User guide

java.security.Security.setProperty("networkaddress.cache.ttl" , "60");
Note that the JVM is a shared resource; multiple Java applications could be using the same JVM.The
TTL value affects all Java applications that use the JVM.
Exception Handling
Understanding how and when the AWS SDK for Java throws exceptions is important in order to build
high-quality applications using the SDK.The following sections describe the different cases of exceptions
that are thrown by the SDK and how to handle them appropriately.
Why Unchecked Exceptions?
The AWS Java SDK uses runtime (or unchecked) exceptions instead of checked exceptions for a few
reasons:
• To allow developers fine-grained control over the errors they want to handle without forcing them to
handle exceptional cases they aren't concerned about (and making their code overly verbose)
• To prevent scalability issues inherent with checked exceptions in large applications
In general, checked exceptions work well on small scales, but can become troublesome as applications
grow and become more complex.
For more information about the use of checked and unchecked exceptions, see the following articles:
• Unchecked Exceptions—The Controversy
• The Trouble with Checked Exceptions
• Java's checked exceptions were a mistake (and here's what I would like to do about it)
AmazonServiceException (and Subclasses)
This is the main type of exception that you'll need to deal with when using the AWS SDK for Java. This
exception represents an error response from an AWS service. For example, if you request to terminate
an Amazon EC2 instance that doesn't exist, EC2 will return an error response and all the details of that
error response will be included in the thrown AmazonServiceException. For some cases, a subclass
of AmazonServiceException will be thrown to allow developers fine grained control over handling error
cases through catch blocks.
When you encounter an AmazonServiceException, you know that your request was successfully sent
to the AWS service, but could not be successfully processed either because of errors in the request's
parameters or because of issues on the service side.
AmazonServiceException has several useful fields in it, including:
• Returned HTTP status code
• Returned AWS error code
• Detailed error message from the service
• AWS request ID for the failed request
AmazonServiceException also includes a field that describes whether the failed request was the
caller's fault (i.e., a request with illegal values) or the AWS service's fault (i.e., an internal service error).
Version v1.0.0
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AWS SDK for Java Developer Guide
Exception Handling