Resource

All Known Implementing Classes:

CoAPLDPBasicContainer, CoAPLDPContainer, CoAPLDPDirectContainer, CoAPLDPIndirectContainer, CoAPLDPNonRDFSource, CoAPLDPRDFSource, CoAPLDPResource, CoapResource, ConcurrentCoapResource, DiscoveryResource, ForwardingResource, ProxyCacheResource, ProxyCoapClientResource, ProxyHttpClientResource, StatsResource
```
public interface Resource
```
A resource is an element on the resource tree of a server. Resources are the main building bricks to develop a CoAP server. A resource can have further child resources that again can have children resulting in a tree data structure. A resource must have a name and its URI is defined by the path to the root of the server plus the name. Note that a resource's name is not part of its path. Instead it holds that the URI is defined by URI = path + name where the path is the concatenation of the names of all parents separated and ended with a slash. Assume the following resource tree
```
 Root
  |
  |-- foo
  |    `-- bar
  |         `-- bal
 
```
For resource bal it holds that
```
  bal.getName() equals "bal"
  bal.getPath() equals "/foo/bar/"
  bal.getURI()  equals "/foo/bar/bal"
 
```
A resource is able to respond to CoAP requests. The requests are contained in an instance of type Exchange that contains additional information about the current exchange. The request will always be a complete request and not only a block as defined in the CoAP draft ( http://tools.ietf.org/html/draft-ietf-core-block-12)
When a request arrives at the server, the ServerMessageDeliverer searches in the resource tree for the destination resource. It travels down the resource tree by looking for one element of the destination URI after another and by calling the method getChild(String) on each element. It is allowed to override this method and to return an arbitrary resource. This allows for instance to serve URIs with wildcards or delegate requests to any sub-URI to the same resource.
A resource can have its own Executor. If a resource has such an executor, all requests will be handled by it. Otherwise, the request will be executed on the executor of the parent or transitively the first ancestor that defines its own executor. If no resource up to the root defines its own executor, the currently executing thread will handle the request. A class that implements this interface can export further methods to allow the execution of code on the resource's executor. See CoapResource for an example.

Nested Class Summary

Nested Classes
Modifier and Type Interface and Description

static class Resource.ResourceTreeBuilder

Nested Classes
Modifier and Type	Interface and Description
`static class`	`Resource.ResourceTreeBuilder`

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`add(Resource child)` Adds the specified resource as child.
`void`	`addObserver(ResourceObserver observer)` Adds the specified ResourceObserver.
`void`	`addObserveRelation(ObserveRelation relation)` Adds the specified CoAP observe relation.
`ResourceAttributes`	`getAttributes()` Gets the attributes of this resource.
`Resource`	`getChild(java.lang.String name)` Gets the child with the specified name.
`java.util.Collection<Resource>`	`getChildren()` Gets all child resources.
`java.util.List<Endpoint>`	`getEndpoints()` Gets the endpoints this resource is bound to.
`java.util.concurrent.ExecutorService`	`getExecutor()` Gets the executor of this resource.
`java.lang.String`	`getName()` Gets the name of the resource.
`Resource`	`getParent()` Gets the parent of this resource.
`java.lang.String`	`getPath()` Gets the path to the resource which is equal to the URI of its parent plus a slash.
`java.lang.String`	`getURI()` Gets the URI of the resource.
`void`	`handleRequest(Exchange exchange)` Handles the request from the specified exchange.
`boolean`	`isCachable()` Checks if is the URI of the resource can be cached.
`boolean`	`isObservable()` Checks if this resource is observable by remote CoAP clients.
`boolean`	`isVisible()` Checks if the resource is visible to remote CoAP clients.
`boolean`	`remove(Resource child)` Removes the the specified child.
`void`	`removeObserver(ResourceObserver observer)` Removes the the specified observer.
`void`	`removeObserveRelation(ObserveRelation relation)` Removes the specified CoAP observe relation.
`void`	`setName(java.lang.String name)` Sets the name of the resource.
`void`	`setParent(Resource parent)` Sets the parent of this resource.
`void`	`setPath(java.lang.String path)` Sets the path of the resource.

- Method Detail
  - handleRequest
```
void handleRequest(Exchange exchange)
```
    Handles the request from the specified exchange.
    
    Parameters:
    
    exchange - the exchange with the request
  - getName
```
java.lang.String getName()
```
    Gets the name of the resource.
    
    Returns:
    
    the name
  - setName
```
void setName(java.lang.String name)
```
    Sets the name of the resource. Note that changing the name of a resource changes the path and URI of all children. Note that the parent of this resource must be notified that the name has changed so that it finds the resource under the correct new URI when another request arrives. The easiest way to achieve this is by removing the resource before changing the name and adding it again after the name change.
    
    Parameters:
    
    name - the new name
  - getPath
```
java.lang.String getPath()
```
    Gets the path to the resource which is equal to the URI of its parent plus a slash. Note that that the name of a resource is not part of its path but instead it holds that getURI().equals(getPath() + getName()).
    
    Returns:
    
    the path
  - setPath
```
void setPath(java.lang.String path)
```
    Sets the path of the resource. Note that changing the path of a resource also changes the path of all its children.
    
    Parameters:
    
    path - the new path
  - getURI
```
java.lang.String getURI()
```
    Gets the URI of the resource.
    
    Returns:
    
    the uri
  - isVisible
```
boolean isVisible()
```
    Checks if the resource is visible to remote CoAP clients.
    
    Returns:
    
    true, if the resource is visible
  - isCachable
```
boolean isCachable()
```
    Checks if is the URI of the resource can be cached. If another request with the same destination URI arrives, it can be forwarded to this resource right away instead of traveling through the resource tree looking for it.
    
    Returns:
    
    true, if this resource's URI is cachable
  - isObservable
```
boolean isObservable()
```
    Checks if this resource is observable by remote CoAP clients.
    
    Returns:
    
    true, if this resource is observable
  - getAttributes
```
ResourceAttributes getAttributes()
```
    Gets the attributes of this resource.
    
    Returns:
    
    the attributes
  - add
```
void add(Resource child)
```
    Adds the specified resource as child. Note that the resource should set the correct path of the child when added.
    
    Parameters:
    
    child - the child
  - remove
```
boolean remove(Resource child)
```
    Removes the the specified child. Note that the resource should set the path of the child to null.
    
    Parameters:
    
    child - the child
    
    Returns:
    
    true, if the child was found
  - getChildren
```
java.util.Collection<Resource> getChildren()
```
    Gets all child resources.
    
    Returns:
    
    the children
  - getChild
```
Resource getChild(java.lang.String name)
```
    Gets the child with the specified name. Note that a resource is allowed to return any resource that it likes to associate with that name. This allows to support URIs containing wildcards for example.
    
    Parameters:
    
    name - the name
    
    Returns:
    
    the child
  - getParent
```
Resource getParent()
```
    Gets the parent of this resource.
    
    Returns:
    
    the parent
  - setParent
```
void setParent(Resource parent)
```
    Sets the parent of this resource.
    
    Parameters:
    
    parent - the new parent
  - addObserver
```
void addObserver(ResourceObserver observer)
```
    Adds the specified ResourceObserver. Note that ResourceObserver have nothing to do with CoAP's observe relations (@see addObserveRelation(ObserveRelation). ResourceObserver simply is the observer pattern used in Java to observe a certain object.
    
    Parameters:
    
    observer - the observer
  - removeObserver
```
void removeObserver(ResourceObserver observer)
```
    Removes the the specified observer.
    
    Parameters:
    
    observer - the observer
  - addObserveRelation
```
void addObserveRelation(ObserveRelation relation)
```
    Adds the specified CoAP observe relation. If this resource's state changes, all observer should be notified with a new response.
    
    Parameters:
    
    relation - the relation
  - removeObserveRelation
```
void removeObserveRelation(ObserveRelation relation)
```
    Removes the specified CoAP observe relation.
    
    Parameters:
    
    relation - the relation
  - getExecutor
```
java.util.concurrent.ExecutorService getExecutor()
```
    Gets the executor of this resource.
    
    Returns:
    
    the executor
  - getEndpoints
```
java.util.List<Endpoint> getEndpoints()
```
    Gets the endpoints this resource is bound to. As long as a resource is not added to a server, it should return an empty list. After a resource is added, it should return the endpoint list of its parent. The root of the server will than return the actual list of endpoints.
    
    Returns:
    
    the endpoints

Interface Resource

Nested Class Summary

Method Summary

Method Detail

handleRequest

getName

setName

getPath

setPath

getURI

isVisible

isCachable

isObservable

getAttributes

add

remove

getChildren

getChild

getParent

setParent

addObserver

removeObserver

addObserveRelation

removeObserveRelation

getExecutor

getEndpoints