de.smartics.exceptions.sample.lib.resource

Class ResourceService

java.lang.Object

de.smartics.exceptions.sample.lib.resource.ResourceService

public class ResourceService
extends Object

The service to be used by applications. It throws the exception we have designed for the example.

Field Summary

Fields

Modifier and Type	Field and Description
private Logger	log Reference to the logger used by instances of this class.
private static ResourceMessage.Factory	MSG The message factory.
private static String	NAME A name for this service.
private Map<String,Object>	store An in-memory store to make this example simple.

Constructor Summary

Constructors

Constructor and Description
ResourceService() Default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
private void	checkAvailability()
Object	fetchResource(String resourceId) Fetches the resource with the given resourceId.
void	storeResource(String resourceId, Object resource) Stores the resource by the given resourceId.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NAME

private static final String NAME

A name for this service.

Constant Field Value:

"Resource ResourceService"

See Also:

Constant Field Values

MSG

private static final ResourceMessage.Factory MSG

The message factory.

log

private final Logger log

Reference to the logger used by instances of this class.

store

private final Map<String,Object> store

An in-memory store to make this example simple. Usually this would access information in a repository that is backed by a database technology.

Constructor Detail

ResourceService

public ResourceService()

Default constructor.

Method Detail

fetchResource

public Object fetchResource(String resourceId)
                     throws NullPointerException,
                            IllegalArgumentException,
                            ResourceNotFoundException,
                            LibFaultException

Fetches the resource with the given resourceId.

Implementation Notes:

We see here that the exceptions are stacking. If there are 1 to 2 exceptions dealing with preconditions, 1 to 2 for faults that cannot be dealt with by the client and 1 to 2 contingency exceptions, we have a stack of 4 to 5 exceptions under normal conditions.

Parameters:

resourceId - the identifier of the resource to fetch.

Returns:

the resource, never null.

Throws:

NullPointerException - if resourceId is null.

IllegalArgumentException - if resourceId is blank.

ResourceNotFoundException - if there is no resource with the given identifier.

LibFaultException - on any problem accessing the resource layer.

storeResource

public void storeResource(String resourceId,
                 Object resource)
                   throws NullPointerException,
                          IllegalArgumentException,
                          LibFaultException

Stores the resource by the given resourceId.

Parameters:

resourceId - the identifier of the resource to store.

resource - the resource to be stored.

Throws:

NullPointerException - if resourceId or resource is null.

IllegalArgumentException - if resourceId is blank.

LibFaultException - on any problem accessing the resource layer.

checkAvailability

private void checkAvailability()
                        throws IllegalStateException

Throws:

IllegalStateException