-catch-finally block in an at-
tempt to close two resources.